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HomeMy WebLinkAboutLANDMARK RESIDENCES ON MOUNTAIN AVENUE - FDP - FDP150019 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTFINAL DRAINAGE REPORT Landmark Residences on Mountain Avenue Fort Collins, Colorado May 6, 2015 Prepared for: Savant Homes Inc. P.O. Box 2066 Fort Collins, CO 80522 Prepared by: 301 North Howes Street, Suite 100 Fort Collins, Colorado 80521 Phone: 970.221.4158 Fax: 970.221.4159 www.northernengineering.com Project Number: 1022-001 P This Drainage Report is consciously provided as a PDF. Please consider the environment before printing this document in its entirety. When a hard copy is absolutely necessary, we recommend double-sided printing. May 6, 2015 City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, Colorado 80521 RE: Final Drainage Report for Landmark Residences on Mountain Avenue Dear Staff: Northern Engineering is pleased to submit this Preliminary Drainage and Erosion Control Report for your review. This report accompanies the 12.17.14 Preliminary Development Review submittal for the proposed Landmark Residences on Mountain Avenue. Comments from the Preliminary Review Letter dated October 28, 2014 have been addressed. Written responses thereto can be found in the comprehensive response to comments letter on file with Current Planning. This report has been prepared in accordance to Fort Collins Stormwater Criteria Manual (FCSCM), and serves to document the stormwater impacts associated with the proposed Landmark Residences on Mountain Avenue project. We understand that review by the City is to assure general compliance with standardized criteria contained in the FCSCM. If you should have any questions as you review this report, please feel free to contact us. Sincerely, NORTHERN ENGINEERING SERVICES, INC. Bud Curtiss, PE Cody Snowdon Project Manager Project Engineer Landmark Residences on Mountain Avenue Preliminary Drainage Report TABLE OF CONTENTS I. GENERAL LOCATION AND DESCRIPTION ................................................................... 1 A. Location ....................................................................................................................................... 1 B. Description of Property ................................................................................................................ 2 C. Floodplain .................................................................................................................................... 3 II. DRAINAGE BASINS AND SUB-BASINS ....................................................................... 5 A. Major Basin Description ............................................................................................................... 5 B. Sub-Basin Description .................................................................................................................. 5 III. DRAINAGE DESIGN CRITERIA ................................................................................... 5 A. Regulations .................................................................................................................................. 5 B. Four Step Process ........................................................................................................................ 5 C. Development Criteria Reference and Constraints ......................................................................... 6 D. Hydrological Criteria .................................................................................................................... 6 E. Hydraulic Criteria ......................................................................................................................... 7 F. Floodplain Regulations Compliance .............................................................................................. 7 G. Modifications of Criteria .............................................................................................................. 8 IV. DRAINAGE FACILITY DESIGN .................................................................................... 8 A. General Concept .......................................................................................................................... 8 B. Specific Details ........................................................................................................................... 10 V. CONCLUSIONS ...................................................................................................... 10 A. Compliance with Standards ........................................................................................................ 10 B. Drainage Concept ...................................................................................................................... 11 References ....................................................................................................................... 12 APPENDICES: APPENDIX A – Hydrologic Computations APPENDIX B – Hydraulic Computations B.1 – Storm Sewers B.2 – Inlets APPENDIX C – Water Quality Design Computations APPENDIX D – Floodplain Regulations Quick Guide APPENDIX E – Erosion Control Report APPENDIX F – NRCS Soils Report Landmark Residences on Mountain Avenue Preliminary Drainage Report LIST OF TABLES AND FIGURES: Figure 1 – Aerial Photograph ................................................................................................ 2 Figure 2– Proposed Site Plan ................................................................................................ 3 Figure 3 – Existing City Floodplains ....................................................................................... 4 MAP POCKET: C400 - Drainage Exhibit Landmark Residences on Mountain Avenue Preliminary Drainage Report 1 I. GENERAL LOCATION AND DESCRIPTION A. Location 1. Vicinity Map 2. Landmark Residences on Mountain Avenue project is located in the southwest quarter of Section 11, Township 7 North, Range 69 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. 3. The project site is located northeast corner of Shields Street and Mountain Avenue. 4. Currently the existing lot does not have any stormwater or water quality facilities. The project consists of a gas station and convenient store. The store is currently surround on all sides by asphalt parking and drives. The remaining area consists of landscaping. The project site is composed of 80% imperviousness and have been paying impacts fees at a factor of 0.8. The existing site drains in three direction. The northeastern corner of the existing site drains northeast into the existing public alley. The northwestern and western portion of the existing site drains directly into Shield Street, where it is intercepted by a combination inlet. The southern portion of the existing site drains directly into Mountain Avenue, where it continues west with the public street. 5. The project is currently border to the south by a Mountain Avenue, west by Shields Street, north by a single-family residence and a public alley and east by a single- family residence. Landmark Residences on Mountain Avenue Preliminary Drainage Report 2 B. Description of Property 1. Landmark Residences on Mountain Avenue is approximately 0.62 net acres. Figure 1 – Aerial Photograph 2. Landmark Residences on Mountain Avenue consists of an irregular lot with one convenient store, three gas pump stations and associated drive and parking areas. The remainder of the lot consists of landscape areas and tree lawns. The existing lot drains in three different directions, north into the public alley, east into Shields Street and south into Mountain Avenue. 3. According to the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Soil Survey, 100 percent of the site consists of Fort Collins loam, which falls into Hydrologic Soil Groups C. 4. The proposed development will include the demolition of the existing store and gas facilities, as well as all of the existing drive aisle and parking areas. The entrance from Mountain Avenue will be completely removed, while the entrance from Shields Street will be relocated further to the north. The proposed site will include one main building that will consist of six residential units and one commercial unit. Other structures proposed with this project are nine (9) garage units and a trash enclosure located in the northwestern corner of the site. There is a proposed access drive connecting between Shields Street and the public alley. This access drive consists of both concrete and pavers and will supply access to the garage structures, trash enclosure and additional parking areas. The section of drive constructed of permeable pavers will act as the projects water quality. Landmark Residences on Mountain Avenue Preliminary Drainage Report 3 Figure 2– Proposed Site Plan 5. There is an existing private irrigation system located on site. This system irrigates the front tree lawns located along the frontage of Shields Street and Mountain Avenue. 6. The project site is within the Low Density Mixed-Use Neighborhood (LMN) Zoning District. The proposed project is not requesting a change in the land use. C. Floodplain 1. The subject property is not located in a FEMA regulatory floodplain, but is located within a City regulatory floodplain. 2. The FEMA Panel 08069C 0978G, shown below, illustrates that the proposed project is not within a FEMA regulatory floodplain. Figure 4 illustrates that the proposed project is within a City of Fort Collins regulatory floodplain. It is noted that the vertical datum utilized for site survey work is the City of Fort Collins Benchmark #3- 08 (Elevation = 5030.29, NAVD 88) Landmark Residences on Mountain Avenue Preliminary Drainage Report 4 Figure 3 – Existing FEMA Floodplains Figure 4 – Existing City Floodplains Landmark Residences on Mountain Avenue Preliminary Drainage Report 5 II. DRAINAGE BASINS AND SUB-BASINS A. Major Basin Description 1. Landmark Residences on Mountain Avenue is located within the Old Town Basin, which is located primarily in Old Town Fort Collins. B. Sub-Basin Description 1. The property historically drains in three directions and is broken up into three historic basins. Due to improvements proposed to the public alley, drainage within this area is also being evaluated. Within including the public alley, the existing site was broken up into four historic basins. Basin H1 includes a small portion of the existing alley and drains stormwater via overland flow into Shields Street (0.02 cfs for the 2-year storm and 0.08 cfs for the 100-year event). Basin A2 consists of the northeastern corner of the site and the remaining alley. Stormwater from this basin is routed via overland flow and discharges east within the alley (0.48 cfs for the 2-year storm and 2.09 cfs for the 100-year event). Basin H3 consist of the western half of the site and routes stormwater via overland flow into Shields Street (0.54 cfs for the 2-year storm and 2.36 cfs for the 100-year event) where it is combined with runoff from basin H1. All runoff from those two basins are intercepted by an existing inlet within Shields Street. Basin H4 consist of the southeastern portion of the site and routes stormwater via overland flow into Mountain Avenue (0.57 cfs for the 2-year storm and 2.26 cfs for the 100-year event). Runoff from this basin continues east within Mountain Avenue. A more detailed description of the projects proposed drainage patterns follows in Section IV.A.4., below. 2. No drainage is routed onto the property from the east, west, north or south. III. DRAINAGE DESIGN CRITERIA A. Regulations There are no optional provisions outside of the FCSCM proposed with the Landmark Residences on Mountain Avenue Project B. Four Step Process The overall stormwater management strategy employed with the Landmark Residences on Mountain Avenue project utilizes the “Four Step Process” to minimize adverse impacts of urbanization on receiving waters. The following is a description of how the proposed development has incorporated each step. Step 1 – Employ Runoff Reduction Practices Several techniques have been utilized with the proposed development to facilitate the reduction of runoff peaks, volumes, and pollutant loads as the site is developed from the current use by implementing multiple Low Impact Development (LID) strategies including: Providing vegetated open areas along the west and south portion of the site to reduce the overall impervious area and to minimize directly connected impervious areas (MDCIA). Providing permeable paver areas with a water quality section to increase the time of concentration promote infiltration and provide water quality. Landmark Residences on Mountain Avenue Preliminary Drainage Report 6 Routing runoff from the proposed roofs into grass lawn areas. Step 2 – Implement BMPs That Provide a Water Quality Capture Volume (WQCV) with Slow Release The efforts taken in Step 1 will facilitate the reduction of runoff; however, this development will still generate stormwater runoff that will require additional BMPs and water quality. Stormwater generated from the southern portion of the building will be routed across established grass lawns. Stormwater generated from the northern portion of the building will be routed across the proposed access drive into a proposed section of permeable pavers. Step 3 – Stabilize Drainageways As stated in Section I.B.5, above, there are no major drainageways in or near the subject site. While this step may not seem applicable to Landmark Residences on Mountain Avenue, the proposed project indirectly helps achieve stabilized drainageways nonetheless. Once again, site selection has a positive effect on stream stabilization. By repurposing an already developed, under-utilized site with existing stormwater infrastructure, combined with LID, the likelihood of bed and bank erosion is greatly reduced. Furthermore, this project will pay one-time stormwater development fees, as well as ongoing monthly stormwater utility fees, both of which help achieve Citywide drainageway stability. Step 4 – Implement Site Specific and Other Source Control BMPs. This step typically applies to industrial and commercial developments. Because there is a commercial component to the multi-use building the following site specific source control has been included: A localized trash enclosure located in the northwest corner of the property for the disposal of commercial and residential waste. C. Development Criteria Reference and Constraints 1. There are no known drainage studies for the existing properties. 2. There are no known drainage studies for any adjacent properties that will have any effect on the Landmark Residences on Mountain Avenue project. 3. The subject property is essentially an "in-fill" development project as the property is surrounded by currently developed properties. As such, several constraints have been identified during the course of this analysis that will impact the proposed drainage system including: Existing elevations along all property line will be maintained. Existing elevations and vegetation on the south and west side of the subject property will be preserved. As previously mentioned, overall drainage patterns of the existing site will be maintained. D. Hydrological Criteria 1. The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in Figure RA-16 of the FCSCM, serve as the source for all hydrologic computations associated with the Regency Lakeview development. Tabulated data contained in Landmark Residences on Mountain Avenue Preliminary Drainage Report 7 Table RA-7 has been utilized for Rational Method runoff calculations. 2. The Rational Method has been employed to compute stormwater runoff utilizing coefficients contained in Tables RO-11 and RO-12 of the FCSCM. 3. The Rational Formula-based Modified Federal Aviation Administration (FAA) procedure has been utilized for detention storage calculations. 4. Three separate design storms have been utilized to address distinct drainage scenarios. A fourth design storm has also been computed for comparison purposes. The first design storm considered is the 80th percentile rain event, which has been employed to design the project’s water quality features. The second event analyzed is the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The third event considered is the “Major Storm,” which has a 100-year recurrence interval. The fourth storm computed, for comparison purposes only, is the 10-year event. 5. No other assumptions or calculation methods have been used with this development that are not referenced by current City of Fort Collins criteria. E. Hydraulic Criteria 1. As previously noted, the subject property historically drains into the public alley, Shields Street and Mountain Avenue. The majority of the site drains stormwater via overland flow. 2. All drainage facilities proposed with the Landmark Residences on Mountain Avenue project are designed in accordance with criteria outlined in the FCSCM and/or the Urban Drainage and Flood Control District’s (UDFCD) Urban Storm Drainage Criteria Manual. 3. As stated in Section I.C.1, above, the subject property is located within a FEMA and City regulatory floodplain. All design shall be in conformance with Chapter 10 of City Municipal Code. 4. The Landmark Residences on Mountain Avenue project does not propose to modify any natural drainageways. F. Floodplain Regulations Compliance 1. The placement of fill and the construction of new residential dwellings (including mixed-use development) is allowed in the Old Town 100-yr flood fringe. The City of Fort Collins has prepared a Quick Guide for all floodplain regulations other than the Poudre River. This document helps to clearly depict and explain the code allowance to fill in the flood fringe. A copy of this Quick Guide is included in Appendix D for reference. 2. No floodplain modeling is required as part of this proposed development, as it will result in no change to the FEMA regulatory mapped flood hazard zones. However, a City of Fort Collins Floodplain Use Permit, along with ancillary support documents, will be required for the structure and each site construction element (stormwater swale and pond, paths, parking lots, streets, utilities, etc.) in the floodplain. Furthermore, FEMA Elevation Certificates shall be completed and approved before the Certificates of Occupancy are issued the building. 3. A portion of the 100-yr flood fringe encroaches on to the proposed property. No structures are proposed within the floodway. The entire building is located within the 100-year Floodplain. There will be no basements or crawl spaces associated with the structure. All building foundations will be slab-on-grade with thickened perimeter Landmark Residences on Mountain Avenue Preliminary Drainage Report 8 footings (Figure 5). All construction within the floodplain shall be in compliance with Chapter 10 of the City of Fort Collins Municipal Code. Specifically, the Lowest Floor and all HVAC equipment shall be elevated above the Regulatory Flood Protection Elevation. This building is explicitly prohibited from being converted to critical facilities, as defined by Chapter 10 of the City Code. 4. The controlling Base Flood Elevation (BFE) for the commercial unit is 5022.99 feet (NAVD 88), and for the residential units is 5022.87 feet (NAVD 88). The Regulatory Flood Protection Elevation is eighteen (18) inches above the Old Town BFE. The consequent Regulatory Flood Protection Elevation for the commercial unit is 5024.48 feet, NAVD 88 and the Regulatory Flood Protection Elevation for residential units is 5024.37 feet, NAVD 88. Figure 5 – Regulatory Flood Protection Elevations 1. As previously mentioned, all structures are located outside of any FEMA 100-year floodplain, and thus are not subject to any FEMA floodplain regulations. G. Modifications of Criteria 1. The proposed Landmark Residences on Mountain Avenue development is not requesting any modifications to criteria at this time. IV. DRAINAGE FACILITY DESIGN A. General Concept 1. The main objectives of the Landmark Residences on Mountain Avenue drainage design are to maintain existing drainage patterns and ensure no adverse impacts to any adjacent properties. 2. The existing site does not have any off-site runoff that flows onto or through the proposed project. 3. A list of tables and figures used within this report can be found in the Table of Contents at the front of the document. The tables and figures are located within the sections to which the content best applies. 4. The Landmark Residences on Mountain Avenue project is composed of five major Landmark Residences on Mountain Avenue Preliminary Drainage Report 9 drainage basin, designated as Basins A, B, C, D and OS. The project further subdivided Basin OS into four sub-basins, OS1-OS4. The drainage patterns anticipated for these basins and associated sub-basins are further described below. Basin A Sub-basin A1 consists primarily of the proposed alley and the drive entrance to the north. Runoff from both the proposed alley drains via overland and gutter flow. Runoff from the proposed northern entrance drains via overland flow and is combined with the alley drainage within a graded depression located east of the entrance. The minor storm from this sub-basin is designed to be captured by a proposed storm line and routed to the existing inlet within Shields Street, while the major storm will overtop and be routed down the public alley as historically routed. Basin B Sub-basin B1 consists of a portion of the northern drive aisle, northern parking and the northern garages. Runoff from this sub-basin drains via overland and gutter flow to a proposed inlet within the paver system, which drains to the existing inlet within Shields Street. The inlet and storm system is design to capture the minor storm from this sub-basin, while the major storm will overtop the high point within the drive aisle and drain into Sub-basin A1. Basin C Sub-basin C1 consists of consists of the east-west drive aisle, northern half of the proposed building and all of Shields Street frontage. Runoff from this sub-basin drains via overland flow. Runoff from this sub-basin is proposed to drain to Shields Street and captured by the existing inlet located at the intersection of Shields Street and Mountain Avenue. The drainage from the drive aisle and the northern half of the buildings will be routed over the proposed pavers into a proposed inlet along the northern curb and gutter. The inlet and storm system is designed to capture and route the minor storm, while the major storm will overtop the western drive aisle and enter into Shields Street. Basin D1 Sub-basin D1 consists of southern half of the proposed building and frontage along Mountain Avenue. Runoff from this basin drains via overland flow into Mountain Avenue. Basin OS Sub-basin OS1 consists of a small portion of the alley located at the western entrance. This basin drains via overland flow and discharges into Shields street. Sub-basin OS2 consists of a small landscape area located west of the proposed parking stall and drains via overland flow. Sub-basin OS3 consists of a small landscape area located to the east of the proposed building and garages and drains via overland flow. Sub-basin OS4 consists of a small portion of the alley located at the eastern edge of the project limits. This basin drains via overland flow and continues to route runoff down the public alley. Landmark Residences on Mountain Avenue Preliminary Drainage Report 10 A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of this report. B. Specific Details 1. The main drainage problem associated with this project site is the deficiency of water quality present within the existing site. Currently the entire site drains overland and discharges directly into the Shields, Mountain and the public alley without water quality. The proposed site will mitigate this issue by instituting the following water quality devices: All of the runoff generated from the proposed building will be routed through a landscape area. The majority of the on-site improvements generated from the site will be routed through a permeable paver system. 2. The project is located within the Old Town Master Drainage Basin, which does not require detention as long appropriate stormwater impact fees have been paid and the proposed development is less impervious than the existing site. Currently the existing site is paying stormwater impact fees at a factor of 0.8 and has an overall percent impervious of 80 percent. The proposed development has an overall percent impervious of 65 percent, decreasing the percent impervious by 15 percent. This will also reduce the amount of runoff released from the proposed site. 3. There are Nyloplast Drain Basins located within the drive aisle and within the green belt south of the proposed alley are designed to capture the minor storm events from sub-basins A1, B1 and C1, while overtopping the major storm event. Sub-basin A1 will overtop into the public alley. Sub-basin B1 while overtop directly into sub-basin A1. Sub-basin C1 will overtop into Shields Street. Both sub-basins A1 and B1 will route the major storm as historically routed through the public alley. Sub-basin C1 will route the major storm as historically routed into Shields Street. 4. The emergency spillway will be located at the same locations as specified over to route the major storm event. Weir calculations are attached and only account for the area directly above the inlet. More capacity is available along the entire section of the curb and gutter. V. CONCLUSIONS A. Compliance with Standards 1. The drainage design proposed with the Landmark Residences on Mountain Avenue project complies with the City of Fort Collins’ Stormwater Criteria Manual. 2. The drainage design proposed with the Landmark Residences on Mountain Avenue project complies with the City of Fort Collins’ Master Drainage Plan for the Old Town Basin. 3. The drainage design proposed with the Landmark Residences on Mountain Avenue project complies with Chapter 10 of the City of Fort Collins Municipal Code. 4. The drainage plan and stormwater management measures proposed with the Landmark Residences on Mountain Avenue development are compliant with all applicable State and Federal regulations governing stormwater discharge. Landmark Residences on Mountain Avenue Preliminary Drainage Report 11 B. Drainage Concept 1. The drainage design proposed with this project will effectively limit potential damage associated with its stormwater runoff. Landmark Residences on Mountain Avenue decrease in the overall runoff generated from the proposed site. The runoff routed into the existing public alley is less than historic. 2. The proposed Landmark Residences on Mountain Avenue development will not impact the Master Drainage Plan recommendations for the Old Town major drainage basin. Landmark Residences on Mountain Avenue Preliminary Drainage Report 12 References 1. City of Fort Collins Landscape Design Guidelines for Stormwater and Detention Facilities, November 5, 2009, BHA Design, Inc. with City of Fort Collins Utility Services. 2. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No. 174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code. 3. Larimer County Urban Area Street Standards, Adopted January 2, 2001, Repealed and Reenacted, Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007. 4. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation Service, United States Department of Agriculture. 5. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008. 6. Flood Insurance Rate Map (FIRM) Panel 0978G, Revised Date May 2, 2012, Federal Emergency Management Agency (FEMA). 7. Fort Collins Municipal Code (Chapter 10 – Flood Prevention and Protection), 1987, Colorado Code Publishing Company, Fort Collins, Colorado. Landmark Residences on Mountain Avenue Preliminary Drainage Report 13 APPENDIX A HYDROLOGIC COMPUTATIONS Landmark Residences on Mountain Avenue CHARACTER OF SURFACE: Runoff Coefficient Percentage Impervious Project: 1032 W. Mountain Streets, Parking Lots, Roofs, Alleys, and Drives: Calculations By: C. Snowdon Asphalt ……....……………...……….....…...……………….………………………………….0.. 95 100% Date: Concrete …….......……………….….……….………………..….………………………………… 0.95 90% Gravel ……….…………………….….…………………………..……………………………….0.. 50 40% Roofs …….…….………………..……………….…………………………………………….. 0.95 90% Pavers…………………………...………………..…………………………………………….. 0.40 22% Lawns and Landscaping Sandy Soil ……..……………..……………….…………………………………………….. 0.15 0% Clayey Soil ….….………….…….…………..………………………………………………. 0.25 0% 2-year Cf = 1.00 100-year Cf = 1.25 Basin ID Basin Area (s.f.) Basin Area (ac) Area of Asphalt (ac) Area of Concrete (ac) Area of Roofs (ac) Area of Gravel (ac) Area of Lawns and Landscaping (ac) 2-year Composite Runoff Coefficient 10-year Composite Runoff Coefficient 100-year Composite Runoff Coefficient Composite % Imperv. H1 631 0.014 0.00 0.00 0.00 0.01 0.00 0.46 0.46 0.58 36% H2 9442 0.217 0.14 0.00 0.01 0.06 0.02 0.78 0.78 0.97 77% H3 10397 0.239 0.14 0.03 0.02 0.00 0.05 0.80 0.80 1.00 79% H4 9897 0.227 0.10 0.10 0.01 0.00 0.02 0.88 0.88 1.00 86% Total 30367 0.697 0.38 0.14 0.03 0.07 0.08 0.81 0.81 1.00 80% HISTORIC COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS Notes December 17, 2014 10-year Cf = 1.00 Landmark Residences on Mountain Avenue Overland Flow, Time of Concentration: Project: 1032 W. Mountain Calculations By: Date: Gutter/Swale Flow, Time of Concentration: Tt = L / 60V Tc = Ti + Tt (Equation RO-2) Velocity (Gutter Flow), V = 20·S½ Velocity (Swale Flow), V = 15·S½ NOTE: C-value for overland flows over grassy surfaces; C = 0.25 Is Length >500' ? C*Cf (2-yr Cf=1.00) C*Cf (10-yr Cf=1.00) C*Cf (100-yr Cf=1.25) Length, L (ft) Slope, S (%) Ti 2-yr (min) Ti 10-yr (min) Ti 100-yr (min) Length, L (ft) Slope, S (%) Velocity, V (ft/s) Tt (min) Length, L (ft) Slope, S (%) Velocity, V (ft/s) Tt (min) 2-yr Landmark Residences on Mountain Avenue Rational Method Equation: Project: 1032 W. Mountain Calculations By: Date: From Section 3.2.1 of the CFCSDDC Rainfall Intensity: h1 H1 0.01 5 5 5 0.46 0.46 0.58 2.85 4.87 9.95 0.02 0.03 0.08 h2 H2 0.22 5 5 5 0.78 0.78 0.97 2.85 4.87 9.95 0.48 0.82 2.09 h3 H3 0.24 5 5 5 0.80 0.80 1.00 2.85 4.87 9.95 0.54 0.93 2.36 h4 H4 0.23 5 5 5 0.88 0.88 1.00 2.85 4.87 9.95 0.57 0.97 2.26 C2 C10 C100 HISTORIC RUNOFF COMPUTATIONS Intensity, i2 (in/hr) Intensity, i10 (in/hr) Intensity, i100 (in/hr) C. Snowdon December 17, 2014 Rainfall Intensity taken from the City of Fort Collins Storm Drainage Design Criteria (CFCSDDC), Figure 3.1 Design Point Basin(s) Area, A (acres) 2-yr Tc (min) 10-yr Tc (min) 100-yr Tc (min) Flow, Q2 (cfs) Flow, Q10 (cfs) Flow, Q100 (cfs) Q = C f ( C )( i )( A ) Page 3 of 7 D:\Projects\1022-001\Drainage\Hydrology\1022-001_Rational-Calcs.xlsx\Hist-Direct-Runoff Landmark Residences on Mountain Avenue CHARACTER OF SURFACE: Runoff Coefficient Percentage Impervious Project: 1032 W. Mountain Streets, Parking Lots, Roofs, Alleys, and Drives: Calculations By: Asphalt ……....……………...……….....…...……………….………………………………….. 0.95 100% Date: Concrete …….......……………….….……….………………..….………………………………… 0.95 90% Gravel ……….…………………….….…………………………..……………………………….. 0.50 40% Roofs …….…….………………..……………….…………………………………………….. 0.95 90% Pavers…………………………...………………..…………………………………………….. 0.40 22% Lawns and Landscaping Sandy Soil ……..……………..……………….…………………………………………….. 0.15 0% Clayey Soil ….….………….…….…………..………………………………………………. 0.25 0% 2-year Cf = 1.00 100-year Cf = 1.25 Basin ID Basin Area (s.f.) Basin Area (ac) Area of Asphalt (sq ft) Area of Asphalt (ac) Area of Concrete (sq ft) Area of Concrete (ac) Area of Roofs (sq ft) Area of Roofs (ac) Area of Gravel (sq ft) Area of Gravel (ac) Area of Pavers (sq ft) Area of Pavers (ac) Area of Lawns and Landscaping (ac) 2-year Composite Runoff Coefficient 10-year Composite Landmark Residences on Mountain Avenue Overland Flow, Time of Concentration: Project: 1032 W. Mountain Calculations By: Date: Gutter/Swale Flow, Time of Concentration: Tt = L / 60V Tc = Ti + Tt (Equation RO-2) Velocity (Gutter Flow), V = 20·S ½ Velocity (Swale Flow), V = 15·S ½ NOTE: C-value for overland flows over grassy surfaces; C = 0.25 Is Length >500' ? C*Cf (2-yr Cf=1.00) C*Cf (10-yr Cf=1.00) C*Cf (100-yr Cf=1.25) Length, L (ft) Up Stream Elevation Down Stream Elevation Slope, S (%) Ti 2-yr (min) Ti 10-yr (min) Ti 100-yr (min) Length, L (ft) Up Stream Elevation Down Stream Elevation Slope, S (%) Velocity, Landmark Residences on Mountain Avenue Rational Method Equation: Project: 1032 W. Mountain Calculations By: Date: From Section 3.2.1 of the CFCSDDC Rainfall Intensity: a1 A1 0.08 5 5 5 0.80 0.80 1.00 2.85 4.87 9.95 0.18 0.30 0.77 b1 B1 0.06 5 5 5 0.87 0.87 1.00 2.85 4.87 9.95 0.14 0.24 0.56 c1 C1 0.34 5 5 5 0.77 0.77 0.96 2.85 4.87 9.95 0.73 1.26 3.21 d1 D1 0.15 5 5 5 0.68 0.68 0.85 2.85 4.87 9.95 0.29 0.50 1.26 os1 OS1 0.02 5 5 5 0.92 0.92 1.00 2.85 4.87 9.95 0.05 0.08 0.18 os2 OS2 0.01 5 5 5 0.15 0.15 0.19 2.85 4.87 9.95 0.01 0.01 0.02 os3 OS3 0.03 5 5 5 0.35 0.35 0.44 2.85 4.87 9.95 0.04 0.06 0.15 os4 OS4 0.01 5 5 6 0.95 0.95 1.00 2.85 4.87 9.31 0.04 0.07 0.13 Area, A (acres) Intensity, i2 (in/hr) 100-yr Tc (min) DEVELOPED RUNOFF COMPUTATIONS C100 Design Point Flow, Q100 (cfs) Flow, Q2 (cfs) 10-yr Tc (min) 2-yr Tc (min) C2 Flow, Q10 (cfs) Intensity, i100 (in/hr) Basin(s) C. Snowdon December 17, 2014 Intensity, i10 (in/hr) Rainfall Intensity taken from the City of Fort Collins Storm Drainage Design Criteria (CFCSDDC), Figure 3.1 C10 Q = C f ( C )( i )( A ) Page 6 of 7 D:\Projects\1022-001\Drainage\Hydrology\1022-001_Rational-Calcs.xlsx\Direct-Runoff Landmark Residences on Mountain Avenue DESIGN POINT BASIN ID TOTAL AREA (acres) C10 C100 10-yr Tc (min) 100-yr Tc (min) Q2 (cfs) Q100 (cfs) a1 A1 0.077 0.80 1.00 5.0 5.0 0.18 0.77 b1 B1 0.056 0.87 1.00 5.0 5.0 0.14 0.56 c1 C1 0.335 0.77 0.96 5.0 5.0 0.73 3.21 d1 D1 0.149 0.68 0.85 5.0 5.0 0.29 1.26 os1 OS1 0.018 0.92 1.00 5.0 5.0 0.05 0.18 os2 OS2 0.012 0.15 0.19 5.0 5.0 0.01 0.02 os3 OS3 0.035 0.35 0.44 5.0 5.0 0.04 0.15 os4 OS4 0.014 0.95 1.00 5.0 6.0 0.04 0.13 DESIGN POINT BASIN ID TOTAL AREA (acres) C10 C100 10-yr Tc (min) 100-yr Tc (min) Q2 (cfs) Q100 (cfs) h1 H1 0.01 0.46 0.58 5.0 5.0 0.02 0.08 h2 H2 0.22 0.78 0.97 5.0 5.0 0.48 2.09 h3 H3 0.24 0.80 1.00 5.0 5.0 0.54 2.36 h4 H4 0.23 0.88 1.00 5.0 5.0 0.57 2.26 Page 7 of 7 D:\Projects\1022-001\Drainage\Hydrology\1022-001_Rational-Calcs.xlsx\SUMMARY-TABLE APPENDIX B HYDRAULIC COMPUTATIONS B.1 – Storm Sewers (Future Use) B.2 – Inlets (Future Use) B.3 – Detention Facilities APPENDIX B.1 STORM SEWERS (RESERVED FOR FUTURE USE) APPENDIX B.2 INLETS (RESERVED FOR FUTURE USE) 3130 Verona Avenue • Buford, GA 30518 (866) 888-8479 / (770) 932-2443 • Fax: (770) 932-2490 © Nyloplast Inlet Capacity Charts June 2012 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.50 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10 Capacity (cfs) Head (ft) Nyloplast 12" Standard Grate Inlet Capacity Chart APPENDIX C FLOODPLAIN REGULATION QUICK GUIDE Quick Guide City of Fort Collins Floodplain Regulations Quick Guide 03/09 2 Table of Odds for Different Events Floodplain Facts • Property in the 100-year floodplain has a 1 percent chance in any given year of being flooded. • Over a 30-year period, there is a 26 percent chance that a property in the 100-year floodplain will be flooded. For comparison, there is only a 5 percent chance that the building will catch fire during that same 30-year period. • Some properties have an even higher risk of flooding because they are in areas where smaller, more frequent floods cause damage. Purpose of Floodplain Regulations Event Odds 1 in 100 1 in 124 1 in 500 1 in 4,000 1 in 600,000 1 in 120,526,770 3 Types of Floodplains • In Fort Collins, floodplains are designated by the City as well as by the Federal Emergency Management Agency (FEMA). • The FEMA-basin floodplains cover only the major drainages. Changes in these floodplains must be approved by FEMA (p. 5). • The City-basin floodplains further identify the flood hazard. Some of the flooding in City-basin floodplains is from irrigation ditch spills or undersized storm sewers that result in overland flooding. Changes in these floodplains can be approved by the City (p. 5). • For floodplain regulation purposes, a floodplain property is either in a FEMA-basin floodplain, a City-basin floodplain or the Poudre River floodplain. Floodplain Name Poudre River Spring Creek Dry Creek Cooper Slough Boxelder Creek Fossil Creek Old Town Canal Importation McClellands Creek Mail Creek Foothills Channel West Vine FEMA-Basin X X X X Poudre River City-Basin X X X X X X X X Floodplain Designations 4 Floodway 5 6 Summary of Floodway Development Regulations Residential Development • New residential development is not allowed. • Fill is not allowed unless the applicant can show no-rise (Floodway Modifications, p. 5). • Residential additions are not allowed. • Remodels are allowed subject to the substantial improvement requirements (p. 14-15). • Manufactured homes are allowed only in existing manufactured home parks. • Redevelopment (rebuild) of an existing structure is allowed (p. 14-15). Must meet the freeboard requirements for redevelopments (p. 10). • Detached garages and sheds are allowed if the applicant can show no-rise (p. 17 and Floodway Modifications, p. 5). Non-Residential Development • New non-residential development is allowed if the applicant can show no- rise (Floodway Modifications, p. 5). Must meet the freeboard requirements (p. 10-11). • Fill is not allowed unless the applicant can show no-rise (Floodway Modifications, p. 5). • Non-residential additions are allowed if the applicant can show no-rise (Floodway Modifications, p. 6). Must meet the freeboard requirements (p. 10-11). • Remodels are allowed subject to the substantial improvement requirements (p. 14-16). • Mobile buildings (modular offices) are allowed only in existing mobile building developments. • Redevelopment (rebuild) of an existing structure is allowed (p. 14-16). Must meet the freeboard requirements for redevelopments (p. 10-11). • Attached garages, detached garages and sheds are allowed if the applicant can show no-rise (p. 17 and Floodway Modifications, p. 5). Mixed-Use Development • New mixed-use development is not allowed. • Fill is not allowed unless the applicant can show no-rise (Floodway Modifications, p. 5). • Residential additions are not allowed to a mixed-use structure. Non-residential additions are allowed to a mixed-use structure if the applicant can show no-rise (Floodway Modifications, p. 5). Must meet the freeboard requirements (p. 10-11). 7 • Critical facilities are not allowed (p. 18). • New basements are not allowed below the freeboard level (p. 10). An existing basement in a redeveloped or substantially improved structure is not allowed to remain (p. 10 and 14-15). • Critical facilities are not allowed (p. 18). • New basements are not allowed below the freeboard level (p. 10-11). An exist- ing basement in a redeveloped or sub-stantially improved structure can remain if floodproofed (p. 10-11 and 14-16). • New outside storage of equipment or materials is not allowed unless the applicant can show no rise (Floodway Modifications, p. 5). • Critical facilities are not allowed (p. 18). • New basements are not allowed below the freeboard level (p. 10-11). An existing basement in a redeveloped or substantially improved structure is not allowed to remain if it is in residential use (p. 10 and 14-15). An existing basement in a redeveloped or substantially improved structure is allowed to remain if it is in nonresidential use and floodproofed (p. 10-11 and 14-16). • New outside storage of equipment or materials is not allowed unless the applicant can show no rise (Floodway Modifications, p. 5) Summary of Floodway Development Regulations (continued) Residential Development Non-Residential Development Mixed-Use Development 8 Summary of Floodplain Fringe Development Regulations Residential Development • New residential development is allowed. Must meet the freeboard requirements (p. 10). • Fill is allowed. • Residential additions are allowed. Must meet the freeboard requirements (p. 10). • Remodels are allowed subject to the substantial improvement requirements (p. 14-15). • Manufactured homes are allowed only to replace an existing manufactured home or fill a vacant lot in an existing manufactured home park. • Redevelopment (rebuild) of an existing structure is allowed (p. 14-15). Must meet the freeboard requirements for redevelopments (p. 10). • Attached garages, detached garages and sheds are allowed (p. 17). • Critical facilities are not allowed (p. 18). Non-Residential Development • New non-residential development is allowed. Must meet the freeboard requirements (p. 10-11). • Fill is allowed. • Non-residential additions are allowed. Must meet the freeboard requirements (p. 10-11). • Remodels are allowed subject to the substantial improvement requirements (p. 14-16). • Mobile buidlings (modular offices) are allowed only to replace an existing mobile building or fill a vacant lot in an existing mobile building development. • Redevelopment (rebuild) of an existing structure is allowed (p. 14-16). Must meet the freeboard requirements for redevelopments (p. 10-11). • Attached garages, detached garages and sheds are allowed (p. 17). • Critical facilities are not allowed (p. 18). Mixed-Use Development • New mixed-use development is allowed. Must meet the freeboard requirements (p. 10-11). • Fill is allowed. • Mixed-use additions are allowed. Must meet the freeboard requirements (p. 10-11). • Remodels are allowed subject to the substantial improvement requirements (p. 14-16). • Redevelopment (rebuild) of an existing structure is allowed (p. 14-16). Must meet the freeboard requirements for redevelopments (p. 10-11). 9 Mixed-Use Development • New basements are not allowed below the freeboard level for residential portions of mixed-use structures (p. 10). An existing basement in a redeveloped or substantially improved structure is not allowed to remain if it is in residential use (p. 10 and 14-15). New basements are allowed for non-residential portions of mixed- use structures. Must meet freeboard requirements and be floodproofed (p. 10-11). An existing basement in a redeveloped or substantially improved structure is allowed to remain if it is in non-residential use and floodproofed (p. 10-11 and 14-16). Non-Residential Development • New basements are allowed. Must meet freeboard requirements and be floodproofed (p. 10-11). An existing basement below the freeboard level in a redeveloped or substantially improved structure can remain if floodproofed (p. 10-11 and 14-16). Residential Development • New basements are not allowed below the freeboard level (p. 10). An existing basement in a redeveloped or substantially improved structure is not allowed to remain (p. 10 and 14-15). Summary of Floodplain Fringe Development Regulations (continued) 10 Freeboard Example of new development residential elevation (See p. 12-13 for detailed foundation designs) Slab on grade foundation Crawl space foundation 11 Freeboard continued Example of residential addition 12 Determination of Lowest Floor Based on Type of Foundation Lowest floor Freeboard elevation Floor slab on grade Freeboard Vents Enclosure Lowest floor elevation Unfinished area no HVAC Vents Lowest floor Freeboard elevation Basement Basement slab Freeboard Can have HVAC in enclosed area Lowest floor elevation Enclosure 13 Determination of Lowest Floor Based on Type of Foundation continued Pump f Vent b Maximum 2 feet Freeboard a Velocity < 5 ft. per sec. c No more than 4 feet to top of foundation wall Crawl space e Duct Work d 14 Vertical (Pop-top) addition All remodel work, including vertical addition, counts toward substantial improvement Vertical (Pop-top) addition Remodel work on these floors counts toward substantial improvement Remodel work, including vertical addition, does not count toward substantial improvement 15 Substantial Improvement and Redevelopment elevated 6" or 18" Example of residential substantial improvement or redevelopment 16 Store Store Store Store Basement Store Store Basement Apartments Apartments Substantial Improvement and Redevelopment continued Example of non-residential and mixed-use substantial improvements or redevelopments 17 Use flood resistant materials to 6" above flood level Example of attached structure Example of detached structure Use flood resistant materials to 18" above flood level Garages, Sheds and Accessory Structures 18 Examples of critical facilities 19 20 21 22 Required Documentation and Submittals (Note: Some items may require a registered professional engineer.) 23 Example of Flood Risk Map APPENDIX D WATER QUALITY DESIGN COMPUTATIONS Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Type of Permeable Pavement Section A) What type of section of permeable pavement is used? (Based on the land use and activities, proximity to adjacent structures and soil characteristics.) B) What type of wearing course? 2. Required Storage Volume A) Effective Imperviousness of Area Tributary to Permeable Pavement, Ia I a = 100.0 % B) Tributary Area's Imperviousness Ratio (I = Ia / 100) i = 1.000 C) Tributary Watershed Area ATotal = 2,454 sq ft (including area of permeable pavement system) D) Area of Permeable Pavement System APPS = 1,126 sq ft (Minimum recommended permeable pavement area = 818 sq ft) E) Impervious Tributary Ratio RT = 1.2 (Contributing Imperviuos Area / Permeable Pavement Ratio) F) Water Quality Capture Volume (WQCV) Based on 12-hour Drain Time WQCV = 82 cu ft (WQCV = (0.8 * (0.91 * i 3 - 1.19 * i 2 + 0.78 * i) / 12) * Area) G) Is flood control volume being added? H) Total Volume Needed VTotal = cu ft 3. Depth of Reservoir A) Minimum Depth of Reservoir Dmin = 12.0 inches (Minimum recommended depth is 6 inches) B) Is the slope of the reservoir/subgrade interface equal to 0%? C) Porosity (Porous Gravel Pavement < 0.3, Others < 0.40) P = 0.40 D) Slope of the Base Course/Subgrade Interface S = 0.005 ft / ft E) Length Between Lateral Flow Barriers (max = 72.65 ft.) L = 70.0 ft F) Volume Provided Based on Depth of Base Course V = 334 cu ft Flat or Stepped: V = P * ((Dmin-1)/12) * Area Sloped: V = P * [(Dmin - (D min - 6*SL-1)) / 12] * Area Volume assumes uniform slope & lateral flow barrier spacing. Calculate the volume of each cell individually when this varies. 4. Lateral Flow Barriers A) Type of Lateral Flow Barriers B) Number of Permeable Pavement Cells Cells = 2 5. Perimeter Barrier A) Is a perimeter barrier provided on all sides of the pavement system? (Recommeded for PICP, concrete grid pavement, or for any no-infiltration section.) Landmark Residences on Mountain Avenue Mountain and Shields Design Procedure Form: Permeable Pavement Systems (PPS) Cody Snowdon Northern Engineering December 17, 2014 Sheet 2 of 2 Designer: Company: Date: Project: Location: 6. Filter Material and Underdrain System A) Is the underdrain placed below a 6-inch thick layer of CDOT Class C filter material? B) Diameter of Slotted Pipe (slot dimensions per Table PPs-2) C) Distance from the Lowest Elevation of the Storage Volume y = 0.3 ft (i.e. the bottom of the base course to the center of the orifice) 7. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is there a minimum 30 mil thick impermeable PVC geomembrane liner on the bottom and sides of the basin, extending up to the top of the base course? B) CDOT Class B Separator Fabric 8. Outlet (Assumes each cell has similar area, subgrade slope, and length between lateral barriers (unless subgrade is flat). Calculate cells individually where this varies.) A) Depth of WQCV in the Reservoir DWQCV = 4.28 inches (Elevation of the Flood Control Outlet) B) Diameter of Orifice for 12-hour Drain Time DOrifice = 0.31 inches MINIMUM ORIFICE SIZE IS 3/8-INCHES (Use a minimum orifice diameter of 3/8-inches) Notes: Landmark Residences on Mountain Avenue Design Procedure Form: Permeable Pavement Systems (PPS) Cody Snowdon Northern Engineering December 17, 2014 Mountain and Shields Choose One YES NO Choose One 4-inch 6-inch Choose One Choose One YES NO Placed above the liner Placed above and below the liner N/A UD-BMP_v3.02.xls, PPS 12/17/2014, 3:40 PM APPENDIX E EROSION CONTROL REPORT Landmark Residences on Mountain Avenue Preliminary Erosion Control Report A comprehensive Erosion and Sediment Control Plan (along with associated details) will be included with the final construction drawings. It should be noted, however, that any such Erosion and Sediment Control Plan serves only as a general guide to the Contractor. Staging and/or phasing of the BMPs depicted, and additional or different BMPs from those included may be necessary during construction, or as required by the authorities having jurisdiction. It shall be the responsibility of the Contractor to ensure erosion control measures are properly maintained and followed. The Erosion and Sediment Control Plan is intended to be a living document, constantly adapting to site conditions and needs. The Contractor shall update the location of BMPs as they are installed, removed or modified in conjunction with construction activities. It is imperative to appropriately reflect the current site conditions at all times. The Erosion and Sediment Control Plan shall address both temporary measures to be implemented during construction, as well as permanent erosion control protection. Best Management Practices from the Volume 3, Chapter 7 – Construction BMPs will be utilized. Measures may include, but are not limited to, silt fencing along the disturbed perimeter, gutter protection in the adjacent roadways and inlet protection at proposed storm inlets. Vehicle tracking control pads, spill containment and clean-up procedures, designated concrete washout areas, dumpsters, and job site restrooms shall also be provided by the Contractor. Grading and Erosion Control Notes can be found on Sheet CS2 of the Utility Plans. The Utility Plans at final design will also contain a full-size Erosion Control Plan as well as a separate sheet dedicated to Erosion Control Details. In addition to this report and the referenced plan sheets, the Contractor shall be aware of, and adhere to, the applicable requirements outlined in any existing Development Agreement(s) of record, as well as the Development Agreement, to be recorded prior to issuance of the Development Construction Permit. Also, the Site Contractor for this project will be required to secure a Stormwater Construction General Permit from the Colorado Department of Public Health and Environment (CDPHE), Water Quality Control Division – Stormwater Program, before commencing any earth disturbing activities. Prior to securing said permit, the Site Contractor shall develop a comprehensive StormWater Management Plan (SWMP) pursuant to CDPHE requirements and guidelines. The SWMP will further describe and document the ongoing activities, inspections, and maintenance of construction BMPs. APPENDIX F NRCS SOILS REPORT United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Larimer County Area, Colorado Landmark Residences on Mountain Avenue Natural Resources Conservation Service December 17, 2014 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/portal/ nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (http:// offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means 2 for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................7 Soil Map................................................................................................................8 Legend..................................................................................................................9 Map Unit Legend................................................................................................10 Map Unit Descriptions........................................................................................10 Larimer County Area, Colorado......................................................................12 35—Fort Collins loam, 0 to 3 percent slopes..............................................12 Soil Information for All Uses...............................................................................13 Soil Properties and Qualities..............................................................................13 Soil Qualities and Features.............................................................................13 Hydrologic Soil Group (Landmark Residences on Mountain Avenue)........13 References............................................................................................................18 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil scientists classified and named the soils in the survey area, they compared the 5 individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil- landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 6 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 7 8 Custom Soil Resource Report Soil Map 4492930 4492940 4492950 4492960 4492970 4492980 4492990 4493000 4493010 4493020 4492930 4492940 4492950 4492960 4492970 4492980 4492990 4493000 4493010 4493020 491890 491900 491910 491920 491930 491940 491950 491890 491900 491910 491920 491930 491940 491950 40° 35' 16'' N 105° 5' 45'' W 40° 35' 16'' N 105° 5' 42'' W 40° 35' 13'' N 105° 5' 45'' W 40° 35' 13'' N 105° 5' 42'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 20 40 80 120 Feet 0 5 10 20 30 Meters Map Scale: 1:448 if printed on A portrait (8.5" x 11") sheet. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of Map Unit Legend Larimer County Area, Colorado (CO644) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 35 Fort Collins loam, 0 to 3 percent slopes 0.9 100.0% Totals for Area of Interest 0.9 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. Custom Soil Resource Report 10 An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha- Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 11 Larimer County Area, Colorado 35—Fort Collins loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2tlnc Elevation: 4,020 to 6,730 feet Mean annual precipitation: 14 to 16 inches Mean annual air temperature: 46 to 48 degrees F Frost-free period: 143 to 154 days Farmland classification: Prime farmland if irrigated Map Unit Composition Fort collins and similar soils: 85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Fort Collins Setting Landform: Interfluves Down-slope shape: Linear Across-slope shape: Linear Parent material: Pleistocene or older alluvium derived from igneous, metamorphic and sedimentary rock and/or eolian deposits Typical profile Ap - 0 to 4 inches: loam Bt1 - 4 to 9 inches: clay loam Bt2 - 9 to 16 inches: clay loam Bk1 - 16 to 29 inches: loam Bk2 - 29 to 80 inches: loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.20 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 12 percent Salinity, maximum in profile: Nonsaline (0.1 to 1.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 0.5 Available water storage in profile: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 4c Hydrologic Soil Group: C Ecological site: Loamy plains (R067BY002CO) Custom Soil Resource Report 12 Soil Information for All Uses Soil Properties and Qualities The Soil Properties and Qualities section includes various soil properties and qualities displayed as thematic maps with a summary table for the soil map units in the selected area of interest. A single value or rating for each map unit is generated by aggregating the interpretive ratings of individual map unit components. This aggregation process is defined for each property or quality. Soil Qualities and Features Soil qualities are behavior and performance attributes that are not directly measured, but are inferred from observations of dynamic conditions and from soil properties. Example soil qualities include natural drainage, and frost action. Soil features are attributes that are not directly part of the soil. Example soil features include slope and depth to restrictive layer. These features can greatly impact the use and management of the soil. Hydrologic Soil Group (Landmark Residences on Mountain Avenue) Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long- duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. 13 Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Custom Soil Resource Report 14 15 Custom Soil Resource Report Map—Hydrologic Soil Group (Landmark Residences on Mountain Avenue) 4492930 4492940 4492950 4492960 4492970 4492980 4492990 4493000 4493010 4493020 4492930 4492940 4492950 4492960 4492970 4492980 4492990 4493000 4493010 4493020 491890 491900 491910 491920 491930 491940 491950 491890 491900 491910 491920 491930 491940 491950 40° 35' 16'' N 105° 5' 45'' W 40° 35' 16'' N 105° 5' 42'' W 40° 35' 13'' N 105° 5' 45'' W 40° 35' 13'' N 105° 5' 42'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 20 40 80 120 Feet 0 5 10 20 30 Meters Map Scale: 1:448 if printed on A portrait (8.5" x 11") sheet. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Table—Hydrologic Soil Group (Landmark Residences on Mountain Avenue) Hydrologic Soil Group— Summary by Map Unit — Larimer County Area, Colorado (CO644) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 35 Fort Collins loam, 0 to 3 percent slopes C 0.9 100.0% Totals for Area of Interest 0.9 100.0% Rating Options—Hydrologic Soil Group (Landmark Residences on Mountain Avenue) Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Custom Soil Resource Report 17 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http://www.nrcs.usda.gov/wps/ portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 18 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 19 MAP POCKET C5.00 DRINAGE EXHIBIT WV WV WV H Y D WV VAULT ELEC CONTROL IRR WV H2O IRR VAULT ELEC W VAULT ELEC W ELEC VAULT ELEC T GAS GAS X X X X X X X X X X X X X X X X X X X X X X E T S TRAFFIC VAULT TRAFFIC VAULT TRAFFIC VAULT X EXISTING HIGH POINT EXISTING CURB INLET H2 0.97 0.217 H1 0.58 0.014 H3 1.00 0.239 H4 1.00 0.227 h1 h2 CONTROL IRR GAS X X X X X X X X X X X X X X X X X E VAULT CABLE X X X X X X X UD UD UD UD UD UD E EV E E CO CO CO CO CO E E E E E E G G G G G G E G E G G G G G E E E E E E E G G G G G G G G G G UP UP UP DENEK JASON T/ CHISTINE D 9852 CLAIRTON PL LITTLETON, CO 80126 W. MOUNTAIN AVE. (140' ROW) N. SHIELDS ST. (60' ROW) FRARE BARBARA L 1016 W. MOUNTAIN AVE. FORT COLLINS, CO 80521 CALLAWAY JEFFERY RYAN EDWARDS-CALAWAY LILY NOWELL 112 N. SSHIELDS ST. FORT COLLINS, CO 80521 BEAVERS MARKET INC NO.3 1100 W. MOUNTAIN AVE. FORT COLLINS, CO 80521 CHILDRENS HOUSE MONTESSORI SCHOOL LLC 113 N. SHIELDS ST. FORT COLLINS, CO 80521 FFE=24.90 FFE=25.40 FFE=25.40 FFE=25.40 FFE=25.40 FFE=25.40 FFE=25.40 GARAGE FFE=23.77 PROPERTY BOUNDARY 6485 - 5021.47 NAVD 88 6703 - 5023.17 NAVD 88 PUBLIC ALLEY GARAGE FFE=23.76 GARAGE FFE=23.77 GARAGE FFE=23.28 GARAGE FFE=24.11 GARAGE FFE=24.10 GARAGE FFE=24.10 GARAGE FFE=24.11 GARAGE FFE=24.09 No. Revisions: By: Date: REVIEWED BY: R. Curtiss DESIGNED BY: DRAWN BY: SCALE: DATE: May 6, 2015 PROJECT: 1022-001 Sheet Of 18 Sheets LANDMARK RESIDENCES ON MOUNTAIN AVENUE DRAWING FILENAME: D:rojects\1022-001\Dwg\Drng\1022-001_Flood Exhibit.dwg LAYOUT NAME: F1 DATE: May 06, 2015 - 11:39am CAD OPERATOR: ben LIST OF XREFS: [1022-001_xTopo] [1022-001_xExst] [1022-001_xPgrad] [1022-001_xPutil] [1022-001_xSite] [NES-xborder] [1022-001_xFloodplain] These drawings are instruments of service provided by Northern Engineering Services, Inc. and are not to be used for any type of construction unless signed and sealed by a Professional Engineer in the employ of Northern Engineering Services, Inc. NOT FOR CONSTRUCTION REVIEW SET 301 North Howes Street, Suite 010 Fort Collins, Colorado 80521 E N G I N E E R I N G N O R T H E RN PHONE: 970.221.4158 FAX: 970.221.4159 www.northernengineering.com 05.06.15 C6.01 FLOODPLAIN EXHIBIT C. Snowdon A. Boese 1"=20' CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO Know what'sbelow. Call before you dig. R City Engineer Date Date Date Date Date Stormwater Utility Parks & Recreation Traffic Engineer Date APPROVED: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Water & Wastewater Utility City of Fort Collins, Colorado UTILITY PLAN APPROVAL Environmental Planner ( IN FEET ) 1 inch = ft. 20 0 20 Feet 20 40 60 NORTH EXISTING CITY FLOODWAY NOTES: 1.REFER TO THE PLAT FOR LOT AREAS, TRACT SIZES, EASEMENTS, LOT DIMENSIONS, UTILITY EASEMENTS, OTHER EASEMENTS, AND OTHER SURVEY INFORMATION. 2.ALL ELEVATIONS DEPICTED IN PLAN VIEW AND BENCHMARKS LISTED HEREON ARE PER THE CITY OF FORT COLLINS VERTICAL CONTROL DATUM (NAVD88) 3.A FLOODPLAIN USE PERMIT SHALL BE REQUIRED FOR EACH STRUCTURE AND EACH SITE CONSTRUCTION ELEMENT (DETENTION PONDS, BIKE PATHS, PARKING LOT, UTILITIES, ETC.) IN THE HIGH RISK FLOOD FRINGE AND FLOODWAY. 4.NO STORAGE OF MATERIALS OR EQUIPMENT SHALL BE ALLOWED IN THE FLOODWAY, WHETHER TEMPORARY (DURING CONSTRUCTION) OR PERMANENT. LANDSCAPING SHALL ALSO MEET THE REQUIREMENTS FOR NO RISE IN THE FLOODWAY. {5.REFER TO THE PRELIMINARY DRAINAGE REPORT FOR LANDMARK RESIDENCES ON MOUNTAIN AVENUE BY NORTHERN ENGINEERING, DATED MAY 6, 2015 FOR ADDITIONAL INFORMATION. 6.A NO RISE CERTIFICATION IS REQUIRED FOR ANY WORK WITHIN THE FLOODWAY SUCH AS UTILITIES, LANDSCAPING, CURB & GUTTER, ETC. 7.ALL HVAC EQUIPMENT IS TO BE LOCATED ON THE ROOFTOP OF THE STRUCTURE. 8.ALL STRUCTURES WITHIN THE FLOODWAY (PICNIC TABLES, BIKE RACKS, ETC.) SHALL BE ANCHORED. 9.DUMPSTER SHALL BE SECURED TO PREVENT OFFSITE FLOATATION DURING A 100-YEAR STORM. 10.NO CRITICAL FACILITIES OR USES MAY BE CREATED IN ANY FLOOD ZONE. 11.A FEMA ELEVATION CERTIFICATION SHALL BE PROVIDED AND APPROVED FOR EACH BUILDING PRIOR TO THE ISSUANCE OF A CERTIFICATION OF OCCUPANCY.} FIELD SURVEY BY: BENCHMARKS: Northern Engineering Service, Inc. Project No. 1022-001 Date: April 23, 2014 CROSS-SECTION (CSL) BASE FLOOD ELEVATION (BFE) ELEVATION NGVD 29 (UNADJUSTED) 5000 20554 LEGEND: 5013 PROPOSED CONTOUR 93 EXISTING CONTOUR EXISTING STORM SEWER LINE W/ MH ST D EXISTING ROW LINE EXISTING INLET GRATE LIMITS OF 100-YR FLOOD FRINGE / / / / / / / / / / / / / / / / / / / / / / / / / / / / PROPOSED UNDERDRAIN UD PROPOSED STORM DRAIN PROPOSED CURB & GUTTER EXISTING CURB & GUTTER FOR STORMWATER REVIEW ONLY NOT FOR CONSTRUCTION EXISTING HIGH RISK FLOODPLAIN {PROJECT DATUM: NAVD88 BENCHMARK #1: City of Fort Collins Benchmark 3-08 Southwest corner of Mulberry St. and Shields St. on a concrete traffic signal base Elevation = 5030.29 BENCHMARK #2: City of Fort Collins Benchmark 31-97 Southwest corner of Laporte Ave. and Sheilds St., on a concrete traffic signal base. Elevation = 5023.65} LOWEST FLOOR ELEVATION = C BASE FLOOD ELEVATION (BFE) = A MINIMUM HVAC EQUIPMENT ELEVATION BASE = FLOOD B ELEVATION (BFE) = A 18" MIN. 18" MIN. DETAIL NTS SLAB-ON-GRADE COMMERCIAL EL. DESIGNATION NAVD 88 A 5022.99 FT B 5037.00 FT (ROOF) C 5024.90 FT REGULATORY FLOOD PROTECTION ELEVATION 5024.49 FT RESIDENTIAL EL. DESIGNATION NAVD 88 A 5022.87 FT B 5043.54 FT (ATTIC) C 5025.40 FT REGULATORY FLOOD PROTECTION ELEVATION 5024.37 FT h3 h4 N. SHIELDS STREET W. MOUNTAIN AVE. ALLEY UP UP UP UD UD UD UD UD UD CO CO CO CO CO WV WV WV H Y D WV VAULT ELEC CONTROL IRR W VAULT ELEC GAS E T S TRAFFIC VAULT TRAFFIC VAULT TRAFFIC VAULT PROPOSED BUILDING MONITORING WELL W/ OPEN GRATE FOR MINOR STORM 6" PERFORATED UNDERDRAIN 6" PERFORATED UNDERDRAIN EXISTING HIGH POINT EXISTING CURB INLET MAJOR STORM TO OVERTOP DRIVE CUT N. SHIELDS STREET W. MOUNTAIN AVE. ALLEY acres OS2 0.15 0.012 0.19 acres OS1 0.92 0.018 1.00 acres A1 0.80 0.077 1.00 acres B1 0.87 0.056 1.00 acres C1 0.77 0.335 0.96 acres D1 0.68 0.149 0.85 acres OS3 0.35 0.035 0.44 acres OS4 0.95 0.014 1.00 os1 b1 a1 c1 d1 os3 os2 os4 MONITORING WELL W/ OPEN GRATE FOR MINOR STORM MAJOR STORM TO OVERTOP PIPE END w/ CONCRETE COLLAR FOR MINOR STORM MAJOR STORM TO OVERTOP DRAIN BASIN W/ OPEN GRATE FOR MINOR STORM DRAIN BASIN W/ OPEN GRATE FOR MINOR STORM No. Revisions: By: Date: REVIEWED BY: R. Curtiss DESIGNED BY: DRAWN BY: SCALE: DATE: May 6, 2015 PROJECT: 1022-001 Sheet Of 18 Sheets LANDMARK RESIDENCES ON MOUNTAIN AVENUE DRAWING FILENAME: D:rojects\1022-001\Dwg\Drng\1022-001_DRNG.dwg LAYOUT NAME: DR1 DATE: May 06, 2015 - 11:39am CAD OPERATOR: ben LIST OF XREFS: [1022-001_xPgrad] [1022-001_xPutil] [1022-001_xSite] [1022-001_xTopo] [1022-001_xExst] [NES-xborder] These drawings are instruments of service provided by Northern Engineering Services, Inc. and are not to be used for any type of construction unless signed and sealed by a Professional Engineer in the employ of Northern Engineering Services, Inc. NOT FOR CONSTRUCTION REVIEW SET 301 North Howes Street, Suite 010 Fort Collins, Colorado 80521 E N G I N E E R I N G N O R T H E RN PHONE: 970.221.4158 FAX: 970.221.4159 www.northernengineering.com 05.06.15 C6.00 DRAINAGE EXHIBIT C. Snowdon A. Boese 1"=20' FOR DRAINAGE REVIEW ONLY NOT FOR CONSTRUCTION LEGEND: NOTES: CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO Know what'sbelow. Call before you dig. R City Engineer Date Date Date Date Date Stormwater Utility Parks & Recreation Traffic Engineer Date APPROVED: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Water & Wastewater Utility City of Fort Collins, Colorado UTILITY PLAN APPROVAL Environmental Planner NORTH ( IN FEET ) 1 inch = ft. 20 0 20 Feet 20 40 60 5013 PROPOSED CONTOUR 93 PROPOSED SWALE EXISTING CONTOUR PROPOSED VERTICAL PROPOSED OVERLAND FLOW DIRECTION CURB & GUTTER EXISTING STORM SEWER LINE PROPERTY BOUNDARY EXISTING INLET GRATE PROPOSED UNDERDRAIN UD PROPOSED STORM DRAIN PROPOSED RIBBON CURB PROPOSED PERMEABLE PAVERS acres B 1.79 0.86 a BASIN ACREAGE DESIGN POINT BASIN DELINEATION MAJOR RUNOFF COEFFICIENT PROPOSED BASIN LINES HISTORIC DRAINAGE EXHIBIT PROPOSED DRAINAGE EXHIBIT Survey Area Data: Version 9, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Apr 22, 2011—Nov 18, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 16 the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 9, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Apr 22, 2011—Nov 18, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 9 Choose One No Infiltration Partial Infiltration Section Full Infiltration Section Choose One YES NO Choose One YES- Flat or Stepped Installation NO- Sloped Installation Choose One Concrete Walls PVC geomembrane installed normal to flow N/A- Flat installation Other (Describe): Choose One YES NO Choose One PICP Concrete Grid Pavement Pervious Concrete Porous Gravel UD-BMP_v3.02.xls, PPS 12/17/2014, 3:40 PM • Attached garages, detached garages and sheds are allowed (p. 17). • Critical facilities are not allowed (p. 18). • Remodels are allowed subject to the substantial improvement requirements (p. 14-16). • Redevelopment (rebuild) of an existing structure is allowed (p. 14-16). Must meet the freeboard requirements for redevelopments (p. 10-11). • Detached garages and sheds are allowed if the applicant can show no-rise (p. 17 and Floodway Modifications, p. 5). V (ft/s) Tt (min) Length, L (ft) Up Stream Elevation Down Stream Elevation Slope, S (%) Velocity, V (ft/s) Tt (min) 2-yr Tc (min) 10-yr Tc (min) 100-yr Tc (min) a1 A1 No 0.80 0.80 1.00 13 23.13 22.73 3.12% 1.4 1.4 0.5 104 22.73 21.84 0.86% 1.85 0.9 10 21.84 21.34 5.00% 3.35 0.0 5 5 5 b1 B1 No 0.87 0.87 1.00 27 23.81 22.96 3.15% 1.5 1.5 0.7 #DIV/0! N/A N/A N/A N/A N/A 5 5 5 c1 C1 No 0.77 0.77 0.96 22 25.35 24.36 4.50% 1.8 1.8 0.7 37 23.23 22.96 0.73% 1.71 0.4 71 24.36 23.24 1.58% 1.88 0.6 5 5 5 d1 D1 No 0.68 0.68 0.85 #DIV/0! N/A N/A N/A #DIV/0! N/A N/A N/A N/A N/A 5 5 5 os1 OS1 No 0.92 0.92 1.00 #DIV/0! N/A N/A N/A #DIV/0! N/A N/A N/A N/A N/A 5 5 5 os2 OS2 No 0.15 0.15 0.19 #DIV/0! N/A N/A N/A #DIV/0! N/A N/A N/A N/A N/A 5 5 5 os3 OS3 No 0.35 0.35 0.44 #DIV/0! N/A N/A N/A #DIV/0! N/A N/A N/A N/A N/A 5 5 5 os4 OS4 No 0.95 0.95 1.00 #DIV/0! N/A N/A N/A #DIV/0! N/A N/A N/A N/A N/A 5 5 6 DEVELOPED TIME OF CONCENTRATION COMPUTATIONS Gutter Flow Swale Flow Design Point Basin Overland Flow C. Snowdon December 17, 2014 Time of Concentration (Equation RO-4) ( ) 3 1 1 . 87 1 . 1 * S Ti C Cf L - = Page 5 of 7 D:\Projects\1022-001\Drainage\Hydrology\1022-001_Rational-Calcs.xlsx\Tc-10-yr_&_100-yr Runoff Coefficient 100-year Composite Runoff Coefficient Composite % Imperv. A1 3374 0.077 0.000 0.000 2294.000 0.053 453.000 0.010 0.000 0.000 0.000 0.000 0.014 0.80 0.80 1.00 73% B1 2450 0.056 0.000 0.000 1117.000 0.026 975.000 0.022 0.000 0.000 340.000 0.008 0.000 0.87 0.87 1.00 77% C1 14598 0.335 0.000 0.000 6191.000 0.142 4802.000 0.110 0.000 0.000 993.000 0.023 0.060 0.77 0.77 0.96 68% D1 6508 0.149 0.000 0.000 908.000 0.021 3408.000 0.078 0.000 0.000 0.000 0.000 0.050 0.68 0.68 0.85 60% OS1 775 0.018 0.000 0.000 746.000 0.017 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.92 0.92 1.00 87% OS2 523 0.012 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.012 0.15 0.15 0.19 0% OS3 1510 0.035 0.000 0.000 386.000 0.009 0.000 0.000 0.000 0.000 0.000 0.000 0.026 0.35 0.35 0.44 23% OS4 624 0.014 0.000 0.000 624.000 0.014 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.95 0.95 1.00 90% TOTAL 30362 0.697 0.000 0.000 12266.000 0.282 9638.000 0.221 0.000 0.000 1333.000 0.031 0.194 0.74 0.74 0.93 65% DEVELOPED COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS Runoff Coefficients are taken from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards, Table 3-3. % Impervious taken from UDFCD USDCM, Volume I. 10-year Cf = 1.00 December 17, 2014 **Soil Classification of site is Sandy Loam** C. Snowdon Page 4 of 7 D:\Projects\1022-001\Drainage\Hydrology\1022-001_Rational-Calcs.xlsx\C-Values Tc (min) 10-yr Tc (min) 100-yr Tc (min) h1 H1 No 0.46 0.46 0.58 31 1.00% 6.6 6.6 5.4 N/A N/A N/A N/A N/A N/A 7 7 5 h2 H2 No 0.78 0.78 0.97 110 0.50% 8.0 8.0 3.2 N/A N/A N/A N/A N/A N/A 8 8 5 h3 H3 No 0.80 0.80 1.00 100 0.70% 6.4 6.4 2.2 N/A N/A N/A N/A N/A N/A 6 6 5 h4 H4 No 0.88 0.88 1.00 79 1.00% 3.7 3.7 1.7 N/A N/A N/A N/A N/A N/A 5 5 5 HISTORIC TIME OF CONCENTRATION COMPUTATIONS C. Snowdon December 17, 2014 Design Point Basin Overland Flow Gutter Flow Swale Flow Time of Concentration (Equation RO-4) ( ) 3 1 1 . 87 1 . 1 * S Ti C Cf L - = Page 2 of 7 D:\Projects\1022-001\Drainage\Hydrology\1022-001_Rational-Calcs.xlsx\Hist-Tc-10-yr_&_100-yr **Soil Classification of site is Fort Collnis Loam** Runoff Coefficients are taken from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards, Table 3-3. % Impervious taken from UDFCD USDCM, Volume I. Page 1 of 7 D:\Projects\1022-001\Drainage\Hydrology\1022-001_Rational-Calcs.xlsx\Hist-C-Values