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Drainage Reports - 03/30/2015
L 1 1 n 1 1 I AVAGO TECHNOLOGIES- BUILDING 3 AND SITE DEVELOPMENT DRAINAGE REPORT CITY OF FORT COLLINS, COLORADO REV. MARCH 13TH 2O15 REV. FEBRUARYIITH 2O15 JANUARY28TH 2O15 MARTINIMARTINPROJECT NO. 14.0833 COY of Ft., Collin pproJ fans Appred B — °Dateov3?0 PREPARED FOR: AVAGO TECHNOLOGIES (APPLICANT) 4380 ZIEGLER ROAD FORT COLLINS, CO 80525 (970)288-0344 PAUL TANGUAY PREPARED BY: PRINCIPAL IN CHARGE: PROJECT MANAGER: PROJECT ENGINEER: MARTIN/MARTIN, INC. 12499 WEST COLFAX AVENUE LAKEWOOD, COLORADO 80215 PHONE: (303) 431-6100 MATTHEW B. SCHLAGETER, P.E. PETER S. BUCKLEY, P.E. RYAN J. STRATMAN, E.I.T. I TABLE OF CONTENTS ' A. GENERAL LOCATIONAND DESCRIPTION ...................................... 2 ' Al. LOCATION............................................................................................................. 2 AZ DESCRIPTION OF PROPERTY........................................................................... 3 A3. FLOODPLAIN SUBMITTAL REQUIREMENTS ............................................... 4 B. DRAINAGE BASINS AND SUB -BASINS .............................................. 4 ' Bl. MAJOR BASINDESCRIPTION........................................................................... 4 B2. SUB-BASINDESCRIPTION................................................................................. 4 ' C. DRAINAGE DESIGN CRITERIA........................................................... 6 Cl. REGULATIONS...................................................................................................... 6 C2. DIRECTLY CONNECTED IMPERVIOUSAREA DISCUSSION........ 7 (DCLA) ' C3. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS ................ 9 C4. HYDROLOGICAL CRITERIA.............................................................................. 9 ' CS. HYDRAULIC CRITERIA..................................................................................... 10 C6. FL OODPLAIN REGULATIONS COMPLLONCE.............................................11 ' C7. MODIFICATIONS OF CRITERIA.....................................................................11 ' D. DRAINAGE FACILITY DESIGN......................................................... Il DI. GENERAL CONCEPT.........................................................................................11 D2. SPECIFIC DETAILS........................................................................................... 12 ' E. CONCLUSIONS...................................................................................... 16 El. COMPLIANCE WITH STANDARDS................................................................. 16 E2. DRAINAGE CONCEPT.......................................................................................16 F. REFERENCES.......................................................................................18 ' G. APPENDICES........................................................................................ 19 ' 1 A. GENERAL LOCATIONAND DESCRIPTION AI. LOCATION The Avago Technologies - Building 3 and Site Development (hereafter referred to as "PROJECT") site is located on the Avago/Hewlett-Packard Campus (hereafter referred to as "CAMPUS") in Lot 2 of the Preston -Kelley 2od Subdivision, found in the Southwest''/, of Section 33, Township 7 North, Range 68 West of the 6 h Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. The PROJECT address is 4380 Ziegler Road. The overall CAMPUS is bound to the north by Hidden Pond Drive, to the east by the Fossil Creek Drainage Ditch, to the south by East Harmony Road, and to the West by Ziegler Road. The PROJECT site is bound to the north by the existing private Loop Road, to the east by existing buildings and the existing courtyard area, to the south by existing landscaped areas and private Loop Road, and to the west by private Loop Road. Refer to the vicinity map below and in the Appendix. Figure 1: Vicinity Map, NTS I I n I LJ ,' L� AZ DESCRIPTION OF PROPERTY The overall site consists of 28.21 acres of disturbed area. Native grasses, existing asphalt or concrete drives, parking areas, and existing buildings cover the existing site area. According to the "Geotechnical Engineering Report" produced by Terracon Consultants, dated January 19, 2015, the existing soils consist of fill materials consisting of lean clay with various amounts of sand and gravel. Based on the results of borings, bedrock is located at a maximum depth of exploration of 40 feet. Groundwater was observed at a maximum elevation of 4908.2', and a minimum depth of 6' below existing grade. The soils on -site are typically SCS Type C Hydrologic Soils. A USDA web soil survey of the CAMPUS states that the soils consist mostly of Nunn clay loam. A copy of the web soil survey is referenced in the Appendix. The proposed development will include the construction of Building 3, private asphalt and concrete drives and parking lots, porous pavement drives and parking lots, two detention and water quality ponds, and utility infrastructure necessary to service the proposed building. The footprint of the building expansion covers approximately 66,000 SF. Additionally, drainage facilities designed to improve Stormwater Quality are proposed for the site in accordance with Section 3.4.3 Water Quality of the City of Fort Collins Municipal Code. The PROJECT design includes the construction of both North and South Ponds (hereafter referred to as "PROJECT North Pond and PROJECT South Pond") that will provide detention and treat water quality for the 100-year storm for the added impervious area with the proposed PROJECT development. An existing grade break exists on the project site that directs runoff north or south. This grade break was maintained when designing the site in order to maintain the total tributary area to each pond. The elevation of the groundwater at the southern half of the site limited the design of the PROJECT South Pond. The pond bottom was designed to be above the groundwater ' elevation so that the pond would not fill with groundwater. The relatively high pond bottom meant that the existing storm sewer could not be used to get storm water into the pond. Thus, overland flow is the design method for getting runoff into the PROJECT 3 G I South Pond. A copy of the groundwater table and borings map can be found in the IAppendix. A3. FLOODPLAINSUBMITTAL REQUIREMENTS The proposed design is in accordance with the "City of Fort Collins Floodplain Review ' Checklist for 50% Submittals." ' B. DRAINAGE BASINS AND SUB -BASINS ' BL MAJOR BASINDESCRIPTION The CAMPUS lies entirely within the Fox Meadows Drainage Basin which is approximately bounded by Horsetooth Road on the north, Harmony Road on the south, the Cache de La Poudre River and I-25 on the east, and Lemay Avenue on the west. A Master Plan for the Fox Meadows Drainage Basin was prepared by Resource Consultants, Inc., in 1981. In this master report, the CAMPUS is located within Basin H. This area was studied again by Nolte and Associates in 1990 when a master drainage plan was prepared for the CAMPUS (this report hereafter referred to as "MASTER"). The MASTER did not alter any of the assumptions or conclusions which were made in the Fox Meadows Master Drainage Plan. ' The site is part of the Flood Insurance Rate Map (FIRM) as prepared by the Federal Emergency Management Agency (FEMA). The site is within FIRM — Panel No. 08069CO994F last revised December 19, 2006. The FIRM shows that the site is outside of the 500-year floodplain, and is included in the Appendix of this report. ' BZ SUB -BASIN DESCRIPTION The northern portion of the PROJECT site is located within Basin 32 of the MASTER report. Basin 32 discharges to a regional channel located along County Road 9 and the ' north boundary of the CAMPUS. The regional channel was recommended in the MASTER report and was designed and built with the Hewlett-Packard Building 5 project. The channel was designed for the 100-year storm and discharges to the north regional detention pond on the CAMPUS (this report hereafter referred to as "CAMPUS 4 II North Pond"). It was modified during Building 4 construction to ensure that uncontrolled spilling into the Fossil Creek Ditch from the regional detention ponds does not occur during the 100-year storm. The southern portion of the proposed PROJECT site is currently captured in storm infrastructure and is routed southeast to the on -site detention ponds. Stormwater detention and water quality treatment for the CAMPUS is currently provided by four on -site ponds located in the SE corner of the CAMPUS on HP property. These ponds are constructed as Extended Detention Basins (EDBs). The North Pond is a dry bottom pond. The South Pond, Southwest Pond, and Dam Pond are wet ponds. Added water quality benefits are gained via the regional channel along the north side of the campus which is constructed as a Grass Swale. This channel provides initial water quality treatment to the north - flowing basins in the PROJECT area prior to treatment in the CAMPUS ponds. All existing CAMPUS ponds are hereafter referred to as "CAMPUS North/South/Southwest/Dam Pond". A map of the CAMPUS showing the existing and proposed ponds is shown below. PROPOSED DRAINAGE EXHIBIT Figure 2: Existing and Proposed Ponds and Drainage 5 j The Building 4 (134) West Annex addition is currently under construction. No detention facilities are being added with the Building 4 project even though impervious area was added to the site. The improvements for Building 4 were designed to .balance the impervious area by removing existing parking lots to account for the new Building 4 roof and paved areas. C. DRAINAGE DESIGN CRITERIA ' C1. REGULATIONS ' The drainage design of the B3 project is in compliance with the following criteria: i) Article VII, Stormwater Utility, City of Fort Collins Municipal Code, latest revision ("hereafter referred to as the "CRITERIA"). LJ I LJ ii) Section 3.4.3, Water Quality, City of Fort Collins Municipal Code, latest revision. iii) "Urban Storm Drainage Criteria Manual' latest revision (hereafter referred to as the "MANUAL"). This drainage report varies from the CRITERIA because the V=KA method was used for pond volume determination instead of the FAA method. Volume calculated using the FAA method was substantially less than the volume calculated using the V=KA method. Therefore, the larger storage volumes calculated in the V=KA method will be used. Detention volume calculations for both methods have been provided in the appendix of this report for reference. See the table below for the detention volume method summary. REQUIRED DETENTION REQUIRED DETENTION VOLUME CALCULATED VOLUME CALCULATED USING MODIFIED V=KA USING MODIFIED FAA METHOD METHOD CAMPUS NORTH POND 0.242 AC -FT 0.0804 AC -FT CAMPUS SOUTH POND 0.346 AC -FT 0.0876 AC -FT Table 1: Detention Volume Method Summary 0 e 11 I t 11 I I fl I 1 11 I C2. DIRECTLY CONNECTED IMPERVIOUS AREA (DCIA) DISCUSSION The PROJECT site was designed to minimize the Directly Connected Impervious Area. This was accomplished by incorporating a variety of Low -Impact -Design ("LID") features into the drainage design for this project. The following are descriptions of the LID features used in the PROJECT design: Grass Swale: The site has been designed with grass swales which have been designed in accordance with the Grass Swale Best Management Practice Fact Sheet and Design Spreadsheet from the MANUAL. There are four proposed grass swales on the B3 site. Both the PROJECT North and South Pond bottoms contain grass swales directing storm water to the pond outlet structure. Another grass swale located to the west of the proposed B3 building will except and treat runoff from the B3 roof, porous pavers, drives and walks, and landscape areas in front of the proposed building. The B3 roof drains to roof drains which flow into rock boxes at the base of the building which overflow into the grass swale in front of the B3 Building. The Grass Swales will be densely vegetated trapezoidal channels with low-pitched side slopes and a relatively broad cross sections which will convey flow in a slow and shallow manner, thereby facilitating sedimentation and filtering while limiting erosion. Underdrain systems have been provided for the Grass Swales in order to encourage infiltration and limit ponding. A narrow width of cobble shall be placed at the invert of the grass swales. Rock Box: Runoff from roof drains from the proposed building will discharge via lamb's tongues at the building face into one of two proposed rock boxes. Rock boxes are constructed from CDOT Type D Inlets approximately 48" in height. Rock Boxes are designed to facilitate sedimentation and provide energy dissipation for roof drain runoff. The Rock Box utilizes a layer of rip -rap or cobble at its top in order to first slow down and dissipate roof drain flows. Next, these flows filter down through approximately 3' of 1-2" crushed rock in order to encourage sedimentation and filtration. An orifice plate mounted to the front of 7 I the rock box provides for the slow discharge rate out of the rock box into the level spreader. Level Spreaders have been incorporated into the drainage design in order to limit erosion by reducing flow velocities and flow concentration. Two level spreaders are proposed for the B3 project, one at each rock box. The level spreader functions by providing a small sedimentation basin (approximately 3" depth) for flows. This sedimentation basin discharges over the level spreader at a constant elevation, thereby creating sheet flow as runoff discharges into a proposed grass buffer. Grass Buffer: From the level spreaders, sheet flow runs through grass buffers before entering the grass swale in front of the B3 building. Grass Buffers play an important role in LID by enabling infiltration and slowing runoff. The Grass Buffer provides the benefits of filtering sediment and reducing directly connected impervious areas. Multiple Roof Drains and Disconnecting Impervious Area (DCL9): The roof drainage from the B3 building has been purposely broken up into multiple discharge points along the perimeter of the building in order to disconnect impervious areas which lengthens runoff times of concentration and allows for multiple localized areas for water quality treatment. Porous Pavement: Porous pavers allow the movement of water to layers below the pavement surface. These help provide full treatment and slow release of the WQCV while reducing the overall site imperviousness. Porous pavers were used in the design to comply with the LID Criteria that states, "No less that twenty five percent (25%) of any newly added pavement areas must be treated using a permeable pavement technology that is considered an LID technique." The site was designed so that this criteria would be met by adding porous pavers to the site. An additional 3,669 SF of porous pavers were added to the site to give Avago a `pavement development credit.' This `Pavement development credit' means that the Avago campus property will remain in compliance with the City's 8 LID criteria for pavement development for up to 14,676 SF of future non -porous pavement area has been added to the site (and without providing additional porous pavement). A summary table of the porous pavers is shown below. TOTAL NEW PAVEMENT FOR B3 192,058 SF (4.41 AC) PROJECT MINIMUM REQUIRED POROUS 48,015 SF (1.10 AC) = 25% OF PAVEMENT TOTAL NEW PAVEMENT FOR B3 PROVIDED POROUS PAVERS FOR 51,684 SF (1.19 AC) B3 PROJECT ADDITIONAL POROUS PAVERS 3,669 SF 0.08 AC FUTURE `PAVEMENT 14,676 SF (0.34 AC) = 4 X DEVOLOPMENT CREDIT' ADDITIONAL POROUS PAVERS Table 2: Porous Pavement Summary C3. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS The master planned ponds described in Section B.2 of this report are assumed to be at their design capacity with the previous development on the Avago Campus (the B4 West Annex Development). This couples with the fact that the CAMPUS Ponds are located on HP property and not Avago property means that the CAMPUS Ponds will not be modified. As such, the PROJECT North and South Pond designs provide 100-year detention and water quality treatment for the added impervious area in the north and south flowing basins. The PROJECT North Pond design provides more than the required 100-year detention and water quality treatment for the newly added impervious area upstream of the existing regional detention ponds and the added cut from the pond is being used as fill for the new building. C4. HYDROLOGICAL CRITERIA Design runoff is calculated using the Rational Method as established in the MANUAL. The 100-year, one -hour point rainfall data is 2.86 inches per the CRITERIA. Detention discharge and storage volume is calculated using the empirical V=KA method where A is added impervious acres. Storage calculations utilizing the modified FAA method have been provided in accordance with the City of Fort Collins Criteria. For both the proposed North and South Ponds, the V=KA method requires a larger storage volume for the proposed development. As such, the more conservative V=KA method was utilized in 9 I I I I l I I I determining required storage values. See Table 1 in Section C.1 for a detention method summary using both methods. The calculations for both methods is included in the Appendix of this report. Storage and water quality volume is provided for net added impervious area only. The design is per the 100-year storm only. In accordance to the MANUAL, a frequency factor was implemented in the determinations of runoff coefficients. Composite runoff coefficients are shown in the table below and are in accordance with the MANUAL. 100-Year Composite Runoff Coefficient Roofs 1.00 Drives and Walks 1.00 Landscape 0.13 Porous Pavers 0.63 Table 3: Composite Runoff Coefficients C5. HYDRAULIC CRITERIA Final pipe sizes and water surface profiles have been calculated using the Bentley StormCAD program, latest edition per the MANUAL. Inlet sizes were calculated using the UD-Inlet Spreadsheet, latest edition. The PROJECT North Pond spillway is designed so that the spillway crest is a minimum of P below the top of the pond. Allowance for future development is available in the PROJECT North Pond and this pond will have a maximum depth of 6' . The PROJECT South Pond was designed so that the maximum ponding depth is 6' after the B3 development. The PROJECT South Pond does not have an overflow spillway because it is located at the low point of the site. The PROJECT South Pond spills into the circular porous paver area to the northeast at an elevation of 491 1.50. Overflow runoff will then flow east into an existing inlet that discharges into the existing 36" storm line that flows into the CAMPUS Southwest pond. In the event where the pond outlet structure and the existing inlet are both clogged, runoff will flow east over the proposed private road and existing parking lot at an elevation of 4915.00 via overland path to the CAMPUS Southwest Pond. Both ponds release runoff through an orifice plate to restrict for the allowable water quality and 100-year release rates. The PROJECT north ponds emergency spillway is a broad -crested weir that is sized to release water at two times the 100-year pond inflow that was determined by the rational method. 10 I I S I I I I I I I I C6. FLOODPLAINREGULATIONS COMPLL4NCE No variances from the CRITERIA are requested at this time. C7. MODIFICATIONS OF CRITERL4 The only variance from the CRITERIA was the use of the V=KA method for pond detention volumes instead of the FAA method. This is justified because the V=KA method was more conservative as it requires a larger volume. D. DRAINAGE FACILITY DESIGN D1. GENERAL CONCEPT Proposed Basin A includes existing and proposed parking lots, (including some proposed porous paver areas), some existing and proposed landscape areas, and a portion of Loop Road. Basin A discharges north to the proposed PROJECT North Pond via existing storm sewer and overland flow. The existing storm sewer through this basin is to be rerouted and daylight into the southeast corner of the proposed PROJECT North Pond via proposed 30" pipe. An existing storm line carrying flow from two existing inlets on Loop Road that currently runs under the proposed pond will be cut and enter the proposed PROJECT North Pond from the west via proposed 2 1 " pipe. From the pond outlet structure, flow is routed via proposed storm sewer to an existing storm line that carries flow to the regional channel. From the regional channel, flow enters the CAMPUS North Pond, which then flows into the CAMPUS South Pond, which then flows into the CAMPUS Dam Pond before flowing off -site. Basin B consists of the proposed B3 building, landscaping, proposed grass swales, proposed porous paver areas, proposed drives and walks, and a portion of Loop Road. Basin B 1 discharges south to an existing storm line and Basin B2 discharges southeast to the proposed Storm Line A. In the event that a storm line in Basin B becomes overwhelmed and backs up, stormwater will travel via overland path to the PROJECT South Pond. Under normal circumstances, all of Basin B circumvents the PROECT South 11 I 1. I I I 11 I I H I I I Pond. All of Basin B ultimately ends up in the existing 36" storm sewer outfall and the CAMPUS Southwest Pond. Basin C discharges south via overland flow to the proposed PROJECT South Pond. Basin C includes portions of Loop Road, existing and proposed drives and walks, existing and proposed landscape areas, and proposed porous paver areas. During the water quality storm, runoff can infiltrate through the porous pavers into a proposed underdrain that connects to an existing 36" storm line and bypass the pond. For storms larger than this, all runoff will enter the PROJECT South Pond via overland flow. From the proposed PROJECT South Pond, flow is conveyed into an existing storm sewer that conveys flow into the CAMPUS Southwest Pond, which then flows into the CAMPUS South Pond, which then flows into the CAMPUS Dam Pond before flowing off -site. Basin D includes the proposed building bridge between the proposed B3 building and the existing B4 building expansion, portions of the proposed B3 building roof, proposed drives and walks, the existing courtyard area east of the proposed B3 building, a portion of Loop Road, and proposed and existing landscape areas. Under normal circumstances, flow from Basins D1, D3, and D4 is conveyed via proposed storm sewer to an existing 36" storm sewer to the south. In the event that the existing storm sewer in the courtyard becomes surcharged or clogged, runoff from Basin D2 can flow via proposed storm pipe to Storm Line A and vice -versa. From the existing storm sewer, flow is conveyed into the CAMPUS Southwest Pond, which then flows into the CAMPUS South Pond, which then flows into the CAMPUS Dam Pond before flowing off -site. In the event that both the proposed and existing storm sewers from the courtyard become plugged, two 3' wide x 1' high box culverts have been placed under the building connection between Building 1 and Building 3 to allow for an emergency overflow path. D2. SPECIFIC DETAILS Basin A 1 consists of approximately 8.18 acres of parking, native grasses, porous pavers, and the proposed PROJECT North Pond. The proposed porous pavers in this basin have an underdrain designed to convey runoff to the existing 30" RCP storm sewer that flows north. The 30" RCP storm sewer is proposed to flow into the proposed PROJECT North 12 I I I I 1 11 1 I I L� Pond by adding a proposed manhole and rerouting the line via proposed storm line into the pond via a 30" pipe. Runoff from the existing native grass area between the proposed parking lots and the proposed PROJECT North Pond shall flow into the pond via overland flow. Two existing inlets in Loop Road currently convey runoff into the existing 21" RCP storm line, but it is proposed to cut the existing storm line so it flows directly into the west side of the proposed PROJECT North Pond. Once in the pond, a cobble swale conveys runoff to the outlet structure, where water is released at allowed rates into a proposed storm line that connects to the existing 30" RCP storm sewer further downstream. All of the existing 30" RCP storm sewer in between where runoff enters and leaves the pond is to be abandoned in place because it is beneath an existing berm. See plans for pond access information and location. Basin A2 consists of approximately 1.11 acres of parking and landscape area. Runoff from the parking lot in Basin A2 is routed to a proposed inlet in the southeast corner of the parking lot. This inlet connects to the existing 30" RCP storm sewer that flows north into the PROJECT North Pond. Basin B 1 consists of approximately 3.17 acres of drives, walks and landscaping. Basin BI is collected by a proposed area inlet, a proposed curb inlet, and an existing curb inlet. A proposed area inlet will collect runoff from the landscape area at the top of Basin B 1. A proposed curb inlet will collect runoff from the parking lot in Basin B 1. There is an existing curb inlet that will remain in place that collects runoff from a parking area. All of these inlets are to be connected to the existing storm line that runs south into the CAMPUS Southwest Pond. Basin B2 consists of approximately 2.55 acres of the proposed B3 building roof, porous paver areas, drives and walks, and landscaping. Runoff from the roof of the proposed B3 building discharges though roof drains into two proposed rock boxes. The rock boxes are designed to improve downstream water quality by promoting sedimentation. and allowing for discharge to the surface that enables other LID infiltration methods. From the rock boxes, discharge enters a level spreader and then enters a grass buffer before entering the grass swale. Two proposed porous paver underdrains connect to this grass Swale 13 1 I 1 I I I u I 1 I 1 underdrain along with roof drains and area inlets. The grass swale contains an underdrain to distribute water along the length of the swale. Downstream, the underdrain connects to two more area inlets and eventually connects via wye connection to Storm Line A. Discharge from basin B2 will ultimately go to the CAMPUS Southwest Pond. During storms greater than the I00-year event, runoff will flow over the landscape area between the proposed grass swale and the proposed handicap parking stalls. This overflow was designed to release stormwater before it backs up against the B3 building. This flow will run into the PROJECT South Pond via overland path. Runoff from the porous pavers will flow into the PROJECT South Pond via overland path during the 100- year storm. Basin C 1 consists of approximately 7.93 acres of drives and walks, porous paver area, landscaped areas, and the proposed PROJECT South Pond. All runoff from Basin C I flows via overland flow into the proposed PROJECT South Pond. During the minor storm event, runoff can infiltrate through the porous pavers into an underdrain that conveys flow into an existing 36" storm sewer. During the 100-year storm, runoff will run directly into the proposed PROJECT South Pond via overland flow. The existing native grass area south of the proposed pond can flow into the pond via overland flow. A grass Swale with cobble culvert conveys water in the pond to the pond outlet structure. The pond outlet structure will release water at allowable rates into the existing 36" RCP storm sewer that takes flow to the existing CAMPUS Southwest Pond. See plans for pond access information and location. Basin D1 consists of approximately 5.61 acres of proposed B3 building roof, an existing drive, and landscaped areas. Runoff from the proposed bridge connecting the B3 and B4 buildings will be routed into roof drain downspouts that will be collected and routed to Storm Line A. Runoff from landscaped areas, an existing trench drain, and a concrete drive north of the B3 building will be directed into two proposed Type C Inlets in Basin DI that are part of Storm Line A. Basin D2 consists of approximately 2.36 acres of existing courtyard area with walks and landscaping. Storm Line A flows south collecting flow from roof drains from the B3 14 1 1. building to a proposed Type D Inlet in Basin D2. This proposed inlet is adjacent to an ' existing storm manhole that is proposed to be removed and replaced with a Type C Inlet. A pipe will be built between the proposed inlets higher than the storm lines they are each connected to. Under normal conditions, the existing Type C Inlet will flow into the - existing storm line, but in a scenario where the existing storm line becomes surcharged or ' clogged, stormwater runoff can flow via the proposed higher storm pipe into the proposed Type D Inlet and vise -versa. Additionally, there is an emergency overland flow path for runoff to pass through between the existing Building 1 and the proposed B3 building. Basin D3 consists of approximately 0.70 acres of a concrete loading dock area. Storm Line A from drains, drain, inlets in loading dock collects runoff roof a trench and area the ' area. Storm Line A then collects runoff from the storm line from Basin B2 via wye connection. ' Basin D4 consists of approximately 1.19 acres of landscaped areas and a proposed private drive. Storm Line A ends in Basin D4 with a proposed manhole connecting an existing 36" RCP storm sewer in the proposed private drive. Two curb inlets are located in the proposed private drive on both sides of the manhole at the end of Storm Line A. Runoff from Basin D4 is to be collected in the two curb inlets in the private drive and routed via existing storm sewer to the CAMPUS Southwest Pond. The PROJECT North Pond was designed to detain and treat more than what was required with the added imperviousness of the site in order to generate fill for the B3 project and ' also to provide additional capacity in the event more development occurs in this basin. The PROJECT South Pond was designed for the added PROJECT impervious area only. An easement is proposed for the PROJECT North Pond to the future maximum 100-year WSEL. The easement for the PROJECT South Pond is to the PROJECT design 100-year t WSEL. CDOT Type D Inlets will be used as outlet structures for both the PROJECT North and South Ponds. Flow control plates were sized for both the water quality release as well as the 100-year release. For both ponds, the invert of the 100-year release hole on the plate was set at the WQCV WSEL and the top of the plate ends at the 100-year plus the 1 15 WQCV elevation. The PROJECT North Pond has a space between the plate and the top of the vault that will act as an overflow spillway into the box. The PROJECT North Pond outlet structure was designed to be oversized so that it can function with minor modifications, in case any future flow is sent to that pond with any future developments. Details on the outlet structures and flow control plates can be found in the Appendix of this report. Drainage issues arose when designing the PROJECT South Pond. Groundwater is shallow where the PROJECT South Pond was proposed to be built. The solution was to grade the pond wide and shallow to be above the groundwater surface elevation. The ponds summary table is shown in Table 4 below. Pond Required Provided Water Quality Water Spillway Pond Outlet Detention Detention Capture Volume Quality Elevation Freeboard Size Pond Volume Pond Volume (WQCV) (AC -FT) Elevation AC -FT) AC -FT North Pond 0.242 2.84 0.055 4916.06 4922.30 1' 18" South Pond 0.346 1.00 0.078 4910.38 4911.50 1' 15" Table 4: Ponds Summary Table E. CONCLUSIONS El. COMPLIANCE WITH STANDARDS The Drainage Report for the Avago Building 3 and Site Development project has been prepared in compliance with the MASTER, CRITERIA, MANUAL, and the City of Fort Collins Municipal Code, Section 3.4.3 Water Quality. The proposed drainage design is consistent with both existing and developed conditions. E2. DRAINAGE CONCEPT Developed runoff will be collected and conveyed by a system of overland flow, grass swales, and proposed and existing storm sewer. Runoff will be directed into the two proposed water quality and detention ponds or straight into the existing storm sewer and ultimately be conveyed to existing regional detention and water quality ponds located in the SE corner of the CAMPUS. LID principles will improve the water quality for 16 I stormwater runoff from the developed site. Development of the site is not anticipated to ' adversely impact downstream properties or drainage facilities. 1 I 1 I 17 r 1 1 1 1 F. REFERENCES 1. "Updated Hydrology for the Fox Meadows Basin". Resource Consultants. 1987. 2. "Master Drainage Report for Hewlett-Packard Site". Nolte and Associates. 1990. 3. "City of Fort Collins Municipal Code". Latest revision 4. "Hewlett-Packard Building 5 Drainage Report". Sear -Brown Group. 1996. 5. "Hewlett-Packard Building 4 Drainage Report". Sear -Brown Group. 1999. 6. "Symbios Logic Site Development". Sear -Brown Group. 1997 7. "Detailed Hydraulic Study, Regional Detention Facilities, Hewlett-Packard Company". Sears Brown Group. 2000. 8. "Geotechnical Engineering Report, Avago Building 3". Terracon Consultants, Inc. January 19, 2015. 9. "Avago Technologies — Building 4 West Annex Expansion and Site Development Drainage Report". Martin/Martin, Inc. March 25, 2013. 10. "Urban Drainage and Flood Control District Drainage Criteria Manual Vol. 1, 2 and 3", Wright-McLauglin Engineers, 2001 18 11 1 1 [1 1 1 r 1 G APPENDICES 1 i 1 1 1 i 1 i 1 19 I 1 1 1 ' MAPS AND DESIGN AIDS VICINITY MAP RAINFALL DATA USDA SOIL SURVEY FEMA FIRMMETTE INLET CAPACITY CITY OF FORT COLLINS WATER QUALITYMUNICIPAL CODE GRASS BUFFER BMP GRASS SWALE BMP GROUNDWATER MEASUREMENTS i ' MAPS AND DESIGN AIDS - VICINITY MAP Google earth feet 3000 meters 900 MAPS AND DESIGN AIDS -RAINFALL DATA Table RA-8 City of Fort Collins Rainfall Intensity--Duration-Frequene`- Table for Use with the Rational Method Duration (min) 2-Year Intensity (rudhr) 10-Year Intensity (Uvhr) 100-Year Intensity Onmr) 31 1.27 2.16 4.42 32 1.24 2.12 4.33 33 1.22 2.08 4.24 34 1.19 2.04 4.16 35 1.17 2 4.08 36 1.15 1.96 4.01 37 1.16 1.93 3.93 38 1.11 1.89 3.87 39 1.09 1.86 3.8 40 1.07 1.83 3.74 41 1.05 1.8 3.68 42 1.04 1.77 3.62 43 1.02 1.74 3.56 44 1.01 1.72 3.51 45 0.099 1.69 3.46 46 0.98 1.67 3.41 47 0.96 1.64 3.36 48 0.95 1.62 3.31 49 0.94 1.6 3.27 50 0.92 1.58 3.23 51 0.91 1.56 3.18 52 0.9 1.54 3.14 53 0.89 1.52 3.1 54 0.88 1.5 3.07 SS 0.87 1.48 3.03 56 0.86 1.47 2.99 57 0.85 1.45 2.96 58 0.84 1.43 2.96 59 0.83 1.42 2.89 60 0.82 1.4 1 186 d O 1 O uQ a a n m m O �n n � ry rn ry m P ua m V m e d C N u N u N N 1TI a C W V u N q W ry W m a O Y N a p 0 0 O .. C a O— n W N% d C O n .O O C L n rJ n C n f O C CE: ccnn coE� c'$c �E� con coo 00o aE� `o = v Q .aqa U n oAa LL n mN o J vi A.,oa J Ul n o 0 O N o'�`d J n Z O N Z •. N N v1 N mm H n e � of C A m n a A J S in N N vl m O �O N �O m i0 O D m n R n O O O H MAPS AND DESIGN AIDS - FEMA FIRM 3135000 FT JOINS PANEL 0992 GRAND TETON PL ZONE X MARIAH LN Larimer County Unincorporated Areas 080101 CHINOOK LN 33 �o ZONE X 0 N N r t A A D � F 'A HARMONY RD O LL W a Z U `1r:"k� ZONE AE ZONE X— FLOODING EFFECTS ZONE IX 1- 25 DIVIDED FLOW CACHE LA POUDRE RIVER 7 ZONE AE MAP SCALE 1" = 500' METERS 150 300 PANEL 0994F FLOOD INSURANCE RATE MAP LARIMER COUNTY, COLORADO AND INCORPORATED AREAS PANEL 994 OF 1420 (SEE MAP INDEX FOR FIRM PANEL LAYOUT) AUNITY NUMBER PANEL SUFFIX COLLINS. CITY OF 080102 0994 F ER COUNTY 080101 o994 F to User: The Map Number shown below i be used when placing map orders; the nunity Number shown above should be on insurance applications for the subject ZONE X yMAP NUMBER 08069CO994F ND 5£G EFFECTIVE DATE �q DECEMBER 19, 2006 ederal Emergency Management Agency This is an otlicial copy of a portion of the above referenced flood map It was extracted using F-MIT On -Line. This map does not reflect changes or amendments which may have been made subsequent to the date on the (n title block. For the latest product information about National Flood Insurance F- Program flood maps check the FEMA Flood Map Store at www. mec.ferns gov x STORM DRAINAGE DESIGN AND TECHNICAL CRITERIA 30.0 28.0 26.0 24.0 22.0 20.0 u 18.0 16.0 m a 14.0 U m 12.0 c 10.0 8.0 6.0 4.0 2.0 0.0 Figure 8.1. Allowable Inlet Capacity- Sump Conditions Note: See Section 8.3.2 for assumptions. Type 16 and Type 14 Inlets for Sump Conditions r ter' r' 1 , 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 Water Depth (Inches) -Single No.16 Combination Double No.16 Combination -Triple No.16 Combination --• -- 6at No.14 -. - 9- t No.14 - -12dt No.14 Allowable Inlet Capacity for Type C and D Inlets for Sump Conditions 4u.0 35.0 30.0 9 25.0 Z^ o. 20.0.0000/ m U m 15.0 ---------- 10.0 5.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 Water Depth (inches) ----Type C Type D 01 /2006 City and County of Denver INLETS IRCI MAPS AND DESIGNAIDS -CITY OF FORT COLLINS WATER QUALITY 1 MUNICIPAL CODE 3.4.3 Water Quality The development must comply with all applicable local, state and federal water quality standards, including, but not limited to, those regulating erosion and sedimentation, storm drainage and runoff control, and the treatment of solid wastes, and hazardous substances. Projects must be designed such that all runoff draining from development sites is treated in accordance with the criteria set forth in the Stormwater Criteria Manual. Stormwater control and treatment measures may include, but are not limited to: • grass buffers • grass swales • bioretention (rain garden or porous landscape detention) • extended detention basins • constructed wetland ponds • sand filters • retention ponds • constructed wetland channels ' • permeable pavements (Ord No. 051, 2012 §11, 7/17112) n i 1 1 r I I I I I I I I MAPS AND DESIGNAIDS - URBAN DRAINAGE GRASS BUFFER Grass Buffer T-1 Description Grass buffers are densely vegetated strips of grass designed to accept sheet flow from upgradient development. Properly designed grass buffers play a key role in LID, enabling infiltration and slowing runoff. Grass buffers provide filtration (straining) of sediment. Buffers differ from swales in that they are designed to accommodate overland sheet flow rather than concentrated or channelized flow. Site Selection Grass buffers can be incorporated into a wide range of development settings. Photograph GB-1. A flush curb allows roadway runoff to sheet flow Runoff can be directly accepted from a through the grass buffer. Flows are then further treated by the grass parking lot, roadway, or the roof of a swale. Photo courtesy of Muller Engineering. structure, provided the flow is distributed in a uniform manner over the width of the buffer. This can be achieved through the use of flush curbs, slotted curbs, or level spreaders where needed. Grass buffers are often used in conjunction with grass swales. They are well suited for use in riparian zones to assist in stabilizing channel banks adjacent to major drainageways and receiving waters. These areas can also sometimes serve multiple functions such as recreation. Hydrologic Soil Groups A and B provide the best infiltration capacity for grass buffers. For Type C and D soils, buffers still serve to provide filtration (straining) although infiltration rates are lower. Designing for Maintenance Recommended ongoing maintenance practices for all BMPs are provided in Chapter 6 of this manual. During design the following should be considered to ensure ease of maintenance over the long-term: Where appropriate (where vehicle safety would not be impacted), install the top of the buffer 1 to 3 inches below the adjacent pavement so that growth of vegetation and accumulation of sediment at the edge of the strip does not prevent runoff from entering the buffer. Alternatively, a sloped edge can be used adjacent to vehicular traffic areas. Amend soils to encourage deep roots and reduce irrigation requirements, as well as promote infiltration. Grass Buffer Functions LID/Volume Red. Yes W CV Capture No W CV+Flood Control No Fact Sheet Includes EURV Guidance No Typical Effectiveness for Targeted Pollutants3 Sediment/Solids Good Nutrients Moderate Total Metals Good Bacteria Poor Other Considerations Life -cycle Costs Low 3 Based primarily on data from the International Stormwater BMP Database (www. bmodatabase.ore). November 2010 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 GB-1 I u J MAPS AND DESIGN AIDS - URBAN DRAINAGE GRASS BUFFER T-1 Grass Buffer ■ Design and adjust the irrigation system (temporary or Benefits permanent) to provide water in amounts appropriate for the selected vegetation. Irrigation needs will change from Filters (strains) sediment and month to month and year to year. trash. ■ Protect the grass buffer from vehicular traffic when using Reduces directly connected this BMP adjacent to roadways. This can be done with a impervious area. (See Chapter 3 slotted curb (or other type of barrier) or by constructing a for quantifying benefits.) reinforced grass shoulder (see Fact Sheet T-10.5). Design Procedure and Criteria The following steps outline the grass buffer design procedure and criteria. Figure GB-1 is a schematic of the facility and its components: 1. Design Discharge: Use the hydrologic procedures described in the Runoff chapter of Volume 1 to determine the 2-year peak flow rate (QZ) of the area draining to the grass buffer. 2. Minimum Width: The width (W), normal to flow of the buffer, is typically the same as the contributing basin (see Figure GB-1). An exception to this is where flows become ' concentrated. Concentrated flows require a level spreader to distribute flows evenly across the width of the buffer. The minimum width should be: __ Q2 W 0.05 Equation GB-1 ■ Can easily be incorporated into a treatment train approach. ■ Provides green space available for multiple uses including recreation and snow storage. ■ Straightforward maintenance requirements when the buffer is protected from vehicular traffic. Limitations ■ Frequently damaged by vehicles when adjacent to roadways and unprotected. ■ A thick vegetative cover is needed for grass buffers to be effective. ■ Nutrient removal in grass buffers Where: is typically low. W = width of buffer (ft) ■ High loadings of coarse solids, Q2 = 2-year peak runoff (cfs) trash, and debris require pretreatment. 3. Length: The recommended length (L), the distance along ■ Space for grass buffers may not the sheet flow direction, should be a minimum of 14 feet. be available in ultra urban areas This value is based on the findings of Barrett et al. 2004 in (lot -line -to -lot -line). Stormwater Pollutant Removal in Roadside Vegetated Strips and is appropriate for buffers with greater than 80% vegetative cover and slopes up to 10%. The study found that pollutant removal continues throughout a length of 14 feet. Beyond this length, a point of diminishing returns in pollutant reduction was found. It is important to note that shorter lengths or slightly steeper slopes will also provide some level of removal where site constraints dictate the geometry of the buffer. GB-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 I MAPS AND DESIGNAIDS - URBANDRAINAGE GRASS BUFFER f Grass Buffer 4. Buffer Slope: The design slope of a grass buffer in the direction of flow should not exceed 10%. Generally, a minimum slope of 2% or more in turf is adequate to facilitate positive drainage. For slopes less than 2%, ' consider including an underdrain system to mitigate nuisance drainage. 5. Flow Characteristics (sheet or concentrated): Concentrated flows can occur when the width of the watershed differs from that of the grass buffer. Additionally, when the product of the watershed flow length and the interface slope (the slope of the watershed normal to flow at the grass buffer) exceeds approximately one, flows may become concentrated. Use the following equations to determine flow characteristics: Sheet Flow: FL(SI) <_ 1 Concentrated Flow: FL(SI) > 1 Where: FL = watershed flow length (ft) SI = interface slope (normal to flow) (ft/ft) T-1 Use of Grass Buffers Sheet flow of stormwater through a grassed area provides some benefit in pollutant removal and volume reduction even when the geometry of the BMP does not meet the criteria provided in this Fact Sheet. These criteria provide a design procedure that should be used when possible; however, when site constraints are limiting, this treatment concept is still encouraged. Equation G13-2 Equation GB-3 6. Flow Distribution: Flows delivered to a grass buffer must be sheet flows. Slotted or flush curbing, permeable pavements, or other devices can be used to spread flows. The grass buffer should have relatively consistent slopes to avoid concentrating flows within the buffer. A level spreader should be used when flows are concentrated. A level spreader can be a slotted drain designed to discharge flow through the slot as shown in Photo GB-2. It could be an exfiltration trench filled with gravel, which allows water to infiltrate prior to discharging over a level concrete or rock curb. There are many ways to design and construct a level spreader. They can also be used in series when the length of the buffer allows flows to re - concentrate. See Figure GB-2 for various level spreader sections. Photograph GB-2. This level spreader carries concentrated flows into a slotted pipe encased in concrete to distribute flows evenly to the grass buffer shown left in the photo. Photo courtesy of Bill Wenk. November 2010 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 GB-3 I MAPS AND DESIGNAIDS - URBAN DRAINAGE GRASS BUFFER i T-1 Grass Buffer Photos GB-3 and GB-4 show a level ' spreader that includes a basin for sedimentation. Concentrated flows enter the basin via stotmsewer. The basin is designed to drain slowly while overflow is spread evenly to the downstream vegetation. A small notch, orifice, or pipe can be used to drain the level spreader completely. The opening should be small to encourage frequent flows to overtop the level spreader but not so small that it is frequently clogged. 7. Soil Preparation: In order to encourage establishment and long- term health of the selected vegetation, it is essential that soil conditions be properly prepared prior to installation. Following site grading, poor soil conditions often exist. When possible, remove, strip, stockpile, and reuse on -site topsoil. If the site does not contain topsoil, the soils should be amended prior to vegetation. Typically 3 to 5 cubic yards of soil amendment (compost) per 1,000 square feet, tilled 6 inches into the soil is required in order for vegetation to thrive, as well as to enable infiltration of runoff. Additionally, inexpensive soil tests can be conducted to determine required soil amendments. (Some local governments may also require proof of soil amendment in landscaped areas for water conservation reasons.) Photograph GB-3. This level spreader includes the added benefit of a sedimentation basin prior to even distribution of concentrated flows from the roadway into the grass buffer. Photo courtesy of Bill Wenk. Photograph GB4. Maintenance access is provided via the ramp located at the end of the basin. Photo courtesy of Bill Wenk. 8. Vegetation: This is the most critical component for treatment within a grass buffer. Select durable, dense, and drought tolerant grasses to vegetate the buffer. Also consider the size of the watershed as larger watersheds will experience more frequent flows. The goal is to provide a dense mat of vegetative cover. Grass buffer performance falls off rapidly as the vegetation coverage declines below 80% (Barrett et al.2004). GB-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 MAPS AND DESIGNAIDS - URBAN DRAINAGE GRASS BUFFER Grass Buffer T-1 Turf grasses such as Kentucky bluegrass are often selected due to these qualities'. Dense native turf grasses may also be selected where a more natural look is desirable. Once established, these provide the benefit of lower irrigation requirements. See the Revegetation chapter in Volume 2 of this manual with regard to seed mix selection, planting and ground preparation. Depending on soils and anticipated flows, consider erosion control measures until vegetation has been established. 9. Irrigation: Grass buffers should be equipped with irrigation systems to promote establishment and survival in Colorado's semi -arid environment. Systems may be temporary or permanent, depending on the type of vegetation selected. Irrigation application rates and schedules should be developed and adjusted throughout the establishment and growing season to meet the needs of the selected plant species. Initially, native grasses require the same irrigation requirements as bluegrass. After the grass is established, irrigation requirements for native grasses can be reduced. Irrigation practices have a significant effect on the function of the grass buffer. Overwatering decreases the permeability of the soil, reducing the infiltration capacity and contributing to nuisance baseflows. Conversely, under watering may result in delays in establishment of the vegetation in the short term and unhealthy vegetation that provides less filtering and increased susceptibility to erosion and rilling over the long term. 10. Outflow Collection: Provide a means for downstream conveyance. A grass swale can be used for this purpose, providing additional LID benefits. Construction Considerations Success of grass buffers depends not only on a good design and long-term maintenance, but also on installing the facility in a manner that enables the BMP to function as designed. Construction considerations include: ■ The final grade of the buffer is critical. Oftentimes, following soil amendment and placement of sod, ' the final grade is too high to accept sheet flow. The buffer should be inspected prior to placement of seed or sod to ensure appropriate grading. ■ Perform soil amending, fine grading, and seeding only after tributary areas have been stabilized and utility work crossing the buffer has been completed. ■ When using sod tiles stagger the ends of the tiles to prevent the formation of channels along the joints. Use a roller on the sod to ensure there are no air pockets between the sod and soil. ■ Avoid over compaction of soils in the buffer area during construction to preserve infiltration capacities. ■ Erosion and sediment control measures on upgradient disturbed areas must be maintained to prevent excessive sediment loading to grass buffer. ' Although Kentucky bluegrass has relatively high irrigation requirements to maintain a lush, green aesthetic, it also withstands drought conditions by going dormant. Over -irrigation of Kentucky bluegrass is a common problem along the Colorado Front Range, and it can be healthy, although less lush, with much less irrigation than is typically applied. November 2010 Urban Drainage and Flood Control District G13-5 Urban Storm Drainage Criteria Manual Volume 3 MAPS AND DESIGNAIDS- URBANDRAINAGE GRASS BUFFER T-1 Grass Buffer Zo. 4 � JJ I W 1) "WATIER5REQ rLOW LENr,,Tk sm PLAN 7-1 I*T03" LIP WWIERE SUITABLE 0-1 10% 14: (M'VA 1E-AMtNDrD 50IL5� LEVEL SPREADER PROFILE Figure CB-1. Typical Crass Buffer Graphic by Adia Davis. Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 MAPS AND DESIGN AIDS - URBAN DRAINAGE GRASS BUFFER Grass Buffer T-1 CORRUGATED SLOTTED DRAIN PIPE GRASS BUFFER Lim AGGREGATE BASE COURSE SECTION r, LEVEL SPREADER FOR PIPE FLOWS PIPE AND HEADWALL BEYOND GRASS BUFFER` CURB ED DRAIN PAN WITH CURBS SECTION r. LEVEL SPREADER FOR PIPE FLOWS GRASS BUFFER An \' ` UNDERORAIN, SEE SECTION 5 (OR PROVIDE SMALL OPENING IN WALL) SECTION � LEVEL SPREADER FOR SURFACE FLOWS GRASS BUFFER �. M t UNDERDRAIN, SEE SECTION 5 (OPTIONAL) SECTION rn LEVEL SPREADER FOR SMALL SURFACE FLOWS CDOT CUSS C FILTER MATERIAL OR OTHER COMPATIBLE MATERIAL SUCH AS AASHTO #57 OR #67 CDOT VARIES, MIN 8" CLASS C FILTER 4, MATERIAL PER TABLE SLOTTED PIPE PER TABLE GS-3' GS-2' 1. SEE BMP FACT SHEET T-2, GRASS SWALE SECTION 0 UNDERDRAIN '' Figure GB-2. Typical Level Spreader Details November 2010 Urban Drainage and Flood Control District G13-7 Urban Storm Drainage Criteria Manual Volume 3 MAPS AND DESIGN AIDS URBAN DRAINAGE GRASS SWALE Grass Swale Description Grass swales are densely vegetated trapezoidal or triangular channels with low-pitched side slopes designed to convey runoff slowly. Grass swales have low longitudinal slopes and broad cross -sections that convey flow in a slow and shallow manner, thereby facilitating sedimentation and filtering (straining) while limiting erosion. Berms or check dams may be incorporated into grass swales to reduce velocities and encourage settling and infiltration. When using berms, an underdrain system should be provided. Grass swales are an integral part of the Low Impact Development (LID) concept and may be used as an alternative to a curb and gutter system. Site Selection T-2 Photograph GS-1. This grass Swale provides treatment of roadway runoff in a residential area. Photo courtesy of Bill Ruao. Grass swales are well suited for sites with low to moderate slopes. Drop structures or other features designed to provide the same function as a drop structures (e.g., a driveway with a stabilized grade differential at the downstream end) can be integrated into the design to enable use of this BMP at a broader range of site conditions. Grass swales provide conveyance so they can also be used to replace curb and gutter systems making them well suited for roadway projects. Designing for Maintenance Recommended ongoing maintenance practices for all BMPs are provided in Chapter 6 of this manual. During design, the following should be considered to ensure ease of maintenance over the long-term: Consider the use and function of other site features so that the swale fits into the landscape in a natural way. This can encourage upkeep of the area, which is particularly important in residential areas where a loss of aesthetics and/or function can lead to homeowners filling in and/or piping reaches of this BMP. Grass Swale Functions LID/Volume Red. Yes W CV Capture No WQCV+Flood Control No Fact Sheet Includes EURV Guidance No Typical Effectiveness for Targeted Pollutants3 Sediment/Solids Good Nutrients Moderate Total Metals Good Bacteria Poor Other Considerations Life -cycle Costs Low 'Based primarily on data from the International Stormwater BMP Database (www. bmodatabase. ore). November 2010 Urban Drainage and Flood Control District GS-I Urban Storm Drainage Criteria Manual Volume 3 ' MAPS AND DESIGN AIDS -URBAN DRAINAGE GRASS SWALE T-2 • Provide access to the swale for mowing equipment and design sideslopes flat enough for the safe operation of equipment. ■ Design and adjust the irrigation system (temporary or permanent) to provide appropriate water for the selected vegetation. ■ An underdrain system will reduce excessively wet areas, which can cause rutting and damage to the vegetation during mowing operations. ■ When using an underdrain, do not put a filter sock on the pipe. This is unnecessary and can cause the slots or perforations in the pipe to clog. Design Procedure and Criteria The following steps outline the design procedure and criteria for stormwater treatment in a grass swale. Figure GS-I shows trapezoidal and triangular swale configurations. Grass Swale Benefits ■ Removal of sediment and associated constituents through filtering (straining) ■ Reduces length of storm sewer systems in the upper portions of a watershed ■ Provides a less expensive and more attractive conveyance element • Reduces directly connected impervious area and can help reduce runoff volumes. Limitations ■ Requires more area than traditional storm sewers. I . Design Discharge: Determine the 2-year flow rate to be conveyed in the grass swale under fully developed • Underdrains are recommended for conditions. Use the hydrologic procedures described in slopes under 2%. the Runoff Chapter in Volume 1. • Erosion problems may occur if not 2. Hydraulic Residence Time: Increased hydraulic designed and constructed residence time in a grass swale improves water quality properly. treatment. Maximize the length of the Swale when possible. If the length of the swale is limited due to site constraints, the slope can also be decreased or the cross -sectional area increased to increase hydraulic residence time. 3. Longitudinal Slope: Establish a longitudinal slope that will meet Froude number, velocity, and depth criteria while ensuring that the grass swale maintains positive drainage. Positive drainage can be achieved with a minimum 2% longitudinal slope or by including an underdrain system (see step 8). Use drop structures as needed to accommodate site constraints. Provide for energy dissipation downstream of each drop when using drop structures. 4. Swale Geometry: Select geometry for the grass swale. The cross section should be either trapezoidal or triangular with side slopes not exceeding 4:1 (horizontal: vertical), preferably flatter. Increase the wetted area of the swale to reduce velocity. Lower velocities result in improved pollutant removal efficiency and greater volume reduction. If one or both sides of the grass swale are also to be used as a grass buffer, follow grass buffer criteria. GS-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 ' MAPS AND DESIGNAIDS - URBAN DRAINAGE GRASS SWALE Grass Swale T-2 5. Vegetation: Select durable, dense, and drought tolerant grasses. Turf grasses, such as Kentucky bluegrass, are often selected due to these qualities'. Native turf grasses may also be selected where a more natural look is desirable. This will also provide the benefit of lower irrigation requirements, once established. Turf grass is a general term for any grasses that will form a turf or mat as opposed to bunch grass, which will grow in clumplike fashion. Grass selection should consider both short-term (for establishment) and long-term maintenance requirements, given that some varieties have higher maintenance Native grasses provide requirements than others. Follow criteria in the a more natural aesthetic Revegetation Chapter of Volume 2, with regard to seed and require less water mix selection, planting, and ground preparation. once established. 6. Design Velocity: Maximum flow velocity in the Swale should not exceed one foot per second. Use the Soil Conservation Service (now the NRCS) vegetal retardance curves for the Manning coefficient (Chow 1959). Determining the retardance coefficient is an iterative process that the UD-BMP workbook automates. When starting the swale vegetation from sod, curve "D" (low retardance) should be used. When starting vegetation from seed, use the "E" curve (very low vegetal retardance). 7. Design Flow Depth: Maximum flow depth should not exceed one foot at the 2-year peak flow rate. Check the conditions for the 100-year flow to ensure that drainage is being handled without flooding critical areas, structures, or adjacent streets. Table GS-1. Grass Swale Design Summary for Water Quality Maximum Maximum Maximum Design Flow Froude Number Velocity Flow Depth 2-year event 0.5 1 ft/s 1 ft Use of Grass Swales Vegetated conveyance elements provide some benefit in pollutant removal and volume reduction even when the geometry of the BMP does not meet the criteria provided in this Fact Sheet. These criteria provide a design procedure that should be used when possible; however, when site constraints are limiting, vegetated conveyance elements designed for stability are still encouraged. ' 1 Although Kentucky bluegrass has relatively high irrigation requirements to maintain a lush, green aesthetic, it also withstands drought conditions by going dormant. Over -irrigation of Kentucky bluegrass is a common problem along the Colorado Front Range. It can be healthy, although less lush, with much less irrigation than is typically applied. !J November 2010 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 GS-3 ' MAPS AND DESIGN AIDS -URBAN DRAINAGE GRASS SWALE Fj I f 1 I I u I J [1 I I T-2 Grass Swale 8. Underdrain: An underdrain is necessary for swales with longitudinal slopes less than 2.0%. The underdrain can drain directly into an inlet box at the downstream end of the swale, daylight through the face of a grade control structure or continue below grade through several grade control structures as shown in Figure GS-l. The underdrain system should be placed within an aggregate layer. If no underdrain is required, this layer is not required. The aggregate layer should consist of an 8-inch thick layer of CDOT Class C filter material meeting the gradation in Table GS-2. Use of CDOT Class C Filter material with a slotted pipe that meets the slot dimensions provided in Table GS-3 will eliminate the need for geotextile fabrics. Previous versions of this manual detailed an underdrain system that consisted of a 3- to 4-inch perforated HDPE pipe in a one -foot trench section of AASHTO #67 coarse aggregate surrounded by geotextile fabric. If desired, this system continues to provide an acceptable altemative for use in grass swales. Selection of the pipe size may be a function of capacity or of maintenance equipment. Provide cleanouts at approximately 150 feet on center. Table GS-2. Gradation Specifications for Class C Filter Material (Source: CDOT Table 703-7) Sieve Size Mass Percent Passing Square Mesh Sieves 19.0 min (3/4") 100 4.75 mm (No. 4) 60 — 100 300 m (No. 50) 10 — 30 150 pm o. 100 0 — 10 75 4m (No. 200) 0-3 Table GS-3. Dimensions for Slotted Pipe Pipe Diameter Slot Length' Maximum Slot Width Slot Centers` Open Area' (per foot) ) 4" 1-1/16" 0.032" 0.413" 1.90 in 6" 1-3/8" 0.032" 0.516" 1.98 in' 'Some variation in these values is acceptable and is expected from various pipe manufacturers. Be aware that both increased slot length and decreased slot centers will be beneficial to hydraulics but detrimental to the structure of the pipe. GS4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 I MAPS AND DESIGN AIDS - URBAN DRAINAGE GRASS SWALE Grass Swale T-2 9. Soil preparation: Poor soil conditions often exist following site grading. When the section includes an underdrain, provide 4 inches of sandy loam at the invert of the swale extending up to the 2-year water surface elevation. This will improve infiltration and reduce ponding. For all sections, encourage establishment and long-term health of the bottom and side slope vegetation by properly preparing the soil. If the existing site provides a good layer of topsoil, this should be striped, stockpiled, and then replaced just prior to seeding or placing sod. If not available at the site, topsoil can be imported or the existing soil may be amended. Inexpensive soil tests can be performed following rough grading, to determine required soil amendments. Typically, 3 to 5 cubic yards of soil amendment per 1,000 square feet, tilled 4 to 6 inches into the soil is required in order for vegetation to thrive, as well as to enable infiltration of runoff. 10. Irrigation: Grass swales should be equipped with irrigation systems to promote establishment and survival in Colorado's semi -arid environment. Systems may be temporary or permanent, depending ' on the type of grass selected. Irrigation practices have a significant effect on the function of the grass swale. Overwatering decreases the permeability of the soil, reducing the infiltration capacity of the soil and contributing to nuisance baseflows. Conversely, under watering may result in delays in establishment of the vegetation in the short term and unhealthy vegetation that provides less filtering (straining) and increased susceptibility to erosion and riling over the longterm. Construction Considerations Success of grass swales depends not only on a good design and maintenance, but also on construction N O practices that enable the BMP to function as designed. I Construction considerations include: PARKING ■ Perform fine grading, soil amendment, and seeding �{ O 1 �1 only after upgradient surfaces have been stabilized and utility work crossing the swale has been 1A1 completed. S 11 P A L E I■ Avoid compaction of soils to preserve infiltration capacities. ■ Provide irrigation appropriate to the grass type. ■ Weed the area during the establishment of vegetation Photograph CS-2. This community used by hand or mowing. Mechanical weed control is signage to mitigate compaction of soils post - preferred over chemical weed killer. construction. Photo courtesy of Nancy Styles. ■ Protect the swale from other construction activities. ■ When using an underdrain, ensure no filter sock is placed on the pipe. This is unnecessary and can cause the slots or perforations in the pipe to clog. November 2010 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 GS-5 February 3, 2015 The CPI Group 7400 East Orchard Road, Suite 270 Greenwood Village, Colorado 80111 Attn: Mr. Michael Bello P: (970) 288-5477 E: michael.bello@thecpigroup.net Re: Groundwater Measurements Avago Building 3 Detention Ponds 4380 Ziegler Road Fort Collins, Colorado Terracon Project No. 20145068 Dear Mr. Bello: Irerracon Previously, Terracon Consultants, Inc. (Terracon) prepared a Geotechnical Engineering Report (Project No. 20145068; revised report dated January 27, 2015) for this project. At your request, Terracon completed the installation of three (3) temporary piezometers at the project site referenced above. The temporary piezometers were installed in areas of the site where the project team is considering storm water detention ponds as shown on the attached Exploration Plan (Figure 1). We have also attached logs of the boreholes used to complete as temporary piezometers as Figures 2 through 4. We completed the temporary piezometers on Friday, January 30, 2015 and returned to the site on Tuesday, February 3, 2015 to measure groundwater levels within each of the three piezometers. The measured depths to groundwater from existing site grades and corresponding groundwater elevations are summarized in the table below. Date Measured Temporary Piezometer Number - --- - --- 8 9 —1 0 Depth to Groundwater (ft.) 6.6 5.6 20.4 2/3/15 Elevation of Groundwater (ft.) 4907.7 4908.2 4902.5 Terracon Consultants, Inc. 1901 Sharp Point Drive, Suite C Fort Collins, Colorado 80525 P [970] 484-0359 F [970] 484-0454 www,terracon.com Groundwater Measurements 1 �erraeon Avago Building 3 Detention Ponds n Fort Collins, Colorado February 3, 2015 . Terracon Project No. 20145068 We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this letter, or if we ma a of further service, please contact us. Sincerely, A� �R tZ, Terracon 31/S 8829 �? r Eric D. Bernhardt, P.E. Geotechnical Department �c 6 J2. Attachments: Figure 1 — Exploration Plan Figure Nos. 2 through 4 — Boring Logs Copies to: Client (via e-mail) 1,a F.ez�ourceful RFliabl�-: Bryce C. Reeves, E.I. Geotechnical Engineer I I 1 I I I I I I I DIAGRAM IS FOR GENERAL LOCATION ONLY. AND IS AERIAL PHOTOGRAPHY PROVIDED NOT INTENDED FOR CONSTRUCTION PURPOSES BY MICROSOFT BING MAPS Prolact Manager. Project No. EDB 20145068 1 ��rracon 1901 Sharp Point or Suite C Ft. Collins, CO 80626 EXPLORATION PLAN Avago Building 3 4380 Ziegler Rd Fort Collins, CO Figure Drawn by. BCR �A SHOWN ,) Checked by: EDB File Name: Approved by: EDB Date: 2/3/2015 I I I I I r, i I I I I I BORING LOG NO. 8 Pa e 1 of 1 PROJECT: Avago Building 3 CLIENT: The CPI Group Greenwood Village, Colorado SITE: 4380 Ziegler Road Fort Collins, Colorado a LOCATION See Exhibit A-2 w a A ER LIMITS y Z LL Lu m y t 4 Latitude: 40.525197" Longitude:-105.018935' a Lu w F w f w w 3 i X W LL-PL-PI u O Surface Elev.; 4914.3 (FL) o a m O 3 DEPTH ELEVATION F LAND APE RA - in h SANDY LEAN CLAY (CLI, reddish -brown, medium stiff to stiff 5-5 17 107 5 4-5 22 97 35-19-16 57 6.0 4908.5 WE WELL GRADED SAND WITH SILT AND GRAVEL, fine to coarse grained, brown, medium dense $ 1 -1a9 15 to.s 4904 Boring Terminated at 10.5 Feet Stratification lines are approximate. In -situ, the transition may be gradual. Hammer Type: Automatic Advancement Method: See Exhibit A-3 for description of field Notes: 4 inch solid -stem augers procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and Abandonment Method: Bonngs backfilled with soil cuttings upon completion. abbreviations. WATER LEVEL OBSERVATIONS Irerracon 1901 Sham Point Drive, Suite C Boring Started: 1212312014 Boring Completed: 12/2312014 �Z While Drilling Ddll Rig: CME-55 Dollar. Unlimited Access Dulling Figure 2 1117114 Fort Collins, Colorado jProl No.: 20145068 I I U 1 1 1 1 i 1 1 I I I 1 1j 1 BORING LOG NO. 9 Page 1 of 1 PROJECT: Avago Building 3 CLIENT: The CPI Group Greenwood Village, Colorado SITE: 4380 Ziegler Road Fort Collins, Colorado LOCATION See Exhibit A-2 w � ATTIMIIBIERG w O LatiWde: 40.524845° Longitude. -105.018781" .., _ �< a � elN Hw-� � w� H �F z F w w w 3 z. a LL-PL-PI v Surface Elev.: 4913.8 (FL) 0 Q w w 3m O er DEPTH ELEVATION FL n D APE RA - in h SANDY LEAN CLAY (CU, brown to reddish -brown, stiff 5 s 5 21 107 6.0 4908 WELL GRADED SAND WITH SILT AND GRAVEL, fine to coarse grained, brown, medium dense 9-10.5 9.0 4905 WEATHERED SEDIMENTARY BEDROCK -CLAYSTONE, olive 4$10 24 aso3.s 1 N=18 Boring Terminated at 10.5 Feet Stratificabon lines are approximate. In -situ, the transition may be gradual. Hammer Type: Automatic Advancement Method: See Exhibit A-3 for description of field Notes: 4 inch solid -stem augers procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and Abandonment Method. Bonngs bankfilled with sal cuttings upon completion. abbreviations. WATER LEVEL OBSERVATIONS Irerracon.01/17/14 1901 Sham Pant Drive, Suite C Boring Started: 12123/2014 Boring Completed: 12/23/2014 MjieDnlfi� Rig: CMEbS Driller. Unlimited Access Drilling Figure 3 Fort Collins. Colorado Project No.: 20145068 g 1 I I I 1 I 1 I I I I t BORING LOG NO. 10 Page 1 of 1 PROJECT: Avago Building 3 CLIENT: The CPI Group Greenwood Village, Colorado SITE: 4380 Ziegler Road Fort Collins, Colorado Co o = o_ LOCATION see Exhibit A-z Latitude. 40.528692" Longitude.-105.018683' v.: Surface Ele4922.9 (FL) DEPTH ELEVATION(Ft.)30 ^, _ w O w= a 0. J a At,� rn F top O� w w w ~ 3 i O O -- ~ 2 tr 3 ATTERBERLIMITS w v o. LL-PL-PI LEAN CLAY WITH SAND, dark brown to brown, medium stiff 5 3-3-3 N=6 20 - 7.0 4916 SANDY LEAN CLAY, light brown, medium stiff j1 Arm, - 2-3-2 N=5 11 414,5 4908.5 2-3-3 Nam, 13 CLAYEY SAND. fine to medium grained, reddish -brown, loose 18.0 4905 WELL GRADED SAND WITH SILT, fine to coarse grained, reddish -brown. medium dense 2 17 6-8-3 N=11 27 22.0 4901 Boring Terminated at 22 Feet Stratification lines are approximate. In-situthe transdlon may be gradual. Hammer Type: Automatic Advancement Method: 4 inch solid -stem augers See Exhibit A-3 for descriptor of field procedures. Notes: See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and Abandonment Method: Boring converted to temporary piezometer upon abbreviations. completion WATER LEVEL OBSERVATIONS Irerracon 1901 Sharp Point Drive, Suite C Fort Collins, Colorado Boring Started: 1/29/2015 Boring Completed: 1/29/2015 While on„ing Drill Rig: CME45 Driller. Unlimited Access Drilling �15 Project No.; 20145088 Figure 4 '1, I 1 HYDROLOGIC COMPUTATIONS f RATIONAL METHOD I i PROJECT INFORMATION PROJECT NAME: AVAGO 83 PROJECT NO: 14.033 DESIGN BY: RJS REVIEWED BY: PSB JURISDICTION: FORT COONS REPORT TYPE: DATE: (ON5115 MARTIN /MARTIN ��i/� co.�ui�l.o v..a�.ea�• JUPoSgCTIONALSTANg1R0 C2 CS CID C100 %IMPERV LANDSCAPE 0.1p1 0.10 1 0.10 0.13 0% RCOF 0.95 OAS 0.95I Im 90% DRIVES AMVIMLKS 0.95 0.95 0.95 1.00 90% POROUS PAVERS 1 0.50 0.50 0.50 0,67 40% TOTAL SITE COMPOSITE I 20.21 I 0A8 I Om OM 0.00 SUB -BASIN SURFACE CHARACTERISTICS AREA COMPOSITE RUNOFF COEFFICIENTS PERCENT IMPERVIOUSNESS (ACRES) C2 CS CID C100 LANDSCAPE 8.15 0.10 0.10 0.10 0.13 O% Al ROOF moo 0.95 0.95 0.05 1.00 90% DRIVES AND WALKS 1.54 0.95 0.05 0.86 1.00 90% POROUS PAVERS 0.48 0.50 0.50 0.50 0.83 /014 SUB -BASIN COMPOSITE 0.16 0.20 0.28 Q29 0.32 I 10.4% SUB -BASIN SURFACE CHARACTERSTIC6 [LANDSCAPE AZ ROOF AREA COMPOSITE RUNOFF COEFFICIENTS PERCENT IMPERVIOUSNESS (ACRES) C2 CS CID CI00 0.20 DAD 0.10 0.10 0.13 0% 0.00 0.95 0.96 0.95 1.O 90% DRIVES ANCWALKS 0.21 0.05 0.95. 0.05 1.00 9094 POROUS PAVERS 0.00 0.50 0.50 0.50 0.0 40% SUSBASIN COMPOSITE 1.11 040 0.60 OJM 0.114 73.7% SUBBASIN SURFACE CHARACTERISTICS AREl1 (ACRES) COMROSITE RUNOFF COEFFICIENTS PERCENT IMPERVIOUSNESS C2 DO CID CIm 1.42 OAD D.10 o.1n a17 0% B� ROOF Dm 0.95 OAS OAS 1.00 90% URIVES ANC[ WALKS 1.75 0.05 0.95 0.95 1.00 90% POROUS PAVERS 0.00 0.50 0.50 0.50 0.63 40A SUSBa51N COMPOSITE 117 0A7 0.9 I Om I 491 I 41111.7% SUBBASIN SURFACE CHARACTERISTICS AREA OEFFlpENT3 COMPOSITE RUNOFF C PERCENT IMPERVIOUSNESS (ACRES) C2 CS CIO CIO LANDSCAPE 0.56 1.10 0.10 0.10 0.13 0% BZ ROOF L20 0.95. D.95 OAS 1.00 00% DRIVE5 AND WALKS 0.38 0.95 0.05 0.95 1.00 90% POROUS PAVERS 0.20 0.60 0.50 0.50 0.53 40% SUBBASIN COMPOSITE 150 0.87 QS7 8.67 0.73 60.3% SUB -BASIN SURFACE CHARACTERISTICS AREA COMPOSITE RUNOFF COEFFICIENTS PERCENT IMPERVIOUSNESS (ACRES) C2 CS C10 C100 C' LANDSCAPE ROOF _ DRIVES AND WALKS 4.78 0.10 0.10 0.95 OA5 0.10 a13 a% 0.00 0.05 0.05 _0.05 0.95 1.00 1.00 00% 90% 2.83 POROUS PAVERS 0.32 0.50 0.50 1 0.50 0.83 401L SUEBASw COMPOSITE 1 7.03 0.0 OA2 I OA2 1 0.K 1 ON SUB -BASIN SURFACE CHARACTERISTICS AREA COMPOSITE RUNOFF COEFRCIENTE PERCENT IN (ACRES) C2 CS CIO C700 LANDSCAPE 0.43 0.10 0.10 0.70 0,13 0% D� ROOF 0.11 OAS N 0.95 1.00 90% DRIVES AND WALKS 0." 0.05 O.BS O 1.00 90% POROUS PAVERS OAO 0.50 0.50 0.AS SO O.B3 40% SLABASWCOMPOSITE 1.07 1 0.59 1 0.59 1 0.36 0.W. 52.1% SUB -BASIN ' SURFACE CHARACTERISTICS AREA COMPOSITE RUNOFF COEFNCIENTB PERCENT IMPERVIOUSNESO (ACRES) C2 CS CIO C100 LANDSCAPE 1.18 DID 0.10 0.10 0.13 0% DY ROOF DOD 0.05 0.85 pA5 1.00 A DRIVES AND WALKS 1.18 OAS 0.05 0.95 1.00 9p% POROUS PAVERS OAD 0.50 0.50 0.50 0.63 40% 3UBBA304 COMPOSITE 2.36 OA3 (I13 0.52 QN µA% SUBBAWN SURFACE CHARACTERISTICS ARE11 COMPOSITE RUNOFF COEFFICIENTS PERCENT IMPERVIOUSNESS (ACRES[ C2 CS CIO C100 LANDSCAPE 0.05 0.10 0.10 0.10 0:13 0% D3 ROOF 0.14 0.85 0.95 0.95 1.00 W% DRIVES ANDwALKs 0.51 o.as oAs 0.95 t00 90% POROUS PAVERS 0.00 0.50 0.50 0.50 OA3 40% SUB -BASIN COMPOSITE 0.70 0.89 OA9 0.p am I 93.5% SUB43ASIN SURFACE CHARACTERISTICS AREA COMPOSITE RUNOFF COEFFICIENTS PERCENT IMPERVIOUSNESS (ACRE91 C2 CS CIO C100. LANDSCAPE o.7o D.10 0.10 a10 pA3 a% ROOF 0.00 0.0.5 0.95 0.96 1.00 00% DRIVES AMC WALKS 0.49 D.95 0.95 OAS 1.D0 9D% POROUS PAVERS 0.00 OSO 0.50 O:s0 0" 40% SUBBASIN COMPOSITE 1.19 OAS OAS 0.45 OAS 37.1% TOTAL SITE COMPOSITE 25.21 OAG OAS I O.K OA0 COMPOSITE C-VALUES 3)5/ 15:1 35 PM G:ISCHLAGETER%14.0831Avago-Buit6mg31ENGURNNAGEWa9onal CMmQQt50313THIRO SUBMITTAL RATIONAL. tlem Y a W J Zy c y O O O O O O O O O LL Z C f O O O O O O O O O m 2 Y � U m m � c o 0 0 0 0 0 0 0 0 U y 0 0 0 0 0 0 0 0 0 z o a 0 f n o 0 0 0 0 0 0 0 0 _y p ,_ 0 0 0 0 0 0 0 0 0 U p O O O O O O O C O O O O O O O O O O J b O O O O O O O O O O 0 W O O o 0 o 0 0 I, 0 F- U m j a i r a p � m m r I Z r n w i E o 0 0 0 0 0 0 0 0 a 0 0 0 0 0 0 0 0 ❑ g � 3 w LT O 2 _ OJ c � r N a F r Z s v w J a w u m uNi m o n O1 Q ry ry l0 N !� t0 N Y m N tV 0 O Z (J 0 0 0 O O O O O O <a a r m o Z N m p <¢ m m 0 0 0 0 0 oa Z Q m �VV 0 0 0 m U p i1c, U c 0 m U m c i. m 'c U N N 1� o n H m u a x � v m L aim w m u n `3 f mo a mm v a O T O L T y°j D m p 0 Ob N ry r = F (g0 z (7 a N i inN O K a o } in m Y w W au r LL Z O — z 7 a' 0 U o Q Q LL m m O m r N m Y 1� O U `� m M YI O Oi � ni � a - x n m r m r m r m r m r m r m r m r m r Z ` Cl N M N lV lV C! fV N Q m m m m m m z U W LL LL T OLL O m N a m r r N m N m N N N m m N W j O U O o 6 o V 0 0 0 O G m Q Z O a_ Z N Q Q m m U❑ 0 0 0 O w W ❑ Z Q¢ m a O a❑ i Co U m O u U a W Z Z 9 z z 'y m 0 b m LO C O x i Y m 5 > a a C b o c � o v c o [I w C ) � a U 5 s 3 f = E N c m a l<Id a O f a Z U p� oa°w R N 4 IL CD x N W_ ❑ Y w w Q U N ILLi. Z Z z 7 LL' Q O U o r Q in Q m OR 0 0 h 0 O aD m to m G Ol a7 h U O O aC m N !•1 N Cl lV a N m N N ly x U b m I� li 10 f(O O LL❑ U¢ N O t7 O O z U W o a ^ `+ YI YI M 1A h YI YI N YI LL LL 0 m O I� r N Of N Ol N WLL Q N oD YI IC Q v1 U( oD Q O U O O O O O O O O G � Q a � "' GC Cl u� fV m ih o n N r C r Z LL Z N Q N^ Q m N m U❑ N 0❑❑ Q 0 55 W Z_ 4 m mN U❑ O O Q m m A U 3 c U Q IaIbINI m W p w -, 0:v, a IL Z a CD W CA W z O O Z W m w N W 7 � w W W O w in w W Q O W rc m a W o -Z f co) Z rc F O N c, m O 0: 0_ o m co c w W K Q U N IWi 2 O — Z 7 J F U o Q O LL m n o n o11 ry m a N CI Z of ai ai of of ai of of of g N m N N N m m LLU Q e N C7 O m m t7 CO C n m O N G O Z 7 K U W ❑ Z N O O o 0 0 0 0 0 0 "y � N N N N N L61,6 N N LL W O W w a N n y m m r V m N0 m a j o o a;c o 0 0 0 0 U d' I:SEN� Z O IL N a Q m m U❑❑❑❑ Mn W O _Z m _ `. Q Q m m U❑ m u PROJECT: AVAGO B3 JOB NO: 01/14/00 DATE: 03/05/15 MARTIN /MARTIN CONSULTING ENGINEERS RUNOFF SUMMARY BASIN DESIGN POINT AREA (ACRES) % IMP. C10 Cloo Q10 (CFS) Q100 (CFS) Al Al 8.18 19.4% 0.28 0.32 10.87 25.39 A2 A2 1.11 73.7% 0.80 0.84 4.20 9.01 B1 B1 3.17 49.7% 0.57 0.61 8.59 18.78 B2 B2 2.55 60.3% 0.67 0.73 8.10 18.02 C1 C1 7.93 33.8% 0.42 0.46 15.81 35.38 D1 D1 1.03 52.1% 0.59 0.63 2.88 6.28 D2 D2 2.36 44.8% 0.52 0.56 5.83 12.82 D3 D3 0.70 83.6% 0.89 0.94 2.98 6.42 D4 D4 1.19 37.1 % 1 0.45 1 0.49 1 2.53 1 5.64 SITE COMPOSITE 28.21 38.3% 1 0.46 1 0.50 RUNOFF SUMMARY 3/5/2015 12:35 PM G:\SCHLAGETER\14.0833-Avago - Building 3\ENG\DRAINAGE\Rational Calcs\2015.03.13_THIRD SUBMITTAL RATIONAL.Asm I 1 1 1 1 1 1 1 1 1 i 1 i 1 1 1 1 1 HYDRAULIC COMPUTATIONS i f' 11 i I i i t 1 d H i i I 11 i i i \4 W Z J F— U) 1 1 1 1 1 r Im W_ S W a N 4 I 3 y Q N � � Q tC M SO 4-r my � N r• O M C O �E, CL U Es �r CL 41 J L d O` H M O C E � — � o y � nU U O o c 00 @j o �T O y U r• 0 U O O F LO � V m v .c wW W ._ W (4)U014en813 It 0 N 3 N N a+ Cl) 00 vi N O? 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Q r n N 7 N N O O! r. t+f W n n n t+1 rl VI m ON 0) COA O1 Orl rl N O1 l mOl V� V� v v v ? v O .-1 7 'O O N N N N Al (rl m S S S 2 S S S 1+1 Vl r• 00 N lA m 0 m01 =o v�m w aca w8 J W t/1 N NW U'm 00 5v 0 P I I r I 1_1 I WATER QUALITYDESIGN CALCULATIONS EXISTING IMPERVIOUS AREA ANALYSIS EXHIBIT PROPOSED IMPERVIOUS AREA ANALYSIS EXHIBIT STORAGE CALCULATIONS, MODIFIED FFA METHOD (NOT USED, FOR REFERENCE ONL 19 STORAGE CALCULATIONS, V KA METHOD WATER QUALITY CONTROL VOLUME CALCULATIONS POND STAGE STORAGE CALCULATIONS WQ ORIFICE PLATE CALCULATIONS EMERGENCY OVERFLOW WEIR CALCULATIONS LID, PROPOSED PAVEMENT AREA ANALYSIS EXHIBIT LID, PROVIDED POROUS PAVEMENT AREA ANALYSIS EXHIBIT LID, POROUS PAVEMENT RUN-ON AREA EXHBIT LID, LID TABLE I I I LJ 1 11 I NORTH 412,630 SF DRIVES/WALKS= 25,049 SF (0.58 AC) @ 90% IMP. = 0.52 AC ROOF= 0 SF (0 AC) @ 90% IMP. = 0 AC LANDSCAPE= 387,581 SF (8.90 AC) @ 0% IMP. = OAC NET IMPERVIOUS ACRES= 22,651 SF (0.52 AC (NET EXIST. % IMP.= 22,651/412,630=5.49%) SOUTH 656.570 SF DRIVES/WALKS= 228,006 SF (5.23 AC) @ 90% IMP. = 4.70 AC ROOF= 10,531 SF (0.24 AC) @ 90% IMP. = 0.22 AC LANDSCAPE= 418,033 SF (9.60 AC) @ 0% IMP. = 0 AC EXISTING IMPERVIOUS AREA ANAL YSIS EXHIBIT FOR USE IN DETERMINING THE ADDED IMPERVIOUS AREA FOR THE B3 DEVELOPMENT -i I AS OF THE PUBLISH DATE OF THIS REPORT, PAVEMENT POST -DEVELOPMENT EXISTS IN THIS AREA KEY MAP NORTH AREA L HIGHLIGHTED; HOWEVER, THIS PAVEMENT WAS TO BE REMOVED FOR THE B4 WEST ANNEX PROJECT IN ORDER TO ACHIEVE HYDROLOGIC DRIVES/WALKS COMPLIANCE WITH THE MASTER REPORT. THEREFORE, FOR THE � ROOF PURPOSES OF THE CURRENT ANALYSIS, THIS AREA IS CONSIDERED LANDSCAPE AREA. THIS CONSIDERATION i!\/\l,/i SERVES TO INCREASE THEREQUIRED STORAGE III FOR THE B3 PROJE TVOLUME L. L� o \1\T\\\ CCR\ \\\\\\\\\\\\\\\\ NET IMPERVIOUS ACRES= 214,315 SF (4.92 AC) (NET EXIST. % IMP.= 214,315/656,570=32.64%) 1 F ��2 C, I POST -DEVELOPMENT SOUTH AREA it I I, OVERALL DRIVES/WALKS= 253,055 SF (5.81 AC) @ 90% IMP. = 5.22 AC ROOF= 10,531 SF (0.24 AC) @ 90% IMP. = 0.22 AC LANDSCAPE= 805,614 SF (18.49 AC) @ 0% IMP. = 0 AC NET IMPERVIOUS ACRES= 5.44 AC MARTIN/MARTIN CONSULTING ENGINEERS 12499 WEST COLFAX AVENUE, LAKEWOOD, COLORADO 80215 303.431.6100 MARTIN MARTI N.COM NORTH 412.630 SF DRIVES/WALKS= 67,786 SF (1.56 AC) 0 90% IMP.= 1.40 AC POROUS PAVERS= 22,639 SF (0.52 AC) ® 40% IMP.= 0.21 AC ROOF= 0 SF (0 AC) ® 90% IMP.=O AC LANDSCAPE= 322,205 Sr (7.40 AC) ® 0% IMP.= 0 AC NET IMPERVIOUS ACRES= 70,132 SF (1.61 AC) (NET EXIST. % IMP.= 70,132/412,630=17.00%) I NORTH PRE —DEVELOPMENT NET IMPERVIOUS ACRES = 0.52 AC POST DEVELOPMENT NET IMPERVIOUS ACRES = 1.61 AC NET = +1.09 AC REQ'D DET. VOLUME = 0.242 (AC —FT) SOUTH 656.570 SF DRIVES/WALKS= 225,564 SF (5.18 AC) ® 90% IMP. = 4.66 AC POROUS PAVERS= 29,045 SF (0.67 AC) ® 40% IMP. = 0.27 AC ROOF= 74,917 SF (1.72 AC) ® 90% IMP. = 1.55 AC LANDSCAPE= 327,044 SF (7.51 AC) ® 0% IMP. = 0 AC NET IMPERVIOUS ACRES= 282,269 SF (6.48 AC) (NET EXIST. % IMP.= 282,269/656,570=42.99%) SOUTH PRE —DEVELOPMENT NET IMPERVIOUS ACRES = 4.92 AC POST DEVELOPMENT NET IMPERVIOUS ACRES = 6.48 AC NET = +1.56 AC REQ'D DET. VOLUME = 0.346 (AC —FT) POST —DEVELOPMENT NORTH AREA PROPOSED IMPERVIOUS AREA ANALYSIS EXHIBIT FOR USE IN DETERAHNING THE ADDED IMPERVIOUS AREA FOR THE B3 DEVELOPMENT i oaao� u KEY MAP DRIVES/WALKS — ROOF POROUS PAVERS OVERALL 1,069,200 SF SF (6.74 AC) DRIVES/WALKS= 293,350 \ ® 90% IMP. = 6.06 AC POROUS PAVERS= 51,684 SF (1.19 AC) ® 40% IMP. = 0.48 AC ROOF= 74,917 SF (1.72 AC) ® 90% IMP. = 1.55 AC LANDSCAPE= 649,249 SF (14.91 AC) ® 0% IMP. = 0 AC NET IMPERVIOUS ACRES= 8.09 AC DETENTION VOLUME BY THE MODIFIED FAA METHOD Project: Avago B3 Basin ID: NORTH EXISTING (For Catchnalnb lose Man 160 acme only. For larger catchmmnb, use hydrogbph routing method) (NOTE for catchments larger than 90 acres, CUHP hydrograph and routing are recolmendodj Determnation of "MJOR Detention Volulm Using Modified FAA Method I Dotermination of MAJOR Detention Volurlm Using Modified FAA Mebod RM1merrt Orvma9e Impernvuaneea :anmem omme,e Area PredevNppmere MRCS Sol Group R.. Period ror Oeteneon Comm Time 0 CmcerNagam Of Waterston Allowable thin Release Ram Cki".ur Pmcen e- DaaIoM "OFFo,mum I•C; P,IIC0TJ•Cr CDAIDClem ore Caanicrem Two C..ffciem Tire. l.- SAS Damon( A= O4)3 Type= C A, 8, C,.,D T= f0 yeas(2, 5, 10.25, 50, Or 100) Tc = 5 minNea g = 0.30 cfelsre P, = 400 inches c,= o c,= O2ap C.hmem Dmku,.Impamaunmm Coachmen Dmnse Area Pmd.v I.pmerei MRCS Sall Group Redlm P.n.d for Dmomme Cemol Time of Cpncenbrgi Pf WM.mhed Agoweble iAaa R.I... Ran, Oneulvur PrecipnWon Dealyn RalnmalOFFofeaula I•C; P,l(Cs T,YCe coeffiuem one Caeffiremi Two Caef Buss Three 1.= SAS Parent A- 0473 edw Type= c A, S,C.or0 T= t00 yep(2,5,10,25, W. or 100) Tc= 5 tomes A= 1.ao dwarfs P, = 288 Imhm C. • 28.50 C,= 10 C,= 0.759 Run.fl Coemcienr C= 0.28 Runoff Coefl .rt C= 0.52 Inflow Peak Runoff Op,n= 12.49 cis Inflow Peak RunOn Opin= 4740 _ cM Moweble PEA ONfl.w R. Opeu1= 2.04 cis Abnegate Peak Dumpvw RMe 0"EA= 2,47 et, M.d. FMMlnor Storage Vdume• 1665 cub1c had Mod. FM Maier Storage Volume- _ 32.130 Wm Mt M od. F AA M inor Storage Vdume• DID, echo-(( Mod. FM Major Storage Volu1M• O.T33 an'" Rada1 Rams Imo. AaBaonem AVwa,. OMOow SEW. mp Rwrid R/d w hi00w Ams"E 4 Averse owme S.W. Dl.ron lownery VAm. F.. oullow Volume Volume Ohio. ua.nMly Vokim. Factor ONnow VA. Value. mxulee vcMCIM xrNeM m cm wom4tel sweet mvMeA i.he.lm acre4eM m on, ame4W e pM le (OusueN N m u m m ul ul N N a 0.00 0.000o0.00 0.00 I GOOD 0.000 a 0,00 O.00D 0.00 0.00 0.000 0.000 5 4.71 Does 1.00 _ 2.84 0.020 Dan 5 9,62 0320 1.00 947 0.065 0.261 ID 3,75 0.137 1115 2.13 0.029 O.1 DO 10 ],6) 0.520 0.75 ).A0 0.090 OA22 5 3AS 0.173 0.57 1.99 0.039 0.133 15 a43 0.054 0.87 6.32 0.130 0.524 20 273 OJOS 063 170 0,049 0150 20 5.57 07513 0.63 592 0163 o,s03 25 Ut 0320 0.80 121 3058 0.182 25 4.93 0.8]e pO0 5.68 0.138 0.41 3a 2.17 0.2M O58 1.as 0.059 0.1)0 30 444 0.903 058 5.53 0128 a.675 35 1141 D253 0.57 162 0078 0.1)5 35 404 Dean 0.59 541 Dial n.o$ 40 do 0.258 0.58 1.60 OOa9 0.1)8 40 3.)2 1.010 0.56 5,33 024 0318 .5 +.w 0278 0.56 1.55 0.008 0.1SO 45 3,45 1.054 0.56 526 0.326 012e 50 1.58 0260 0.55 1.58 0.108 0.101 50 3.22 1.093 0.55 521 0,359 0335 55 1.48 0.298 0.55 1.55 0.117 0.100 55 3.03 1.129 O.SS 5.17 0.391 0135 00 1.40 0, ISO 0.54 to 0127 0.179 80 2.85 1.1W 0.54 5_.13 0A24 0.730 65 1.32 0314 0.54 1,53 0137 a'," 65 2.70 1.192 0.54 5.10 0.457 0.735 70 135 0.322 0.54 1.52 0.147 D.175 In 2.57 1.220 0.54 5.07 0489 75 +20 _ 0.329 053 152 0.157 0.172 75 2.45 1.248 0,53 5,05 0.522 _0.731 0.724 W IAS 01335 0.53 is, D,66 0,188 SO 2.34 1.2]0 0.53 5,03 0.555 0.71a a5 1 to O.3A+ 0,53 1.so 0,176 0, 105 85 214 1.293 0.53 5O2 0.587 0.705 90 1,05 OUII 0.53 1SO 0,185 0,101 90 2.15 1315 T53 5.00 0,620 0805 95 1.01 0.352 053 1.so 0,19E 0.159 95 2.07 1.336 003 _ _ 4.99 01852 0.683 100 GAS 0357 0.53 _ 1.49 0206 0.152 100 2,00 1356 _ aS3 497 0.585 0.870 105 a94 0352 0.52 1.49 0.215 0,147 105 1.03 1,374 0,52 _ LM 0.71e 0.657 110 0.01 0.387 D52 1.49 0.225 0.142 in 1.07 1392 0,52 4.95 0.750 0.642 115 Gas 0.371 OSS 1.48 0.235 0,137 115 'All 1.409 0.52 4.94 0.783 DAM 120 ODDS 0.376 0.52 IA9 0145 0131 120 1.75 1A25 0.52 4.03 0.616 0.610 125 083 0.380 0,52 148 0.254 OAM 125 1.]0 1412 as2 4.93 O.a48 0.593 tan O.a1 03e4 0.52 1.48 D.x4 SAID 130 ISO 1,457 Os2 4.e2 0.88, - 1570 135 0.797 0O9e 0.52 1A7 OV4 0.114 135 1.61 1Al2 om 4.81 0.913 05511 140 a." 0-392 0.52 147 T284 0.109 140 1.56 1480 _ 0,52 431 0.48 0.54 145 0T5_ 0.395 D.52 147 0.291 i1.102 145 1.52 1.500 0.52 4 90 0B78 0.521 15D 0.73_ 0.399 0.52 147 0,303 0.095 ISO 1.49 1.513 0.52 4.69 1011 0.502 155 0.71 0.402 0.52 147 0.313 0,000 155 145 1529 0.52 4.89 1.044 O412 ,so Data- 0405 0.52 147 D.323 0.083 160 142 _ 1.538 ass 1.58 1.07a 0492 185 0.86 0.4M 0.52 _ I4d 03]] 0.070 165 1.39 1.55, 052 ASS III. OM1 170 0.95 0412 051 146 0.343 0.089 170 1.35 1,562 0,51 4.88 1.142 0,421 175 am 0415 0.51 146 0.352 o.m3 175 133 1.574 0,51 437 1.1). 0400 ,so 0" DAIS as, +A9 0.362 0059 ISO 1.30 1.535 0.51 4.87 1207 0378 %as 0,82 0.421 0.51 146 03R 0049 185 12] 1.596 0.51 4,86 12AO 0357 ISO 0.61 GAZA os, 146 0.382 0.042 ISO 125 1,607 0.51 1.fifi 1272 0.335 195 0.60 oA28 osl 1.46 0391 aM11i Ins 122 1817 0.51 4.66 1.305 0213 200 0.59 _ 0.4211 0.51 1A8 0.401 0.028 200 1.20 1628 0,51 4.85 1.337 0.290 205 0,58 0432 D.51 1,40 call 0.021 205 1.18 163a 0,51 4.06 1.3]0 0206. 210 0,57 DA4 151 145 0421 0.013 210 1,is 164] 0,51 4A5 tA03 0.245 215 ON 0.437 Cal 145 OA31 0.00215 _ 1,14 1657 0,51 4A5 1.435 0.222 no 0.55 OA39 051 145 S40 .0 OD1 MO 1.12 1Oe6 0.51 4.4 14W 0.199 US 0.54 0M2 051 _ 145 0450 -0008 us 1.10 1.am 0.51 A'" 1.501 0.175 2l0 0.53 0.44 0.51 1.45 0.40 -0.016 230 1.08 1885 0.51 4.4 1533 0.151 235 0.52 0.446 0,51 146 0.470 -0on 235 1.08 1.603 0.51 A.4 IsS8 0.129 240 0.51 0449 051 145 OA80 4)A31 240 1.05 1.702 051 4.4 1538 0.104 245 0.50 0.451 0.51 145 0480 4.038 245 1.03 t711 0.54 4.a3 1131 0.080 250 0.50 0453 0.51 145 0409 4o4a 250 1.01 1719 0.51 4.83 1.W4 0055 255 049 0455 osl 1.45 0.509 .0.054 255 1,00 1.]2] 0.51 4.83 1,606 0.031 2SO 0.48 0457 osi 1.45 0.51E 4061 260 Dan 1735 0.51 4.03 1.729 0006 265 047 0.4W osi 145 D.528 4099 265 0,97 1,743 as, 4.83 1,762 4.010 270 0.47 0Aa2 0.51 145 0,538 -0.077 270 0.96 1151 0.51 4.82 1.]4 Anus 275 a." 0.44 0.51 145 D.548 -0.084 275 0,94 1759 0.51 402 1,822 AND 280 045 SAW O.St 145 0.558 4D02 280 Soo 1.IN 051 4.a2 +.859 4093 285 0A5 DAN os, 145 0.558 .0100 2a5 0.92 1T14 0.51 4.82 1.092 4118 220 a4 0.462 0.51 tIs 0.5E7 _0 ins 290 SO, 1.791 0.51 let 1025 4).1.3 295 04 0.471 0.51 145 Osa7 -0.118 295 O.ao 1TBa 0.51 4,82 1957 41119 300 on 0.473 0.51 144 D.5e7 -0.124 WO 0.88 1.795 0,51 4.82 1.900 -0.14 Mod. FM Minor gnome. Volume (cubic it) • ).a96 USE. FM Map, Stars. Vntorrm lcubl. Rl• 32.130 ernmra00 volume (acre-nl• 01e0b Men. FM Major atonal. Volume (acmAj, 0.73)) UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013 tlD-0emlepn v2.J4 Net Emrk,As Mooned FAA - 2ntrz015. 104 AM II I 1 r i J J L_J 1 I 1 I I DETENTION VOLUME BY THE MODIFIED FAA METHOD Project: Avago B3 Basin ID: NORTH EXISTING UD9almeen Q.M NoM Emsvmg.Aa. MOW6d FAA UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November2013 3111(1013, 10,01 AM DETENTION VOLUME BY THE MODIFIED FAA METHOD Project Avago 83 Basin D: NORTH PROPOSED (Far calchnMMs less than 160 acres only. For larger catchments, this, hydrograph raudng fled ad) (NOTEfor catchments larger than 90 acres. CUHP hydrograph and routing are recommended) Debur inatlon of MINOR Detention Volume Using Modified FAA Method I Determination of MAJOR Datention Volume Using Modified FAA Method I Calcnmem Draml. Impervl.u3neas Ca marl Oranem Area I'mm elmpmem MRCS S0.1 Cwoup Reuan PInId RO D.mrs.n Cme.1 Time Of Conanmoe of Wouro en A•owabb r1M Release one OnMourPrecgrar- DnIBnRumbelOFFermula I•G'PAICarTJ=C, Coeffci.m On. eoemci.m Twm C-111riam Three I. • 17.00 percent A • B.4]] some Tyye= c A, B, c, ArO T • 10 as ye(2, 5,10, 25. 50, or 1 DO) Tp= 5 de. olasua P,= t,b inched C, • 28.50 c1• 0 C,- o.7e6 Runoff c • infl. Pe W Runoff OuWn • AIoMle Paek OVID. Re. O"ut- Mod. FM Minor Somalia Volume - Mod. FAA Minor 9orage Volume- Redd Ra11e Inf- Aoueem Daian Impair, Volume In Foo., maaM1,: acMelh, sraM1n CMchnImm Dranal. lmperhmam ea Cashmere Drone,. Area Pned..elopm.m MRCS Soo Group Amum Pmdd for Dmmrmh Conaol Time of Concemraoon of weemhed M.weele Unit Release Res OnMourl'....Uuan DoM9nRi.NIIDFFormuW i-Ci P,IIC1eTJ-C. Co.nmanl one Coeflclem Two Covement Three I.- _ 17.00 Pncem A• 9473 Type. c A.B C, or T• tM yess12. 5.10.25. 50. or 1001 T. 5 mmNa a- 1.Da elate. P, • 2M tandem C,• 2850 c.- 0 C, • O74 0,33 Runoff Coemclem C= 0,55 14.72 cf. Inflow Peak Runoff au,n= 50.13 214 _ oh, MmMle Peak O.M. Re. OOCN= BA] 10.180 made Feet Mod. FM Maim Bomas Volume • 35 056 0.34 some Moo. FM Maim 5"s Volume- DA06 PROPOSEDFAA STORAGE: 0.805 AC -FT EXISTING FAA STORAGE: 0.738 AC -FT REQUIRED ADDITIONAL eft STO ofe cuticMe • 1.2 0804 AC -FT scrM homes homes Insider � Senate O'fis Ham crVolume N al I DmlMea I iurvicurlm0•elM soehud Anumany Volume Fmmm Ouow son,'..' I :2. 0 0.00 D.wO 0.00 dw 0.000 D.000 - D D.aa a.aoa O.Do - 9.000 01000 5 4,71 0,10, t.o0 2,84 0020 o.D62 5 9.a2 O.Ns {.D0 a.MS 0.280 10 3.75 (TIED 0.75 2.13 0,029 0.132 10 )Bl Teed � 0.75 9.098 0.452 15 3.15 034 Dar 1.80 0,039 OA4 IS 6A3 0.892 0.67 0.13 0.582 20 2.73 0.2M 0.63 178 0049 DIM 20 5.57 0.7BB 1 0,63 0 ] 0,638 25 2.41 OSM 0.00 171 0.059 0201, ZS 413 0,586 Too .log 065E 30 2.17 0.231 0.55 1,M 0.069 0.212 30 4.At D.955 0,58 one /IOM 0.n7 35 1.9E 03M 0.57 112 0,078 0.220 35 4.CA 1,016 0.57OM1 0.755 40 1.82 0.314 0.5E 1.80 0.089 0126 40 172 t.MB 0.5E0.24 0.775 45 1.4 0.]P ON 158 0.098 0.230 45 3,45 1115 U.M0.326 0.789 50 15a ONO O.Ss 158 0.10E 0.212 50 J.33 t.1M 0.55O.35B _ 0.7455 IA6 0.351 0.55 1.55 0117 0233 55 3.03 114 0.550.391 0.803 90 1.40 0.361 0.54 154 0127 0.234 6O 2.85 1.22E 0,540.424 0.905 a5 1.32 0,370 0.54 1.53 0.137 0.2a3 6s 2.70 1.22 O.N 5.10 _ 0.457 0.54 70 1.2E 0,379 0.4 1,52 0,147 0.232 70 2.57 t.2e0 0.14 5.07 0.480 0.001 75 1.20 0.307 0.53 152 0.157 0,230 75 2.46 1.318 0 5.05 0.522 079E so 1.15 0395 0.53 1,51 0.166 0.228 BD 2.34 1.344 13 5.03 0.565 0.139 85 1.10 0,402 _ 0.53 1.50 0.17E 0,226 85 2.24 1.]60 0.53 502 0.5117 0,731 90 1.05 040E 0.53 150 0.186 0.223 80 2.15 1.]Bt 0.53 Soo gno 0,771 _95 1.0, 0415 0.53 1.50 DAVIS 0.212 95 207 IA13 0.53 4.9E TM 0.761 100 0,98 0.421 _ 0.53 149 0.208 0216 100 2.Oa IA 0,53 4,97 Ban 0.74E 105 0.4 OAP _ 0.52 ' 4 VOLUME CALCULATED USING 1.03/1491 0.52 4.M 0.71E - 01M 110 its 0.91 aas 0.432 - CAM 0.52 0.52 4 - 1.A THE FAA METHOD IS 1 e7 1..1 osz 052 41s 4.94 0.750 0.7883 a.7v 0.70E120 o.M 0443 _ 0.52 1ASUBSTANIALLY LESS THAN 1.75 D.e2 COD uAls de,9125 0.63 0.8052 1.4 110 0,52 4.93 DA4e D.en 130 0,81 0453 052 1 THE VOUME CALCULATED IA. 0.52 4,92 0.881 Due 135 0.79 O457 a52 14 USING THE V=KA METHOD. 1 1,556 0.52 4,91 9,913 0.43 140 0.77 0452 052 1A THEREFORE, THE LARGER 1.so 1.572 0.52 4,01 0946 0.628 145 d75 Dam 0.52 to 1,52 1.588 0.52 4,90 0.979 0.607 150 0.73 0470 0.52 1,4 STORAGE VOLUMES 1.4E 1.600 0.52 4.09 1.011 - 0139 155 0.71 0474 052 14 CALCULATED IN THE V=KA 145 1 W4 0.52 AAA 10.4 0.570 160 D.89 0,4711 0.52 14 METHOD WILL t 1.827 052 4.58 1.076 0.551 165 Deal - D.. 0.52 a BE USED. D2 lap 1.0 052 4.ad 1.109 - 0.51, 170 am 0.48s _. D.51 1,46 0.343 0143 170 1.35 1.653 os, 480 1.142 - 0.511 175 0.05 0.489 0.51 __. u0 0s52 0.137 175 133 tMs - 0.5I 487 tna 04e0 14 a.4 0A02 get 146 O.= 0130 lad 1.30 11n 0.51 4,87 1.207 0470 tM Cu 04% 0.5, 1A6 0.3n 0.124 as 1.27 1.M8 0.51 4.4 1.240 0440 In 0.51 04" 0.51 1,40 9.382 011E Too 1.25 1.700 0.51 4.8E 13m 0127 to ON 0.502 0.51 I46 9.391 0. 111 195 1.22 1.711 0-5, see 1.30r O OS 300 O.SB 054 0.91 148 0A01 0.1N 200 t.20 1.722 0.51 ass t.33] 0.384 205 o.5a 0.50E 0.51 140 UAtt 0006 a 1.16 1.732 0.51 4.85 1I t.3T0 D.362 210 0,57 a512 0,51 145 0A21 0.091 210 1.is 1742 1 0,51 4.85 1,13 0,340 215 0.56 0,515 _ 0.51 145 0431 a0" 215 1A4 1.753 1 0.51 Aga 1A35 �, 0.317 _no 0.55 0.518 0.51 1A5 0440 0.077 no 1.12 1763 0.51 4.94 1"a 0.295 US O.N 0.521 u.51 145 0.40 0.070 Us 1.10 1.772 0.51 4,114 _ 1.501 O.P2 230 0.53 0.Sn 0.51 1.45 DAM 01163 230 1.08 1732 D.51 Coil 1.533 0249 235 0.52 0.52E 0.51 1.45 0170 0.05E 235 IN 1791 0,51 4.4 1.58e 0.225 240 0.51 0.52E d51 145 0480 0No 240 1.05 1800 _ Dal 4.4 1.598 0102 245 0.50 g.531 0.51 145 0.489 0042 245 1.03 1.809 0.51 4.53 1.531 D, 178 _no 0.50 0.534 _ 0.51 1,45 OABB 0.035 250 1,01 1s18 05l 4s3 lA4 0155 n5 __.. 0.49 0,537 0,51 145 0.50E 0.028 _. 255 1.00 1.527 0,51 483 ISM 0.131 380 0./8 0.53E 051 1A5 0.51E 0020 280 0.80 1.035 0.51 4.83 1.729 0.107 20 DA7 0.542 as, 1.45 0.520 0.013 Me a.87 1.44 031 413 1.762 0,082 270 0.47 os" 0.51 1.45 0.510 0.000 270 0.96 11852 0.51 4.82 1.794 0.058 275 0.48 0.546 0.51 1.45 0.548 4002 275 0.4 1.860 0.51 4.82 1,027 0.04 280 0A6 0.549 0.51 1A5 0.559 -0009 200 0.23 1 1,806 0,51 4.62 1.850 O.00a 235 OAS 0.551 0.51 1.45 O.Me 4.017 285 0.92 1,87E O51 4.52 1.892 41I6 290 OM 0.553 D.51 1.0 01n -D024 2M 011 1,84 0.51 412 1.925 -0.41 295 ON 0.5% 0,51 145 0.587 4.032 38s 0.89 I.892 0.51 4.a2 Isw -0.46 3110 Ob a558 051 to 0587 4039 300 O.Ba 1.BB9 951 482 1.no -DAL Mod. FAA Minor SoraOe VOW" (Deals R)s lo,14 Mod. FM Major storage Volume(euMC M1)• a6,068 Mod. FAA Miner Storage Values McmAi- Oa137 Mod. FM Meter Som4 Volume I ... aU- DAM UDFCO DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released Noyemaar2013 UDF[iatehaon-P2.0 NOM Proposes al., MmlAed FAA 2011QOI 5. 10,04 AM DETENTION VOLUME BY THE MODIFIED FAA METHOD Project Avago B3 Basins): NORTH PROPOSED 2.5 2 1.5 U U N E > 1 0.5 0 0 50 100 150 200 Duration (Minutes) �Ynw imm d>wu VUYmn—YNw>mrn Ouebw Wluma YNw>brm 6rwpn Vtlumn �Ynpr>mrm Nfn+r Velumn�Ynpr Inflow and Outflow Volumes vs. Rainfall Duration i 250 300 350 UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34. Released Noventer2013 Ynpe bmrm 1orsBv vdumn u ,dm Q.3f Wn P.bymeeri wmmfe FAA 2111ao+5.1001 250 300 350 UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34. Released Noventer2013 Ynpe bmrm 1orsBv vdumn u ,dm Q.3f Wn P.bymeeri wmmfe FAA 2111ao+5.1001 DETENTION VOLUME BY THE MODIFIED FAA METHOD Basin D: SOUTH EXISTING (For catchments Is" then 160 acres only. For larger catchments, use hydrograph routing method) (NOTE: for catchments larger than 90 acres, CUHP hydrogro ph and routing are recommentled) ❑etermnaeion of . 11z Oatantion Volume Using Modified FAA Method I Datenmination at MAJOR Detention Volume Using Modified FAA Method Camnmem Drainage Impemouanea9 Cacnmem Drm,age Area Pre4wekpmem WCS 5.9 Gaup Repm Paned let D...- Cartel Tme of Cnm eneeevn of W asem.d Atreable Unt Related See OneJrour Pr Vcsen Oe.Ign R.m%d IOF For.I& I • C,- PAC1TJ=C. cpener.m One C-ftwnm T. Caeauem Tmee I.=fflj�A. pemem A a Type=R C, or0 T=,ee. Q, 5, 10' 25,so, or 100) Tc=rtm,ea C.Iepe P, =mchea C, C, = n C1. 0.739 Cathmem Drainage Impart. Cachmem Drainage Area Predrvelopmem NRCS SOY Group Regan Paned for Dmmc.n C.mrd Time al Concemrmon of Waemhed AOow.ble Unrt R.I... Rate One3mur Prevpnmon Design R4lnMelUf Formula I•cj' P,IICpTJ•C. Ceemclem one CaeMcam Two Caenruem TMee 1.. 3214 a.. A • 15.013 . Typo= C A. B. O0r0 T= ta0 1.. (2. 5,10, 25. 50. m100) T.- 5 m111M. P,= 2.Bfi Inches C. - 28.50 C,• 1n Le• 0JI19 Ruwn CoaMcwm C= 0,39 Runoff Coeercienl C= 0.52 Ing. Park Rleen Op.n= 2769 cis InOow Perk Runoff Cpm= 53A1 cfe AlawabN Peek OuNow Rae Oprour= 462 cfe ABomole Perk 001uw Rate ap<w= 15.01 cfe M od. FAA Minor Storage Volume= 20,860 culk Mel Mod. FAA Malay SW,.,. Volume- _ 58.905 sulk Mar Moe. FAA Miner Smrega Vekme• 0.4" imm,ft Mod. FAA Maim Storage Volume a 4.352 scm,ft - Enl n•3p •tor en Du • I•¢ rnl l•r a Vnlur 4er .r 4MrnNes named Rated me. Agate". Awrager' Ou81ow SmmgO Rre.a Rand.B Imlaw AD bnmd w qw raga oenaw SI.m e Dursem Intense, VMmne Fewer OAR. Vakma Volume Durvion Imensdy Volume F.ter Oust- Vowme Vawme mname aWealM sre4eN W cM am-fam aeeMaal nikMea rlaha.lM .ran., m cfe -4eel eve -feet N m N aW m 0 O.OD o.600 000 0.00 9.000 0.000 0 0.00 9.000 0,00 0.00 01000 oA00 5 Art 0.191 1.00 4.52 0.901 0.180 s 9,62 0ma 1.00 15.07 0104 0466 1a 3.15 0304 0.15 639 0.an 0.251 10 2e1 1 0.e07 0.15 _. n30 of so 0s52 15 3.15 0.302 061 3.01 0.062 0.320 15 0.43 1,141 a.61 10.05 1,206 0.SJ4 20 273 0441 0.60 Z83 0.078 0.364 20 5.57 1315 063 2.42 0.200 1.050 25 2A1 0.09 Sao 221 0.093 0.305 25 433 1459 0A0 9.04 0.311 1.147 30 2.17 0528 050 2.64 0.109 Oars 30 444 1.518 0.58 6.79 0.303 1.212 35 1.98 056, 0.57 2.50 0.125 B.am 35 4.04 1915 0.51 8.61 0.415 1.MO .0 132 0.590 0.56 254 UA40 0450 40 - 3,72 1702 O58 &4e - 04m t295 45 IAS _ 0616 0.58 2.51 SAN 0A60 45 3.45 11138 0.56 8.37 0.519 1.319 50 153 0639 0,55 219 OA71 0487 50 3,22 1.907 0,55 us 0.511 1.336 55 1.49 0.660 a.55 347 0,187 0.473 55 3.03 1809 _ 0.55 8.22 _ 0.623 1.348 SO 1.40_ 0.679 054 245 0202 0420 Bo 2.85 2,026 0,54 8,16 0,675 1.352 65 132 0.696 0.54 243 0.210 0.428 85 2.7a 2.078 0.54 612 0.727 1352 TO 126 0 713 0'54 2.42 0.234 0.429 19 2.51 Z.128 0.51 001 0.119 1346 15 120 0729 033 2.41 0.248 0419 15 245 2173 0.53 0." 0.830 1343 e0 1.15 0242 0.53 240 1265 San 90 2.34 2216 0.53 8.01 0a02 13]3 S5 1.10 0.7% 0.53 2.39 0,250 O.a25 95 2.24 2256 0,53 7.98 0.934 1.32_2 su 1.a5 0109 0.53 2.39 0.206 0an SO 2.15 2,294 0.53 2.96 0.086 IAMB 96 1.01 0780 a." 2.30 0.311 a409 95 2.07 2.330 v.53 7.93 1.030 1192 in 0.93 0792 0.53 2.37 0,321 0465 too 2,00 2.364. 0,53 2a1 1,090 1,274 fY5 0.94 6903 0.52 237 0.343 a.400 105 1,93 2.307 0,52 1,90 1142 1255 110 Dal 0.813 0.52 236 0.358 0455 110 1,57 2.428 0.52 7.06 1.194 1.23A 115 0.86 ae23 _0.52 2.38 0.324 0.450 115 1.01 1 2.458 052 Tag 1.246 1.212 IN a.96 0833 0.52 2.36 0.359 OA44 120 115 2487 052 1.115 1.299 1139 125 0.83 0842 0.52 2.35 0406 0.437 125 1.20 2.544 0,52 2.84 1350 1155 130 081 _ 0.65, 052 2.35 0420 0431 130 t65 2,541 052 1401 114_0 1>5 0.T9 O.BSO _ 0.52 2,34 0.436 0424 135 1,111 2.561 0.52 _2.83 7.82 1453 _ 1A 13 140 On 0068 0.52 2,3a 0A52 0416 _ 14a 1,M 2.591 a52 _ 7.81 1505 1.M 149 0.75 0.816 0.52 2.3" 0461 0409 145 1.52 _. _ 2.815 0.53 7.80 1.55) 1.050 150 0.73 Dam 0.52 2.34 0483 0401 150 149 2.639 0.52 7 29 1Sao 1030 155 011 0.891 052 2.33 0490 0393 155 145 2.861 052 718 1601 1000 180 OAR 0899 0.52 2.33 0.514 0,365 ISO tA2 2.683 0,52 7n 1713 0.970 ,a5 ae, a.B06 Osa a.a] 0.5.0 ov. IRS la. 2.704 n.53 176 1785 a,B40 170 ON _ 0913 asi 213 0.545 0.388 17a 1.35 2725 3.51 7.76 1817 0.908 195 set 0.1. 0.51 2.33 0.561 0.359 195 1,33 2,945 0.51 7JS 1 we can ,an 0.64 3.6M 0,51 2.32 0516 0.350 1S0 1.30 2.185 3.51 7.75 1.020 0.844 195 On 0032 0.51 _ 2,32 9592 0.241 IRS IV 2.11P4 051 774 1012 _ 0.812 190 Oal 0.030 0,51 2.32 0.607 0.33, ISO 1.25 2003 3.51 ]2] 2024. Ong 195 a80 0.945 a.51 2.32 0.623 0322 195 1.22 Z321 0,51 173 2010 0345 200 O59 0.95, 0.51 232 0.638 0,312 200 IM 2B39 0,51 2.72 2126 0211 205 0.55 0.952 0.51 232 0A54 0303 205 1.18 2,856 051 7.72 2.180 1676 210 0.57 0.962 0,51 231 0.070 0293 210 1,16 1 2873 0.51 7.72 2.232 3642 215 0.58 0.058 0.51 2.31 0.685 0283 215 1,14 2.890 Osi 7.71 2351 0.6as 220 on 0.923 0.51 231 0]01 0.273 220 1.12 2A08 0.51 2.91 2336 0,571 225 p.54 _ 0619 0,51 2.31 0216 0,263 225 110 2,923 Ost 7,70 2,365 0,535 230 on 0.98, 0.51 231 0.732 0.252 230 1As 2038 0.51 710 2440 BASS 235 052 1889 O51 2.31 D.212 0242 235 1.08 Z954 0.51 7.70 2.491 0462 240 0.51 099a 0.51 211 0.183 0.231 240 1.05 2509 0.51 189 2.543 0426 245 0.50 0.999 0.51 2.31 0.779 0.221 245 IA3 2,984 a-51 7.69 2s9s D.398 250 0.50 1O04 0.51 231 0194 0.210 250 101 2,999 0.51 7.69 2641 0351 255 049 1000 0.51 231 0,810 0 1 a 255 1,00 3013 051 180 2.699 0314 260 0.46 1014 0.51 2.30 0.925 0.181 250 0.88 3.027 0.51 7.68 2A51 0226 265 041 I D18 0.51 2.30 0.841 0.128 265 0.97 3.041 0.51 750 2,803 0236 270 0,47 1.023 0.51 2.30 Sam 0.162 210 0.96 1054 a.51 760 2,855 0.200 225 046 1.027 0.51 220 _ 0.812 a 156 275 0.94 3.066 0.51 7.67 2,907 0.161 260 046 1.032 0.51 230 0.838 a.I. 280 0.93 3081 list 7,67 2.952 0.122 255 045 tab 0.51 230 SAW 0.133 205 0.92 Sam 0,51 261 3A1O 0.093 29D a 44 1.041 0.51 2.30 0.919 0.122 290 0,01 3102 0.51 267 3052 0A44 285 04. I.pas 051 2.30 0.834 011a 295 0.69 3119 051 766 3. 111 0.005 ]00 S.3 1048 0.51 2.30 0.950 0.089 MO 0.00 3.132 0.51 7,66 3.166 41.au Y cd. FAR Minor SmfN. Volume (eusk SO) 20,000 Mod. FAA M alor Storage Volume lcusk it, 6e606 mr.9e volume mcn•R)• 041e1 M W. FAA M Mor Storage Volume(.roAl• 13523 UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released No temher2013 l CftrOpn_v234 Sma1 EAanatle Modhi d FAA 2111 QOI5, 10 05 AM ' DETENTION VOLUME BY THE MODIFIED FAA METHOD 1 Project Avago B3 Basin D: SOUTH EXISTING 91 I I I F— L I I I I 'J0. De1m0oli�v2. 34 Sou E.wnp .Ww.idFM UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released NowmEer2013 2111a015. 10 0S AM 1 I 1 I I u I I I I 1 DETENTION VOLUME BY THE MODIFIED FAA METHOD Project: Avago B3 Basin D: SOUTH PROPOSED (For Catchmenta lea, than 160 aeon only. For larger catchr4annb, plus hydrograph routing method) .,r catchments larger than 90 acres. Cl 1 .-graph and r i I Datemanal hon or MINOR Detention Volurn, Using Modified FAA Method I Determination of Detention Volume Using Modified FAA Method I CaCunen Doonaga lingering.. Clacmnam D.I. Mee Predonlupmem RRCS Soil Graul, Ragan Perot for Oearson Consul Time d Concenbanon of WaMMed A11=1e U. Rekane Rae On 4I... PnupNEOn D..IlunfYMWIDFFa.W 1•C,' PACo TXC. C..niciorl CONfcum TwO Cavttkmn TNee 1.= 42.89 Percent A - 15.m3 Type= a A.8 C, orD T= to yaws(F.5.10, 25. 50. or 100) Tc= 5 mnutan a= oaD cbl.cre Pi• 140 Ilan.. C1= z250 C,= 0 C. = 0.789 Rinaff co Muo,l C - 0,43 ling. Pew Ronan a"- 3053 c1s AOawbM Pew Outal Rare 1a = 452 d. Mad. FM Minor Swinge Volume+ N113__wMg Mt Mod.FMMln-Shinp.Volltme• OLMA screft 5 .Emv, u."n +4 Increase V 1- i+erea „n Randan Rapid-M•ru1e: Rapid Inflow Ac=nt Aw+Oe Mw Oia Durango, lownwe, I VoWme FaAn OWow VOWme mn.Ys npaclls oM.et m ch vNget CaMM1mnd Dr.nM. Inborn.... C6nmant Drnnuai Aga Pradewlapmam NRCS Sal Group Ragan Palau wan Dela ton C..ul Time of corporeal al WeanM1ed Movable Unit Floome Rate OnaJlour Pracoppon Oalapn R.InOpIDF Formula I•C,'PV(C1TJ"C, Ooodulan On. OoeeMlad Two Coenalant Three I.= 42.99 Pe,cam A= 15.073 Type• C A, B, C. nO T = 100 yeas (2. 5. 10. 25. 50. or 100) Tc= 5 mimeos P,= 2ae Ircnes C1 a 2850 C,= 10 C, • O.7B Runde C..nciem C = 0.58 Iof. Paw Runon Opan= as 57 AYnwMe Pew Outflow Raw Dpwe= 15.07 Mad, FM Mlaw Storage Velum.= 62,082 Mod. FM M last SwaM. Volume- 1.426 PROPOSEDFAA STORAGE: 1.425 AC -FT EXISTING FAA STORAGE: 1.352 AC -FT R. EOUIRED ADDITIONAL J 1.20 = .0876 AC -FT --:A ,s6mraps RaMan Rnnlan Inflow AeFagnem A.M. OunOw VoWme 0". Imemdy Volume F.dvr Ourflow VoFmm ot oSE ncnes/la ecg,4.at m oh scn,hot D 0.0 O.00D D.Dg 0.00 0.000 DMO 5 C71 0110 1.00 4.52 0.031 0.119 t0 3.75 DIM 0.75 3.39 D.047 0.258 15 3.15 OAM 3.01 DODO a.350 20 273 OAa] _0.67 _ _0.0 _ 2.013 0.070 0.400 25 2.41 0.530 Deo 2,71 0.093 0A45 30 2.17 0552 0.58 IN 0,109 OA73 35 In 0.819 0.57 _ 2.58 0.125 04" 40 1.82 0851 Gas 2.54 0.140 0.510 45 IM 0.679 OAS ]51 0.156 0.523 50 1.58 0.704 0.55 249 0.171 0.533 55 148 07V 0.55 147 0.187 0,540 90 1Aa d748 OA4 245 0202 0.546 55 1.32 0.70 0.54 2A3 D21a 0.550 70 1.26 07M 0.54 2.42 0.234 0.552 75 1,20 DADS 0,53 241 0.249 0.553 g0 1.is 0.818 a.53 2.40 0.265 0.554 95 1,10 Dan D.53 2.39 0.280 0.553 90 105 0.941 0.53 2]6 0.206 0.551 85 La, 0.88a 053 2.38 0.311 0542 100 0IS 0.613 0.53 2.37 0.327 a,5" 105 0.91 0.895 0.52 _ 2.37 0.343 0.543 I LD 0.21 0.307 0.52 236 93sa 0.539 115 0.58 a 908 0.52 IN _ 0.374 _ 0.53A 120 ON 0,918 0.52 236 0.369 0.529 +25 on 0.928 0.52 235 DADS 0.524 t30 0.01 0938 0.52 2.35 0420 0is : 135 0.72 0.949 0.52 IN o.AH 0,512 140 an 0,957 2.N 0.452 0.505 f45 0.75 _ Oasfi _0.52 0,52 2N 0467 04" 1SO 0.73 0.974 152 IN 04a3 0492 155 0.71 0,083 2.33 0.498 04" tSo 0.60 a.991 - _0.52 0.52 233 0.514 04P ,es 0,as aaae z.s3 D.S. 046. 170 06e tam _0,52 0.51 233 0.545 0481 173 0A5 1814 M51 2.33 _ 0.561 0A53 ISO 0.64 1021 0.51 2.32 IS)5 0445 145 0.62 1.028 0.51 2.32 0,502 04M 0 0.51 1.035 1151 232 0.607 0420 1DO ON 1042 0.51 232 0.623 0419 200 0.39 10" 0.51 232 D,638 0.410 205 see 1 D55 0.51 232 D654 0 401 210 0.57 1as, 0,51 131 0670 0392 215 a." 1067 0,51 231 0.685 0.382 220 0s5 1a7] 0.51 2.]t 0]01 0.373 225 O.N 1.079 0.51 231 0,718 T353 230 0.53 1.005 0.51 231 0732 0.353 235 0.52 1.091 0.51 2.31 0,747 0.343 240 0,51 1 096 _ 151 211 0.763 0.333 245 0.50 1.102 0.51 2.31 0.779 0.323 250 0.50 1.107 0.51 2.31 0,794 0,313 255 0.40 1113 0.51 2.31 0.810 0.303 no 0.40 1.113 0.51 230 0.525 0.292 NO 047 1.123 0.51 IN 0041 0,252 270 0,47 lAn 0.51 230 a9as 0.271 275 OAS 1133 0.51 2.30 0872 0.261 zoo 045 1.in 0.51 2.30 Dole 0.250 285 045 1,143 0.51 2.30 0.903 0.239 no a." 1147 0.51 2.30 0.919 D12S 295 0" 1.152 0.51 2.30 OsN 0.21a UD-0Opooa n v2N Soup PropowdM Modified FAA 5 982 0582 "DO 15.07 10 7e7 0939 075 11.30 15 643 1.in 0.67 _ 10.05 20 5.57 1.364 083 _ 9.42 25 4.93 1.510 0.00 9.04 30 4.44 1631 O.SS e70 35 4.04 1734 0,57 IS, 40 3.72 1_823 0,56 8.48 45 3.45 1A03 O.So 8.37 50 3.22 1.974 _ 0.55 8.29 55 3.03 2.038 0.55 5.22 60 2.65 2 M 0.54 6.16 a5 2.70 2.152 0.54 8.12 70 2.57 2202 0.54 8.07 75 2.45 2249 0,53 &04 THE FAA METHOD IS SUBSTANIALLY LESS THAN THE VOUME CALCULATED USING THE Val METH THEREFORE, THE LARG STORAGE VOLUMES CALCULATED IN THE Vdz METHOD WILL BE USED 150 1.40 2.731 155 1,45 2.755 lea 1,42 am ,as I.a. a".. 170 1,35 2MI 175 1.33 2.612 ,so 1.30 2.862 185 1.27 28a2 ,so 1.25 2.901 195 112 2.020 200 110 2.838 205 1.1a IRS? 210 1.is 2.974 215 1.14 2.992 In1.12 1000 225 1.10 3.025 230 1,00 3.041 235 1.06 3.057 240 1.05 3.073 245 1.03 3.08E 250 1.01 3.104 255 1.00 3.116 no 0.98 3.133 NO 0.97 3.147 2)0 ON 3.161 275 a.W 3_175 260 0.93 Mai; 285 0.92 3.202 no 0.91 3.216 no DID 3.219 7.56 OD. ?w ER 7.85 7.84 7.63 KA 7.92 7.81 7.60 0.52 7.79 6sz -25a am 7..n Wig_¢ T7e 0.31 ]15 0.51 775 151 774 0.51 7.73 051 713 0.51 7,72 0,51 7,72 0,51 7,72 0.51 ].)1 0,51 7.71 0.51 7.70 0.5, 770 0.51 7.70 0.51 7.69 0,51 7.69 051 7.69 0.51 7.68 0.51 7.08 a 51 7.68 0.51 Tea 0.51 7,67 0.51 TB] a 51 7.67 0.51 T6) 051 766 0.+04 0.155 0.20E DAN 0.)84 0.074 1.105 "ISO ,.25a 1,310 1,3" 1.3" 1,4a3 1.416 1.423 1.425 1424 1,410 1.411 1401 1 388 1,374 1.357 338 320 1.290 1.21a 1.253 1.220 1.203 1,177 1,150 1122 1 094 1.094 1 dIs 1.004 9.073 0.941 0,909 0.877 0844 0.810 0 777 0,742 a.Tae D.973 0 837 0.602 8.566 Oo30 o A93 1456 0419 1382 0.34A Dam 0,269 0,230 a 192 0153 a.115 Mod. FM MIno, Storage VIA...(epaM R.)- 24,113 Mod. FM M alor Storage Volume (cubic 8.1- Ill Mae. FM Manor Storage Volume taeas4a)• 11A636 Mod. F M M afor Storage Volu me(aeraAj 1 1.4252 UDFCO DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013 V11R015, 1005 AM I ' I DETENTION VOLUME BY THE MODIFIED FAA METHOD ' Project: Avago BS Basin D: SOUTH PROPOSED UOFOD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Rekased Nover 2013 J6 e%i*on_Q USa Pwp d. c. MoEeiee FM 21"Q015101, ". PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT*: POND NAME: NORTH POND DATE: 03/09/15 1 319)2015 9.44 AM Required Detention Volume: V,=KA (1.781— 0.0021' — 3.56) K"'° = 900 _ (0.951-1.90) K10 1000 K — (0.771 — 2.65) 1000 eew•�r .o ...oRTIN �.. For Type A Soils : L i„I,a = (— 0.00005501 - 1' + 0.030148. 1— 0.12�-1 12 *Equations SO-1 through SO-5, UDFCD (V 2), Chapter 10, Pg SO-9 Where: V, = Required Volume Where Subscript i = 100-, 10- or 5-Year Storm (acre-ft) K; = Empirical Volume Coefficient I = Fully Developed Tributary Catchment Imperviousness (%) A = Tributary Catchment Area (acres) I = 100.0 (°/a) A = 1.09 (acres) Kroo = 0.172 Krp = 0.093 K5 = 0.074 V100 = 0.187 (ac-ft) 8,148 (cu-ft) V,o = 0.101 (ac-ft) 4,420 (cu-ft) WQCV= 0.055 (ac-ft) 2,374 (cu-ft) V100,REQ = 0.242 (ac-ft) 10,622 (cu-ft) V+o,REo = 0.156 (ac-ft) 6,794 (cu-ft) NRCS Hydrologic Soil Group: C & D Max 5-Year Release Rate = 0.2 (cfs) Max 10-Year Release Rate = 0.3 (cfs) Max 100-Year Release Rate = 1.1 (cfs) Maximum Unit FInw Rplpanp Ratp% If-rC arrpl from An-iirp nptpntinn Farilitipe Design Return Period (Years) NRCS Hydrologic Soil Group A B C 3 D 5 0.07 0.13 0.17 10 0.13 0.23 0.30 100 0.50 0.85 1.00 -j aore au-i, uuri-u Iv et. unaprer 7u, rage au -a Detention Volume North WSCHLAGETER114.0833-Avago- Building 3\ENG\DRAINAGE\2015.03.07_MINOR AMENDMENT SUBMITTAL 3\Det.Vol KA.xis PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECTM POND NAME: SOUTH POND DATE: 03/09/15 ' 3/9/2015 9,44 AM Required Detention Volume: V, = K,.1 (1.78/-0.00212 —3.56) K10° 900 K I = (0.951-1.90) 1000 K—(0.77/-2,65) 1000 MARTIN ....TIN . oR... For Type A Soils : 0.00005501 /' + 0.030148 1— 0.12) 12 *Equations SO-1 through SO-5, UOFCO (V 2), Chapter 10, Pg SO-9 Where: V; = Required Volume Where Subscript i = 100-, 10- or 5-Year Storm (acre-ft) K, = Empirical Volume Coefficient I = Fully Developed Tributary Catchment Imperviousness (%) A = Tributary Catchment Area (acres) I = 100.0 (%) A=1 1.56 (acres) K100 = 0.172 Km = 0.093 K5 = 0.074 V10D = 0.268 (ac-ft) 11,661 (cu-ft) V1° = 0.145 (ac-ft) 6,326 (cu-ft) WQCV= 0.078 (ac-ft) 3,398 (cu-ft) V100,REQ = 0.346 (ac-ft) 15,069 (cu-ft) V,°,REa= 0.223 (ac-ft) 9,724 (cu-ft) NRCS Hydrologic Soil Group: C 8 D Max 5-Year Release Rate = 0.3 (cfs) Max 10-Year Release Rate = 0.5 (cfs) Max 100-Year Release Rate = 1.6 (cfs) Maximum Unit Flow Release Rates lefs/aerel frnm nn-Sitp nptpntinn Faeilitipe Design Return Period (Years) NRCS Hydrologic Soil Group A B C 6 D 5 0.07 0,13 0.17 10 0.13 0.23 0.30 100 0.50 0.85 1.00 i aoie au- i. uur�u I v 4. unaprer iu, rage au-o Detention Volume South G:ZCHLAGETER\14.0833-Avago - Building 3\ENG\DRAINAGE\2015.03.07 MINOR AMENDMENT SUBMITTAL 3\Det.Vol KA.1ds ' PROJECT INFORMATION PROJECT NAME: AVAGO B3 ' PROJECT#: MARTIN/ MARTIN POND NAME: NORTH POND oo»e��ri»o �»a»awe DATE: 02/18/15 ' Required Water Quality Volume: ' Detention Sizing Method: WQCV NRCS Hydrologic Soil Group: C & D WQCV = a x (0.91i'—1.19i- + 0.78i)i 'Figure EDB-2, UDFCD (V.3), Chapter4, Page S-73 EURVa = I . I (2.0491 i — 0.1 1 13) rWQCV EURV=1.1.(1.2846-i-0.0461) ' 1LEED WQCV = (O.S�xI 0.43 ] EURV,.,t, = 1.1-(1.1381 i-0.0339) 'UDFCD (V 3), Chapter 2, Page SQ-24 'Equations SO-11 - SO-13, UDFCD (V 2), Chapter 10, Page SO-12 Where: t WQCV = Water Quality Capture Volume (Watershed Inches) a = Constant Dependent on Drain Time (Typically a=1.0 40-Hr Drain Time) i = Percent Imperviousness i WQCV = 0.500 (watershed inches) Required Storage = WQCV x (AREA)x 1.2 ' 12 'UDFCD (V 3), Chapter 4, Page S-69 Where: Required Storage = EURV x (AREA) [ 12 'UDFCD (V 3), Chapter 2, Page SO-24 ' WQCV = Water Quality Capture Volume (Watershed Inches) Area = Contributing Watershed Area (Acres) Area = 1.09 (acres) Required Storage = 0.0545 (ac-ft) F ' WQCV NORTH 2/19/2015 9:24 PM G:\SCHLAGETER\14.0833-Avago - Building 3\ENG\DRAINAGE\2015.02.11_MINOR AMENDMENT SUBMITTAL 2\WQCV.xIs I ' PROJECT INFORMATION PROJECT NAME: AVAGC B3 ' PROJECT*: POND NAME: T , -, ,- -,I-' SOUTH - POND 8 DATE: 01/00/00 ' Required Water Quality Volume: Detention Sizing Method: WQCV ' NRCS Hydrologic Soil Group: C & D WQC6'=ax(0.9li'-1.19i2+0.78i)l EL'R6" =1.1 12.0491 i—O.11l3) 'Figure EDB-2, UDFCD (V.3), Chapter4, Page S-73 LEED WQCV=(0.5)x[.[-QC[- EUR6"a=1.1 (1.2846 i-0.0461) r 0.43 F.G'RY; ,, = I.I (1.1381 i-0.0339) 1 'UDFCD (V.3), Chapter 2. Page SQ-24 •Equations SO-11 - SO-13, UDFCD ry.2), Chapter 10. Page SO-12 Where: WQCV = Water Quality Capture Volume (Watershed Inches) a = Constant Dependent on Drain Time (Typically a=1.0 40-Hr Drain Time) i = Percent Imperviousness i = 1 oo.oeie WQCV = 0.500 (watershed inches) (l rEI Ri" Required Storage =L[t'OC6"lx(.4RE.4)x1.2 Required Storage =L 1x(AREA) 12 12 'UDFCD (V 3), Chapter 4, Page S-69 •UDFCD (V 3), Chapter 2, Page SQ-24 Where: WQCV = Water Quality Capture Volume (Watershed Inches) Area = Contributing Watershed Area (Acres) Area = 1.56 (acres) Required Storage = 0.0780 (ac-ft) 2/19/2015 9:25 PM WQCV SOUTH G:\SCHLAGETER\14.0833-Avago - Building 3\ENG\DRAINAGE\2015.02.11 MINOR AMENDMENT SUBMITTAL 2\WQCV.xls PROJECT INFORMATION PROJECT NAME: AVAGO 83 PROJECT #: POND NAME: NORTH POND DATE: 03110115 Required Water Quality Volume= 2374 (ft3) 0.055 (aft) Water Quality Surface Elevation = 4916.06 II Required 100-Year+ WQCV Volume= 10522 (ft3) 0.242 (ac-ft) 100-Year+ WQCV Water Surface Elevation = 4916.84 Total Pond Volume = 123699 (ft3) 2.840 (ac-R) �� i Incremental Volume= /3 (ELE.I' 2 — ELE- 1) x (.1RE 1 I + ARE, 1 2 + ( AREA 1 x AREA 2) 7= ) Contour Elevation Contour Area f. Volume ft, Cumulative Volume (fN) Cumulative Volume acre-ft 491520 0.0 0 0 0.00 4916.00 6714.1 1790 1790 0.04 4917.00 14552.3 10384 12174 0.28 4918.00 17254.8 15884 28058 0.64 4919.00 19479.4 18356 46414 1.07 4920.00 21800.1 20629 67043 1.54 4921.00 24233.2 23006 90049 2.07 4921.30 25010.2 7386 97435 2.24 4922.30 27536.4 26263 123699 2.84 NORTH POND 3/10/2015 8:07 AM G:\SCHLAGETER\14.0833-Avago - Building 31ENG\DRAINAGE\2015.03.07—MINOR AMENDMENT SUBMITTAL 3\Pond_WSEL.dsm PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT #: MARTIN / MARTIN POND NAME: SOUTH POND DATE: 03/10/15 Required Water Quality Volume = 3398 (tt3) 0.078 (ac-ft) Water Quality Surface Elevation = 4910.38 I Required 10-Year+ WQCV Volume= 0 (ft3) 0.000 (ac-ft) 10-Year+ WOCV Water Surface Elevation = 4909.50 ' Required 100-Year+ WQCV Volume= 15059 (ft) 0.346 (ac-ft) 100-Year+ WQCV Water Surface Elevation = 4911.04 ' Total Pond Volume - 43578 (W) 1.000 (ac-ft) Incremental Volume= Y (ELE, I. 2 - ELEF 1) x ( AREA I + AREA 2 + ( AREA I x .AREA 2) � ) Contour Elevation Contour Area {t3 Volume Cumulative Volume (ft3) Cumulative Volume acre-ft 4909.50 0.0 0 0 0.000 4910.00 3144.6 524 524 0.012 4910.50 12895.3 3735 4259 0.098 4911.00 26342.5 9611 13870 0.318 4911.50 28894.7 13804 27675 0.64 4912.00 34811.8 15904 43578 1.00 SOUTH POND 311012015 8:(17 AM GASCHLAGETER\14.0833-Avago - Building 31ENG\DRAT NAGE\2015.03.07_MI NOR AMENDMENT SUBMITTAL 3\Pond_WSEL.)dsm 1 ' PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT#: POND NAME: NORTH POND ' DATE: ' Water Quality Orifice Plate Design: Equation For 40 Hour Drain Tate : Equation For 72 Hour Drain Time I4" C 17 C ' A=1.8I Q I A=r£UbV�7 b = 0.0166H' +0.2055H +0.1543 b=0.00528Hz+0.0655H+0.0492 c=-0.0018Hz-0.0068H+1.0015 c=-0.0018H2-0.0068H+1.0015 ' 'Figure EDB�3, UDFCD (V.3), Chapter 4, Pa. S-74 `Figure SO-8, UDFCD (10.2), Chapter 10, Pg. SO-37 Where: A= Required Area Per Row (in- ' H = Depth At First Perforation (ft) WQCV = Water Quality Capture Volume (acre-ft) 'WQCV = 0.055 (acre-ft) 'Water Quality WSEL= 4916.50 (it) ' Elevation At First Perforation = 4915.20 (ft) H = 1.30 (ft) b = 0.450 ' C = 0.990 Max Outlet Area Per Row = 0.21 (inz) Hole Diameter = 0.500 (in) ' Actual Outlet Area Per Row = 0.20 (inj Numberof Columns Number of Row4s = 4 Total Outlet Area = 0.79 (in) 'WQCV and WQ WSEL increased for construction tolerance 11 MARTIN /MARTIN Hole Dia (in) Area Per Raw (sq in) n=1 n=2 n=3 0.250 0.05 0.10 0.15 0.313 0.08 0.15 0.23 0.375 0.11 0.22 0.33 0.438 0.15 0.30 0.45 0.500 0.20 0.39 0.59 0.563 0.25 0.50 0.75 0.625 0.31 1 0.61 0.92 0.688 0.37 0.74 1.12 0.750 0.44 0.88 1.33 0.813 0.52 1.04 1.56 0.875 0.60 1.20 1.80 0.938 0.69 1.38 2.07 1.000 0.79 1.57 2.36 1.063 0.89 1.77 2.66 1.125 0.99 1 1.99 2.98 1.188 1.11 2.22 3.33 1.250 1.23 2.45 3.68 1.313 1.35 2.71 4.06 1.375 1.48 2.97 4.45 1.438 1.62 3.25 4.87 1.500 1.77 3.53 5.30 1.563 1.92 3.84 5.76 1.626 2.07 1 4.15 6.22 1.688 2.24 4.48 6.71 1.750 2.41 4.81 7.22 1.813 2.58 5.16 7.74 1.875 2.76 5.52 8.28 1.938 2.95 5.90 8.85 2.000 3.14 6.28 9.42 n = Number of Columns of Perforations -rgure e, uurcu (v.3), chapters, Pepe sn-a NORTH WO ORIFICE PLATE 311012015 11:48 AM G:\SCHLAGETER\14.0933-Avago - Bwlding 3\ENG\DRAINAGE\2015.03.07_MINOR AMENDMENT SUBMITTAL 3\W0_OrificePlate.ads ' PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT M. POND NAME: SOUTH POND ' DATE: Water Quality Orifice Plate Design: Equation For 40 Hour Dram Time : Equation For 72 Hour Drain Time A=1.8I WQCI' j� A=(£URV j7 r b ILL b J b=0.0166H'+0.2055H+0.1543 b=0.00528Xz+0.0655H+0.0492 c=-0.0018H2-0.0068H+1.0015 c=-0.0018 H2-0.0068X+1.0015 -Figure EDt1-3, UOFCD (V.3), Chapter d, Pp. S-74 'Figure SO-8, UDFCD (V.2), Chapter 10, Pg. SO-37 Where: A = Required Area Per Row (in-) ' H = Depth At First Perforation (ft) WQCV = Water Quality Capture Volume (acre-ft) WQCV = 0.078 (acre-ft) Water Quality WSEL = 4910.38 (ft) ' Elevation At First Perforation = 4909.50 (ft) H = 0.88 (it) b = 0.348 ' C = 0.994 Max Outlet Area Per Row = 0.40 (in) Hole Diameter= 0.888 (in) Actual OWet Area Per Row= 0.37 (in') Number Columns Number of Rows =I 7 Total Outlet Area = 1.12 (m2) fl MA RTIN/MARTIN Hole Dia (in) Area Per Row (sq in) n=1 n=2 n=3 0.250 0.05 0.10 0.15 0.313 0.08 0.15 0.23 0.375 0.11 0.22 0.33 0.438 0.15 0.30 0.45 0.500 0.20 0.39 0.59 0.563 0.25 0.50 0.75 0.625 0.31 0.61 0.92 0.688 0.37 0.74 1.12 0.750 0.44 0.88 1.33 0.813 0.52 1.04 1.56 0.875 0.60 1.20 1.80 0.938 0.69 1.38 2.07 1.000 0.79 1.57 2.36 1.063 0.89 1.77 2.66 1.125 0.99 1.99 2.98 1.188 1.11 2.22 3.33 1.250 1.23 2.45 3.68 1.313 1.35 2.71 4.06 1.375 1.48 2.97 4.45 1.438 1.62 3.25 4.87 1.500 1.77 3.53 5.30 1.563 1.92 3.84 5.76 1.625 2.07 4.15 6.22 1.688 2.24 4.48 6.71 1.750 2.41 4.81 7.22 1.813 2.58 5.16 7.74 1.875 2.76 1 .52 8.28 1.938 2.95 5.90 8.85 2,000 1 3.14 6.28 9.42 n = Number of Columns of Perforations -rgum a, .,,w I vat, caaprera, rape aua SOUTH WO ORIFICE PLATE 3/102015 11:48 AM G:\SCHLAGETER\14.0833-Avago- Building 3\ENG\DRAINAGE12015.03.07_MINOR AMENDMENT SUBMITTAL 31W0_OrificePlate.)ds I PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT #: POND NAME: NORTH POND DATE: X-Year Orifice Design: 1IFY47 1- Orifice Equation Q = CA(2gH)os 'Equation SO-15, UDFCD (V 2), Chapter 10, Page SO-20 MARTIN /MARTIN eoneu�nno emm�eewe Q = Flow Rate Through Orifice (cfs) C = Discharge Coefficient (0.40-0.65) A = Area of Orifice (ft2) H = Effective Head On Orifice Opening (ft) g = Gravitational Acceleration (32.2 ft/seC2) Max 100-Year Release Rate = 1.1 (cfs) Water Qaulity WSEL = 4916.50 100-Year WSEL = 4917.25 Orifice Centroid Elevation = 4916.83 H = 0.42 (ft) A = 0.35 (ft2) g = 32.2 (ft/sec2) C = 0.60 (0.40-0.65) Orifice Diameter = 8.02 (in) X-Yr Release (Orifice) G:\SCHLAGETER\14.0833-Avago - Building 3\ENG\DRAINAGE\2015.03.07_MINOR AMENDMENT SUBMITTAL 3\100-YR 3/10/2015 11:52 AM Release Odfice.xlsm i 1 1 1 i 1 1 1 1 PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT#: coARTTNo a TIN oR ewa CALCULATION: SOUTH POND DATE: 3/12/2015 11:09 AM 10- Year Orifice Release at Outlet Structure 10-Year Rectangular Orifice Design: Orifice Equation Q = Cd(2gH Y.5 'Equation SO-15, UDFCD (V2), Chapter 10, Page SO-20 Where: O = Flow Rate Through Orifice (cfs) C = Discharge Coefficient (0.40-0.65) A = Area of Orifice (ft') H = Effective Head On Orifice Opening (ft) g = Gravitational Acceleration (32.2 ft/sec') Max 100-Year Release Rate = 1.60 (cfs) Opening Invert = 4910.50 100 YR WSEL= 4911.25 Orifice Opening Height 0.500 (ft) 6 (in) Orifice Centroid Elevation = 4910.75 H = 0.50 (ft) A = 0.47 (ft') g = 32.2 (ft/seC') C = 0.60 (0.40-0.65) Orifice Length = 0.94 (ft) 11.28 (in) 10-Yr Release (Rect. Orifice) CAUsers\stratmankDesktop\10YR ORIFICE RECTAS i PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT #: POND NAME: NORTH DATE: 03/10/15 .I MARTIN /MARTIN co.eulriNo c'+oinccwe 100-Year Outlet Design Orifice Control Check: Orifice Equation O = C,4(2gH)° `Equation SO-15, UDFCD (V.2), Chapter 10, Page SO-20 Where: Q = Flow Rate Through Orifice (cfs) C = Discharge Coefficient (0.40-0.65) A = Area of Orifice (ft') H = Effective Head On Orifice Opening (ft) g = Gravitational Acceleration (32.2 ft/sec') Max Future 100-Year WSEL =1 4922.30 (Bottom of Proposed Spillway Crest) Inlet Grate Elev. = 4921.30 H = 1.00 (ft) g = 32.2 (ft/sec') C = 0.60 Outlet Type Provided:1 CDOT Type D Inlet Number Of Inlets =� Net Opening Area = 13.5 (ft') NORTH 100-Yr Release G:\SCHLAGETER\14.0833-Avago - Building 3\ENG\DRAINAGE\2015.03.07_MINOR AMENDMENT SUBMITTAL 3\100- 3/10/2015 11:50 AM Year Release.xlsm I! II 11 PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT #: POND NAME: SOUTH DATE: 03/10/15 ./0�MARTIN /MARTIN CONSULTING ENGINEERS 100-Year Outlet Design Orifice Control Check: Where: Orifice Equation Q = CA(2gH)o s 'Equation SO-15, UDFCD (V.2), Chapter 10, Page SO-20 Q = Flow Rate Through Orifice (cfs) C = Discharge Coefficient (0.40-0.65) A = Area of Orifice (ft') H = Effective Head On Orifice Opening (ft) g = Gravitational Acceleration (32.2 ft/secz) Emergency Overflow LP =1 4915.00 Inlet Grate Elev. = 4911.25 H = 3.75 (ft) g = 32.2 (ft/secz) C = 0.60 Outlet Type Provided: COOT Type D Inlet Number Of Inlets =� Net Opening Area = 13.5 (ft2) _ SOUTH 100-Yr Release G:\SCHLAGETER\14.0833-Avago- Building 3\ENG\DRAINAGE12015.03.07 MINOR AMENDMENT SUBMITTAL 3\100- 3/10/2015 11:50 AM Year Release.xlsm PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT #: POND NAME: NORTH DATE: 03110/15 Emergency Overflow Weir Type: I Broad -Crested Cscw = 1 3.00 Broad -Crested Weir 0=CvrwLFT" -Equation SO-18, Page SO-22 Where: ....MARTINLf wn MARTIN O = Discharge (cfs) L = Horizontal Weir Length (ft) H = Head Above Weir Crest Excluding Velocity Head (ft) C = Broad -Crested Weir Coefficient (2.38-3.32) Max 100-Yr Pond Inflow = 34 (cfs) RE: Rational Method, Basin A 0100 Weir Design Release Rate = 34 (cfs) Spillway Crest Elevation = 4922.30 Top of Pond Elevation = 4923.30 Emergency Overflow Weir WSEL Freeboard Required = 0.50 (ft) H= 0.50 (ft) Minimum Crest Length= 32.26 (ft) Crest Length Provided = 100.0 (ft) Discharge Capacity Provided = 105.07 (cfs) Emergency Overflow Weir WSEL at Capacity= 4922.80 (ft) @ 106.07 (cfs) Emergency Overflow Weir WSEL at Design Release Rate= 4922.54 (ft) @ 34.22 (cfs) North Emergency Overflow 3l10I2OG5\SCAWETER\14.0833-Avago - Building 31ENG\DRAINAGE\2015. 03.07_MI NOR AMENDMENT SUBMITTAL 3\Emergency-Overflow Weir.xis II II j I I I I I I I� THIS SHEET PROVIDED TO PROVE NORTH POND CAN DETAIN MORE VOLUME THAN IS REQUIRED IN CASE OF ANY FUTURE IMPROVEMENTS PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT#: POND NAME: NORTH POND DATE: 03/10115 6 3/10/2015 11:57 AM Required Detention Volume: V. = K, A (1.781— 0.0021 z — 3.56) { 10° = 900 (0.951-1.90) {10 1000 ` — (0.771— 2.65) 1000 Where: For Type A Sods : V1,,,,A=(-0.00005501.12+0.030148-1-0.12)..4 12 'Equations SO-1 through SO-5, UDFCD (V2), Chapter 10, Pg. SO-9 V, = Required Volume Where Subscript i = 100-, 10- or 5-Year Storm (acre-ft) K = Empirical Volume Coefficient I = Fully Developed Tributary Catchment Imperviousness (%) A = Tributary Catchment Area (acres) 1= 100.0 (°i°) DETENTION VOLUMES AND A=1 4.50 (acres) RELEASE RATES BASED ON FUTURE DEVELOPMENT ASSUMPTION OF 3.4 K100= 0.172 ADDED IMPERVIOUS ACRES K1°= 0.093 Ks = 0.074 TRIBUTARY TO NORTH POND V1°° = 0.772 (ac-ft) 33,637 1 (cu-ft) V1° = 0.419 (ac-ft) 18,249 (cu-ft) WOCV= 0.225 (ac-ft) 9,801 (cu-ft) V100AE00.997 (ac-ft) 43,438 (cu-k) V1°.aEo = 0.644 (ac-k) 28,050 (cu-ft) NRCS Hydrologic Soil Group: C 8 D Max 5-Year Release Rate = 0.8 (efs) Max 10-Year Release Rate = 1.4 (cfs) Max 100-Year Release Rate = 4.5 (efs) Maximum Unit Flnw Rplpacp Ratpc trfs/arrpl frnm nn-3itp nofunfinn Farilifipe Design Return Period (Years) NRCS Hydrologic Soil Group A B C & D 5 0.07 0.13 0.17 10 0.13 0.23 0.30 100 0.50 0.85 1.00 -i anie au-1uurw iV q. unaprer iU, rage aU-a Detention Volume North G:\.SCHLAGETER\14.0833-Avago-Building 3\ENG\DRAINAGE\FUTURE\DetVol KA.xls I THIS SHEET PROVIDED TO PROVE NORTH POND CAN DETAIN MORE VOLUME THAN IS REQUIRED IN CASE OF ANY FUTURE IMPROVEMENTS PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT#: M/\NI IN MARTIN POND NAME: NORTH POND DATE: 03110115 Required Water Quality Volume = 9801 (ft') 0.225 (aoft) Water Quality Surface Elevation = 4916.77 0 Required 100-Year+ WQCV Volume = 43438 (ft') 0.997 (aoft) 100-Year+ WQCV Water Surface Elevation = 4918.84 Total Pond Volume = 123699 (ft 2.840 (ac-ft) POND WSELS BASED ON FUTURE DEVELOPMENT ASSUMPTION OF 3.4 ADDED IMPERVIOUS ACRES TRIBUTARY TO NORTH POND li Incremental Volume= Y (ELEI. 2 - LLE,T - 1) x (AREA I + AREA 2 + (ARLA I x AREA 2 ) " ) Contour Elevation Contour Area ft' Volume ft' Cumulative Volume (ft') Cumulative Volume acre-ft 4915.20 0.0 0 0 0.00 4916.00 6714.1 1790 1790 0.04 4917.00 14552.3 10384 12174 0.28 4918.00 17254.8 15884 28058 0.64 4919.00 19479.4 18356 46414 1.07 4920.00 21800.1 20629 67043 1.54 4921.00 24233.2 23006 90049 2.07 4921.30 25010.2 7386 97435 2.24 4922.30 27536.4 26263 123699 2.84 NORTH POND 3/10/2015 11:66 AM G:\SCHLAGETER\14.0633-Avago - Building 31ENG\DRAINAGE\FUTURE\Pond_WSEL.,Esm PROJECT INFORMATION PROJECT NAME: AVAGO B3 PROJECT #: POND NAME: NORTH POND DATE: 3/10/2015 100-YEAR RESTRICTOR PLATE THIS SHEET PROVIDED TO PROVE NORTH POND CAN DETAIN MORE VOLUME THAN IS REQUIRED IN CASE OF ANY FUTURE IMPROVEMENTS MARTIN /MARTIN cowwuunNa [Noiwc[ww Max 100-Year Release Rate = 4.50 (cfs) Outlet Pipe Invert Elevation = 4915.20 (ft) MINIMUM 3" BELOW LOWEST PERF. 4917.00 (ft) Inlet Grate Elevation = 4917.00 (ft) 100-Year WSEL = 4918.84 (ft) Orifice Equation: O - ('4 ''-SH 'Equation SO-15, UDFCD (V.2), Chapter 10, Page SO-20 POND OUTLET STRUCTURE OUTLET PIPE DIAMETER SIZED FOR FUTURE DEVELOPMENT ASSUMPTION OF 3.4 ADDED IMPERVIOUS ACRES TRIBUTARY TO NORTH POND O = Flow Rate Through Orifice (cfs) C = Discharge Coefficient (0.40-0.65) A = Area Of Orifice (ft') H = Effective Head On Orifice Opening (ft) g = Gravitational Acceleration (32.2 ft/sec") Minimum Opening Area = 0.51 (ft2) H = 3.35 (ft) g = 32.2 (ft/sec') C = 0.60 (0.40-0.65) Outlet Pipe Diameter = 18 (in) 1.50 (ft) R = 0.75 (ft) 6 = 1.23 (rad) "y" Invert To Plate = 0.50 (ft) = 6.0 (in) A = 0.51 W) A, = R'`(0 — sin 0 cos 91 p=2.10 R _A,.=0—sin a cm. bR V 2B (al Circular channel (8 in rad) Centroid Elevation = 4915.49 (ft) Velocity = 8.81 (ft/s) 1 THE NORTH POND OUTLET STRUCTURE IS ' SIZED SO THAT IN THE CASE OF FUTURE DEVELOPMENTS, ONLY MINOR CHANGES WILL NEED TO BE MADE. THE FRONT TOP OF THE OUTLET STRUCTURE BOX WAS SET ABOVE A FUTURE 100-YR + WQ WSEL AT 4919.00. �i 3/10/2015 11 57 AM 100-Yr Restrictor Plate G:\SCHLAGETER\14.0833-Avago - Building 3\ENG\DRAINAGE\FUTURE\NORTH 100-Year_Release.xlsm I I I I I I 1 a I I I i x I I I X v •� s••ei ••oi iii: • ♦1••a••.1 ��1. s:•1•••f •,1n411 ♦�•••xn ••a. •1 • • • .•': •a•••1.aV a1 i i�•af •e�•�1 1-, NEW PAVEMENT OVER LANDSCAPE ® NEW PAVEMENT (FOR GRADE) NEW PAVEMENT OVER FAILED ASPHALT PROPOSED PAVEMENT AREA ANAL YSIS EXHIBIT FOR USE IN DETERMINING THE REQUIRED AREA OF POROUS PAVEwE;YT PER CITY OF FORT COLLINS CRITERIA, 25% OF NEW PAVEMENT AIUST BE POROUS PAVEMENT Jj f—r� �'i, A'/ PROPOSED PAVEMENT OVER LANDSACAPE 76,620 SF (1.76 AC) • 25% PAVERS: 19,155 SF (0.44) POTENTIAL NEW PAVEMENT OVER FAILED EXISTING ASPHALT AREA: 1* 25 SF ERR: AC) I • 25% PAVERS: 10,850 SF (0.25 AC) ADDITIONAL POTENTIAL NEW PAVEMENT AREA: 72,038 SF (1.65 AC)� • 25% PAVERS: 18,010 SF (0.41 AC) M REQUIRED POROUS PAVEMENT (25% OF TOTAL NEW PAVEMENT) = 48,015 SF (1.10 AC) I 1 I�l Q? -1P I = I ZU 1/2015 MARTIN/MARTIN 40000 CONSULTING ENGINEERS 12499 WEST COLFAX AVENUE, LAKEWOOD, COLORADO 80215 303.431.6100 MARTINMARTIN.COM I c �a an ti•'•iys", POROUS PAVERS (22,639 SF) \ %//�//////i///i/i//i////j POROUS PAVERS (1.866 SF)� ,N7 / POROUS PAVERS (1,354 SF) POROUS PAVERS (6,104 SF) POROUS PAVERS (4,745 SF) 7% Building 4 West Annex 25' bldg setback . `. Buildii+ 3-' 50' bldg setback POROUS PAVERS (11,010 SF) POROUS PAVERS (3,966 SF) � ' 77 1 petention �%' ' Pond '_ ji ► POROUS PAVERS (TOTAL 51,684 SF 1.19�AC) �•,�� REQ'D POROUS PAVERS: 48,015 SF 'Z ADDITIONAL POROUS PAVERS: 3,669 SF FUTURE PAVEMENT DEVELOPMENT f & 'Cl 14,676 SF ' I • . �Y. I I . N' Y -- • All -III PROVIDED POROUS PAVEMENT AREA ANsALYSIS EXHIBIT {LiI TO SHOW COMPLIANCE WITH CITY OF FORT COLLINS LID CRITERIA AND n PROVIDE DOCUMENTATION TO THE EFFECT THAT THE AVAGO Building PROPERTY WILL CARRYA PAVEMENT DEVELOPMENT CREDIT OF 14,676 `PAVEMENT DEVELOPMENT CREDIT'MEANS THAT THE AVAGO CAMPUS PROPERTY WILL REMAIN IN COMPLIANCE WITH THE CITY'S LID CRITERIA FOR PAVEMENT DEVELOPMENT AFTER UP TO 14,676 SF OF --FUTURE NON -POROUS PAVEMENT AREA HAS BEEN ADDED TO THE SITE (AND WITHOUT PROVIDING ADDITIONAL POROUS PAVEMENT). Building Z' f It MARTIN/MARTIN all CONSULTING ENGINEERS 12499 WEST COLFAX AVENUE, LAKEWOOD, COLORADO 80215 303.431.6100 MARTINMARTIN.COM 11 I 11 I 1 1 1 I I V II I i r I I RUN-ON AREA (27,895 SF) RUN-ON AREA (1,452 SF) RUN-ON AREA (572 SF): RUN-ON AREA (57,841 SF) �\ f 0 POROUS PA VEMENT RUN-ON EXHIBIT �_✓ / `�/ / RUN-ON AREA (1,998 SF) II RUN-ON AREA (2,226 SF) i ,O liV�l 1 L J ab. 0 RUN-ON AREA (7,204 SF)71 / _ AREA THAT RUNS ON TO POROUS PAVERS AREA 99,188 SF 2.28 AC) r-I / MARTIN/MARTIN _� CONSULTING ENGINEERS 12499 WEST COLFAX AVENUE, LAKEWOOD, COLORADO 80215 � 303.431.6100 MARTINMARTIN.COM I @ 0. � LA k z 2 ) � § $ \ < # 't kR«� 00 � § ev k kR o Ln r4 _ K f rn 2 2 ¥ 2 2 2 a a qq�'t q A q -0 _ _ � m _ _ m 5 5& a LU Z U2 cc LU / / kLU \ �o� F �� a� # k\ k 5 §� K 5 }�) �K 0K » b § g S § c k 2 o cr o § § z 2 ° // q �9L r °§ ■ z w ° § § in k / o j �f §$ / [ co z LU LU z �■ z z x LU LU j cc cc § cc Ne \ g © f � � § / 0 0 LAJ LU > g o § z m $ § o w cr m u cr � k co } \ / cc « A k LU ® o = k § \§\ �2§ ° ) § § o o / $ « u < \ M LL 2 § / k § ° z ( § L UJ § \ [ _ « u o m o < § 2 # k § § � k \ k kn\ §LU z§� § § § LU LU § 2 § § \ o �� @ w / § / k K § II I I I DRAINAGE PLAN I I I 11 _ \ PROPty-1' LINE PROPOSED cuTLET1 SRUC1TIP POND MANILNANTi A.,cE ,. _ —1 PROPOSED STORM UNE H JI Ir � ■ _ atvnr Ot 7 1 M1'N 4lk4923 PROPOSED NORTH POND PROPOSED STORM LINL G I) '1 I III' 2I r I ° x,I p � Al ■ 6.1 03 I ■ 04 PROPOSED STORM 1 I �� __ I I � NORTH POND SUMMARY TABLE 100—YR TOTAL TOTAL 100—YR + CALCULATED PROVIDED TOP OF SPILLWAY POND MAX 100—YR DETENTION WQCV REQUIRED VOLUME WOCV WSEL WQCV WSEL WQCV WSEL POND CREST ELEV. FREEBOARD RELEASE VOLUME VOLUUME PROVIDED 0.182 AC TO DOES AC -Fr 0.242 AC -FT (10D-YR + ISO" 2.84 IC -FT O M - 4922.15 4916.84 4916.06 4917.25 492330 4922.30 1'-0. 1.09 CPS SOUTH POND SUMMARY TABLE 100YR TOTAL TOTAL 100-YR + CALCULATED PROVIDED TOP OF !POND SPILL POND 100-YR DETENTION WQCV REWIRED VOLUME WQCV WSEL WQCV WSEL WQCV WSEL POND ELEV. FREEBOARD RELEASE VOLUME VOLLUME PROVIDED 0.288 AC FT 0.078 AC-FT (100-TR i WQCV) -� 1.00 AC -FT 4911,04 4910.34 4910.50 4912.33 4911.50 V-0' 1.56 CPS ■ I1!\UNOERORNN (Trot_ - 4922 I M 1 �� V I o- I w �/1(—•ago a tl ! 1 �4'AZ. b ? m I -Dl {. _1 PRO �D. AREA I,, I i L� 19 V INLET (lYP) I PROPLrz'v rNL M � ■ "n i 4- PROPOSED ROOF y% / d± : *. PROPOSED U DRAIN ( P) T BUILDING DZ -4921.00 II IY / / i / '/� ( B] FF=4918.00 �� B1 1 (/I 4920- 2 7 - �`. COURTYARD EMERGENCY I 4 OVERFLOW PATH. (2) 3' WIDE N tI. - WAREHOUSE a 1' HIGH BOX CULVERTS ' ■ F / ( e e FF=4921.00 yUNDER BUILDING CONNECTION ■ I'PNPSF�� ( �- w DRAINAGT snr.r I' / / / / / Is t PROPOSED PROPOSED STORM LINE F PROPOSED STORM nvC c _ TRENCH DRAIN (EMERGENCY OVERFLOW PIPE) ( D3dIL B I PROPOSED POROUS PROPOSFD APIA. IFAVERS (iW) C1 DEAN (rvP` _ PROPOSED STORM LINE E r. s :A i ]"9 042 .1 POND MAINTENANCE O. ACCESS {I, a—PCOFOSED STORM LINE A PROPOSED �,SOUNI POND N $ PROPOSED STORM MANH LL PIP-) \lr\ IIF, -PROPOSED STORM LINE O PROPOSED CURB INLET (TP) G� I //G ti ,! �R l— CONNECT TO EXISTING O �/J N 36" STORM SEWER Lilli - - D4 sin, e e R ., 1 645 �" -974 • EW R N I :IG 0t � U ne PROP`RTY LINE 1 BASIN POIM C— I_MESI MP. CIO C,rt. (CF6j I CFBma I An Al a18 194% Fall 032 108] 25R A2 A2 1.11 '3 Ya aW 084 420 901 B1 51 317 49 TD 057 061 859 18 76 02 62 255 K3% 067 073 8.10 1802 C1 C1 ]93 338% 042 046 15111 353E 01 D1 103 521% 059 063 285 628 D2 D2 2J6 4WSO 052 0% 583 1282 D3 D3 020 036% 0.as 0.% 2.90 042 CA 34 1 is 371% 045 049 253 564 LEGEN BASIN BOUNDARY mosenew DIRECTION OF FLOW y DESIGN POINT Q BASIN B c10 2 AREA IN .e CIOO ACRES RFNCHMARK NM29 UNADJUSTED (DIED CITY OF FORT COLLINS DATUM) PROJECT DATUM: BENCHMARK /r 6 Ol' CITY OF FORT COLLINS VERTICAL CONTROL, SE CORNEIR INTERSECTION OF ZIEGLER RD B HARMONY RD (N:B569.0]8 E1010394) ELEVATiION 492T 89 BENCHMARK pT i-olo CITY OF FORT COLLINS VERTICAL CONTROL, NORTH SIDE OF HARMONY ROAD ON AN IRRIGATION STRUCTURE APPROWIMATELY 10OFT WEST OF THE WEST CURB ONE AT THE EAST EMWUICE TO H.P. (N 820506 E:12512.77B) ELEVATIION AST 1.33. NOTE: ^ IF MW88 DATUM IS REQUIRED FOR ANY PURPOn THE FOLLOWING EQUATION SHOULD BE USED: NAVDBB NGVD29 UNADJUSTED + 3.02. RAC14 OF BEARINGS THE H. R UNE OF THE SOUTHWEST QUARTER OF FOUND AIJ 33, TOWNSHIP NORTH. RANGE 6B WEST. TER CO NTED BY A FOUND ALUI2INUM CAP (LS BRKSS AT THE WEST QUARTER CORNER W A FOUND IMPNE COUNTY S BRA$$ LAP AT THE SOUTHWEST CORNER WITH A ONE BETWEEN ASSUMED i0 BEAR SOUTH GO 00' 07' WEST. l N I sew 3 00' G 1t -i US SUM EMT KEYMAP N.T.S. LEGE D PROPOSED PROPERTY LINE — - - — - - - RIGHT-OF-WAY LINE — - - - — SECTION UNE EASEMENT — — — — — RETNNING WALL CURB h GUTTER ---- -" CONTOURS 5750-- -- - STORM SEWER —ST UNDER DRAIN — UDC STORM MANHOLE O ROOF DRAIN 0 INLET FLARED END SECTION cc ^ SIGN i - e GRADING ARROW �) DECIDUOUS TREE O Ail EVERGREEN TREE Q BUSH/SHRUB ORILC DESCRIPTIONS DRIVE d SPOT ELEVATIONS •WIN CALL 811 2-BUSINESS DAYS IN ADVANCE BEFORE YOU DIG GRADE OR EXCAVATE FOR MARKING OF UNDERGROUND MEMBER UDLIRES MARTIN/MARON ASSUMES NO RESPONSIBILITY FOR UTILITY LOCATIONS. THE UTILITIES SHOWN ON THIS DRAWING HAVE BEEN PLOTTED FROM THE BEST AVAILABLE INFORMATION. R IS, HOWEVER, THE CONTRACTORS RESPONSIBILITY TO FIELD VERIFY THE SIZE, MATERIAL, HORIZONTAL AND VERTICAL LOCATION OF ALL UTILITIES PRIOR TO THE COMMENCEMENT OF ANY CONSTRUCTION. City of Fort Collins, Colorado UTILITY PLAN APPROVAL APPROVED: 'Y nLT�nee� 1f-1 CHECKED BY:Va7e-rTTIT15y �� CHECKED BY: � r Y CHECKED TOa . e acres on CHECKED BY: mat— ra c nTi� CHECKED BY. 15-01 T400 East Orchard Rd IOreenwood Allege. ( (303)504-9999 wwwAINICPlgra 0 MAZZETTI LW9 KI Sort s,la 450 M ,, CowM µrr„waom PROJECTNUMBER: 1u075 ;KE=MIEE WRE 11Iore0x Was i)m':W WX+YS4Ni*1RlG<rM Avaoo T E C H N O L O G I EB BUILDING 3 MINOR AMENDMENT-150006 4IUM ZIEGLER ROAD Fr. COLLINS, COLORADO 80M DRAINAGE PLAN Job No. 10.0B3J De■ OLH.15 Dream By M. CNAPA CIIIaNee By P. BUCKLEY SHEET NO. D100 sI� ASSHOWN