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HomeMy WebLinkAboutCSU HEALTH CENTER / GF WAIRDS REPLAT & UTILITY PLAN - PDP/FDP - FDP150039 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTDRAINAGE REPORT FOR CSU HEALTH AND MEDICAL CENTER AT 151 W. LAKE STREET FORT COLLINS, CO 80524 PREPARED FOR COLORADO STATE UNIVERSITY Fort Collins, CO 80523 NOVEMBER 11, 2015 Colorado State University Health and Medical Center Preliminary Drainage Report Page 1 of 13 TABLE OF CONTENTS SITE LOCATION AND DESCRIPTION ......................................................................................... 4 DRAINAGE BASINS AND HISTORIC RUNOFF ............................................................................. 5 HISTORIC DRAINAGE ......................................................................................................... 5 DRAINAGE DESIGN CRITERIA ................................................................................................ 7 HYDROLOGIC METHOD AND DESIGN STORM FREQUENCIES ................................................... 7 HYDRAULIC CRITERIA ........................................................................................................ 7 VARIANCES FROM THE CRITERIA ............................................................................................ 7 DRAINAGE FACILITY DESIGN ................................................................................................. 7 GENERAL CONCEPT ......................................................................................................... 7 PROPOSED DEVELOPED SUBBASINS .................................................................................... 8 PROPOSED DETENTION POND ......................................................................................... 10 HISTORIC/DEVELOPED BASIN COMPARISON ..................................................................... 11 STORM WATER MODELING ................................................................................................. 11 STORMWATER POLLUTION PREVENTION/EROSION CONTROL .................................................. 12 TEMPORARY EROSION CONTROL ..................................................................................... 12 PERMANENT EROSION CONTROL ..................................................................................... 12 CONCLUSIONS .................................................................................................................. 12 REFERENCES ...................................................................................................................... 12 LIST OF TABLES TABLE 1. HISTORIC SWMM BASIN PROPERTIES AND FLOWS ......................................................... 5 TABLE 2.DEVELOPED SWMM SUBBASIN PROPERTIES, FLOWS, AND RUNOFF COEFFICIENTS ........... 10 LIST OF FIGURES FIGURE 1. HISTORIC DRAINAGE BASINS (AYRES ASSOCIATES SWMM MODEL) ............................. 6 FIGURE 2. DEVELOPED DRAINAGE SUBBASINS (SWMM MODEL) ................................................. 8 Colorado State University Health and Medical Center Preliminary Drainage Report Page 2 of 13 APPENDICES Appendix A – Referenced Information 1. Urban Storm Drainage Criteria Manual Table RO-3 2. CSU Medical Center Project Drainage Memo from Ayres Associates 3. SPAR Comments and Meeting Minutes 4. Geotechnical Results and Soil Boring Logs 5. FEMA FIRM Map Appendix B – Hydraulic/Hydrologic Computations 1. SWMM Input Table (Historic – Ayres Associates Model) 2. SWMM Results (Historic – Ayres Associates Model) 3. SWMM Input Table (Developed) 4. SWMM Results (Developed) 5. Inlet Sizing Calculations Appendix C – Figure 1. Developed Drainage Map Colorado State University Health and Medical Center Preliminary Drainage Report Page 3 of 13 ENGINEER’S STATEMENT: “I hereby certify that this report (plan) for the Final Drainage Design CSU Health and Medical Center was prepared by me (or under my direct supervision) in accordance with the provisions of the City of Fort Collins Standards for the Responsible Parties thereof. I understand that the City of Fort Collins does not and shall not assume liability for drainage facilities designed by others.” ___ ________ _ Kevin A. Tone, P.E. Registered Professional Engineer State of Colorado No. 28699 Colorado State University Health and Medical Center Preliminary Drainage Report Page 4 of 13 SITE LOCATION AND DESCRIPTION The Colorado State University Health and Medical Center (site) is located in Section 14, Township 7 North, Range 69 West of the 6 th Principal Meridian, in Larimer County, Fort Collins, Colorado. Refer to Appendix A for the site vicinity map. Lake Street (Lake) to the north, South College Avenue (College) to the east, West Prospect Road (Prospect) to the south, and the Mason Street Corridor Transitway to the west border the property. Colorado State University (CSU) is located to the north and west of the site. Developed commercial and residential areas are to the east and south of the site. The site is located in the Mason Street Outfall (MSO) study performed by Ayres Associates in 2012. The design requirements and constraints are outline in the study. The site is approximately 5.7 acres of developed residential properties with an alley bisecting the lot from north to south. The site currently drains in several directions with most of the flow directed to the south with slopes from 1.9% to 2.5% and east at a slope of 1.2% to the intersection of Prospect and College. A smaller portion of the site drains to the north at a 2.0% slope to Lake and to the west at a slopes ranging from 1.8% to 3.8% to Mason Street. From the geotechnical report dated August 18, 2015 the soil is mainly sandy clay with areas of gravely sand and existing fill. Sandstone bedrock was encountered at 18ft to 24ft below the ground surface with ground water being located at 12ft to 19ft below ground surface. According to the FEMA Flood Insurance Rate Map Panel Number 08069C0979H dated 05/02/2012, the site is located outside of the 100-year floodplain area. The map panel is attached in Appendix A. Runoff from the existing site enters into the existing storm sewer system at inlets on Lake Street, Mason Street, and on Prospect just west of College. Currently, as stated in the MSO, the pipe system at Prospect is too small to handle the existing flows and water ponds at the intersection of College and Prospect. Flows that are not captured on Lake Street are directed onto College Avenue and eventually to the inlets on West Prospect Road. The MSO collects water on the Mason Street Corridor. The site construction includes approximately 41,300sqft building footprint and 27,000sqft parking lot areas with associated utilities, roads, sidewalks, detention pond, and landscaped and plaza areas. A portion of the property located in the northeast corner of the site will not be developed at this time. However, the storm system was designed to accommodate future development of that area as a parking lot. The site drains to the southwest corner of the property where the detention pond is located. The detention pond connects to the existing MSO storm system which outlets into a regional detention pond and eventually to Spring Creek and the Poudre River. Storm inlets and pipes are located throughout the site to capture and convey runoff to the detention pond. The main purpose of this study was to analyze the existing and developed drainage patterns in order to convey stormwater into the MSO as required by the MSO study. The proposed scope of work will include new stormwater piping and site grading to accommodate onsite detention pond and conveyance of the stormwater runoff to the existing storm system. An outlet structure consisting of a pipe with a restrictor plate will be installed in the pond to control the 100-year storm outflow rate. Colorado State University Health and Medical Center Preliminary Drainage Report Page 5 of 13 DRAINAGE BASINS AND HISTORIC RUNOFF HISTORIC DRAINAGE The existing system was modeled in SWMM by Ayres Associates for the CSU Medical Center Project Drainage Memo dated July 30, 2015. The Ayres SWMM model was used for the existing system analysis. Attached in Appendix A is Ayres SWMM model plan view, the SWMM results are attached in Appendix B. The site is within parts of historical basins E1, E2, E3, E4, E5 and E6. Basin E1 drains to the north into Lake Street and is collected by inlets on Lake Street. Basin E2 drains to the east onto College. The flow then travels south along College until it turn west onto Prospect which has a set of sump inlet approximately 50ft west of College. Basin E3 and E4 drain to the west on the MSO where inlets on the MSO collect the flow. Basins E5 and E6 drain south onto Prospect where there is a set of sump inlets. Currently the pipe system that the Prospect inlets tie into is undersized and ponding occurs for larger storm events. There is no existing onsite detention for the site. Table 1. Historic SWMM Basin Properties and Flows Drainage Basin Design Point Area (acre) % Impervious Width (ft) Slope (%) Q-100 (cfs) Runoff Coefficient E1 Lake St 0.92 39.0% 200 2.0 6.4 0.76 E2 College 1.13 49.0% 328 1.20 8.8 0.80 E3 Traintracks 0.67 50.0% 450 1.80 6.1 0.81 E4 Traintracks 0.34 0.0% 294 3.80 2.8 0.64 E5 Prospect 1.86 22.0% 809 2.50 13.8 0.71 E6 Prospect 0.89 18.0% 516 1.90 6.7 0.69 Total 5.81 31.3% 44.7 0.74 Colorado State University Health and Medical Center Preliminary Drainage Report Page 6 of 13 Figure 1. Historic Drainage Basins (Ayres Associates SWMM Model) Colorado State University Health and Medical Center Preliminary Drainage Report Page 7 of 13 DRAINAGE DESIGN CRITERIA HYDROLOGIC METHOD AND DESIGN STORM FREQUENCIES The drainage for the site was designed to meet or exceed the City of Fort Collin’s Standards and Specifications, including the Stormwater Criterial Manual which incorporates most of the Urban Drainage and Flood Control District Criteria Manual (USDCM). The US Environmental Protection Agency’s (EPA) Stormwater Management Model Version 5.1 (SWMM) was used to calculate the existing and proposed runoff rates and coefficients. The basin percent impervious values were calculated using impervious values from Table RO-3 in the USDCM. The City of Fort Collins’ Stormwater Criteria Manual recommended values for the SWMM basin properties and Table RA-9 provides a 100-year event rainfall intensity duration curve that were used in the SWMM model. HYDRAULIC CRITERIA The proposed drainage facility has been designed to comply with the City of Fort Collins Stormwater Criteria Manual. SWMM was used to design the storm system, outlet structure, and ponds. UDFCD’s UD-Inlet v3.14 spreadsheet was used to design the inlet structures for the site. The SWMM results and inlet design calculations are attached in Appendix B. Complete drainage plans, details, dimensions, etc. are included in the grading and drainage plans are attached in the construction documents. VARIANCES FROM THE CRITERIA As stated by Shane Boyle with the City of Fort Collins, if the site remains a CSURF property then the City’s low impact development (LID) and paver standards must be met. Since the entire site will be CSU property, the LID and paver criteria is not required. The meeting minutes and notes are attached in Appendix A. The MSO system includes 0.25acre-ft of water quality capture volume (WQCV) for this site in the regional detention pond. This site has a WQCV of 0.129acre- ft. Therefore, no water quality control is required on site. The minor storm event was also not controlled on site and the system was designed to capture and convey the 100-year event with flooding. DRAINAGE FACILITY DESIGN GENERAL CONCEPT The storm drainage system has been designed to convey the 100-year event through the combination of inlets, storm sewer pipes, a detention pond and an outlet pipe. A SWMM model was created to model the proposed subbasins and storm system. The site was graded to capture runoff into the storm system and into the detention pond located in the southwest corner of the site. The site was graded to minimize the amount of flow being directed to College and Prospect. An inlet was added to College to capture flow and reduce the runoff going to the Prospect inlets. While the College inlet is not collecting runoff from the developed site it is capturing flow that would eventually reach the Prospect inlets. Most of the runoff that was originally directed into the Mason Street Corridor is now captured in the sites system. Two inlets were added to Lake to Colorado State University Health and Medical Center Preliminary Drainage Report Page 8 of 13 capture the runoff from the site that could not be graded towards the detention pond. The inlets will reduce the flow that is directed to the existing undersized inlets on Lake located near College. PROPOSED DEVELOPED SUBBASINS The site was delineated into fifteen subbasin, D1-D15, and were dependent on the location of the inlets throughout the site. The roof drains split the roof into ten subbasins. There are only three Subbasins D7, D8, and D15 that are not captured and conveyed to the detention pond. Subbasin D7 drains to the Prospect inlets, D8 drains to College and eventually flows to the Prospect inlets, and D15 drains to the existing inlets on Lake. There are 10 roof drains that tie into the storm system. The developed drainage map is provided in Appendix C. Figure 2. Developed Drainage Subbasins (SWMM Model) Colorado State University Health and Medical Center Preliminary Drainage Report Page 9 of 13 SUBBASIN DESCRIPTIONS: • Subbasin D1 contains the north half of Lake Street and drains to a 5ft Type R inlet on Lake Street. • Subbasin D2 contains the south half of Lake and the sidewalk and landscaped area along the north edge of the parking lot. Part of the site that will be undeveloped is also in this subbasin. A 5ft Type R inlet was placed in Lake Street to capture the runoff. • Subbasin D3 contains the sites main parking lot, access roads, and part of the undeveloped area. The subbasin drains into a 10ft Type R inlet. • Subbasin D4 contains a small parking area, landscaping, and sidewalk. The runoff is directed away from the building into the parking area and a 5ft Type R inlet. • Subbasin D5 contains a small parking lot area, landscaping and sidewalk. The runoff is directed away from the building into the parking area and a 5ft Type R inlet. • Subbasin D6 contains the detention pond, sidewalk and plaza area and landscaping. The runoff is directed away from the building and into the detention pond. • Subbasin D7 contains the sidewalk, bus pull out area, landscaping and the widened Prospect Road area. This flow is not captured, but flows south onto Prospect and is directed east to the existing inlets on Prospect. • Subbasin D8 contains the sidewalk and landscaping. This flow is not captured, but flows east onto College and onto Prospect to the existing inlets on Prospect. • Subbasin D9 contains a plaza sitting area and landscaping. This flow is captured by a 18”x18” area drain. • Subbasin D10 contains parking spaces, sidewalk, and service area. This flow is directed to a 5ft Type R inlet. • Subbasin D11 contains the east section of the undeveloped area of the site. The runoff flows to the east onto College and is captured by 5ft Type R inlet on College which is connected to the sites storm system. The pipe the inlet is connected to can flow full at 3.5cfs. • Subbasin D12 contains a landscaped area, sidewalk and depression storage area. The depression area is designed to reduce the amount of runoff reaching Prospect. A 12”x12” area drain is located at the bottom of the depression and is piped into the detention pond. • Subbasin D13 contains part of the plaza located to the southeast of the building. This flow is captured by a 18”x18” area drain. • Subbasin D14 contains sidewalk and a depression storage area. The depression area keeps runoff from flowing west onto the Mason Street Corridor. A 12”x12” area drain is location at the bottom of the depression area and the drain ties into the storm system. • Subbasin D15 contains sidewalk and landscaping along the south side of Lake Street. This basin was included in the runoff calculations because the sidewalk width is being increased in this area. This flow will drain to the North onto Lake Street and into the existing inlets on Lake Street. • Roof Drain Subbasin: SD1, SD2, SD3, SD4, SD5, SD6, SD7, SD9, SD10, SD11. The roof drain locations, basin areas, and pipe sizes were supplied by the building architect. All the roof drains were tied into the storm system and drain to the detention pond. Colorado State University Health and Medical Center Preliminary Drainage Report Page 10 of 13 Table 2.Developed SWMM Subbasin Properties, Flows, and Runoff Coefficients Drainage Subbasin Design Point Area (acre) % Impervious Q-100 (cfs) Runoff Coefficient Discharge Location D1 1 0.14 100 1.3 0.98 Detention Pond D2 2 0.41 74.5 3.6 0.89 Detention Pond D3 3 0.96 72.1 8.9 0.88 Detention Pond D4 4 0.24 81.8 2.4 0.92 Detention Pond D5 5 0.32 84.9 3.2 0.93 Detention Pond D6 6 0.60 36.3 5.1 0.75 Detention Pond D7 7 0.45 80.0 4.1 0.91 Prospect D8 8 0.30 39.6 1.9 0.74 College D9 9 0.09 61.5 0.8 0.85 Detention Pond D10 10 0.35 93.6 3.5 0.96 Detention Pond D11 11 0.39 49.9 2.7 0.78 Detention Pond D12 12 0.23 35.1 1.9 0.75 Detention Pond D13 13 0.07 100 0.7 0.98 Detention Pond D14 14 0.16 44.9 1.3 0.78 Detention Pond D15 15 0.05 64.5 0.5 0.86 Lake Street SD1 SD1 0.13 90 1.3 0.95 Detention Pond SD2 SD2 0.13 90 1.3 0.95 Detention Pond SD3 SD3 0.15 90 1.5 0.95 Detention Pond SD4 SD4 0.08 90 0.8 0.95 Detention Pond SD5 SD5 0.03 90 0.3 0.95 Detention Pond SD6 SD6 0.09 90 0.9 0.95 Detention Pond SD7 SD7 0.19 90 1.9 0.95 Detention Pond SD9 SD9 0.04 90 0.4 0.95 Detention Pond SD10 SD10 0.05 90 0.5 0.95 Detention Pond SD11 SD11 0.04 90 0.4 0.95 Detention Pond Total/Weighted Avg 5.70 69.9 51.0 0.87 PROPOSED DETENTION POND A detention pond has been designed to capture the 100-year stormwater runoff on the site and discharge into the MSO system. Due to the existing grade of the site the entire site runoff was not captured and conveyed to the detention pond. The ponds outflow rate cannot exceed 11cfs and must tie into an existing MSO manhole at an elevation 4989.17ft. The bottom of the pond is at elevation 4989.5ft. Access to the bottom of the pond and outlet pipe is located in the center of the pond with the outlet pipe directed to the west. There are retaining walls on the north and east edge of the pond. The detention pond has a total volume of 0.867acre-ft including approximately 1.0ft of freeboard and has a top of pond elevation of 4997.0ft. For the 100-year event the pond will have a maximum Colorado State University Health and Medical Center Preliminary Drainage Report Page 11 of 13 water surface elevation of 4996.04ft which is a pond volume of approximately 0.599acre-ft. The maximum pond outflow rate is 10.76cfs with the outlet pipe having an outlet pipe of 2.0ft with a restrictor plate reducing the diameter to 1.65ft. There is very minimal flooding, 0.164ft 3 or 0.07cfs, at the inlet on College. There will be no water quality control in the detention pond because it will be controlled in the MSO’s regional detention pond. The development of the site will allow for all but 6.39cfs of runoff from the site to be captured in the detention facility and reduce the runoff that currently flows offsite. At this time the existing three properties on the northeast edge of the site will not be developed. However, in the future the properties may be purchased by CSU and developed. The current storm system and detention pond was sized to allow for the addition of this area as a parking lot. It was assumed that the backyard area of the properties would become impervious. This would increase the percent imperviousness for subbasin D2 to 79.4% and D3 to 92.7%, all other basin attributes would not change. The future changes were modeled and showed no flooding of the storm system and the ponds new water surface elevation will be at 4996.08ft which is a depth of 6.58ft above the pond bottom. The detention pond for the future development will have 100-year a peak volume will of 0.608ac-ft at an outflow rate of 10.98cfs. HISTORIC/DEVELOPED BASIN COMPARISON The site contains six historical basins which drain flow all directions, but the bulk of the site drains to College and Prospect where there are existing inlets on Prospect. The developed drainage basins will not drastically alter the historical drainage paths, but do decrease the peak flow rates. Flow to the existing Lake Street inlets decrease from 6.44cfs to 0.47cfs with the installation of two inlets on the north and south sides of Lake Street. Flow to College decreases from 8.82cfs to 1.86cfs with the addition of area drains in the plaza area and an inlet on College. The inlet on College will be able to capture 3.52cfs, restricted by the downstream 12inch pipe, which is more than the estimated runoff from the northeast undeveloped portion of the site at 2.66cfs. Only a small portion of the site now flows onto Prospect, the flow decreases from 20.48cfs to 4.06cfs. The proposed total 100-year peak runoff for the site is 51.0cfs with only 6.39cfs of that flow not being captured and conveyed to the detention pond. The detention pond has a release rate of 10.76cfs. Therefore, the total flow off the site from the detention pond and the non-captured flow is 17.15cfs. The existing site has a peak 100-year runoff rate of 44.66cfs. In the event that the detention ponds outlet pipe is clogged and the pond overflows the water will drain into Prospect and flow east towards College and the Prospect inlets. STORM WATER MODELING The pipes, perimeter drains, inlets, and detention pond have been designed to convey the 100-year storm event flows without flooding the systems. The system has been modeled in SWMM to analyze the conveyance and capacity of the pipe system and detention pond. A copy of the SWMM model will be provided upon request. The detentions pond outlet was assumed to have constant water surface elevation of 4995.1ft. This is the elevation of the 100-year hydraulic grade line in the MSO manhole that the detention pond outlets into. If the outlet pipe becomes clogged the pond will overflow to the south onto Prospect. Colorado State University Health and Medical Center Preliminary Drainage Report Page 12 of 13 STORMWATER POLLUTION PREVENTION/EROSION CONTROL TEMPORARY EROSION CONTROL A temporary erosion control plan is to be implemented for the site during construction. Temporary erosion control measures include, but not limited to, slope and swale protection provided by the use of erosion control wattles/sediment control logs, inlet and outlet protection, vehicle tracking control at access points to the site and silt fence surrounding the disturbed area. All temporary erosion control measures are to be removed after they are deemed unnecessary. Refer to the Erosion Control Plan for the CSU Medical Center Building for additional detail information. PERMANENT EROSION CONTROL Permanent erosion control measures include, but not limited to, the constructed detention ponds, riprap pads placed for culvert outlet protection, seeding and mulch placed to enable and established vegetative growth, etc. Long-term maintenance of these erosion control measures shall be the responsibility of the owner of the property. A general erosion control plan has been provided in the construction documents and is attached. CONCLUSIONS This Final Drainage Report for the CSU Health and Medical Center has been prepared to comply with the stormwater criteria set by the USDCM and City of Fort Collins. The proposed drainage system presented in this report is designed to convey the 100-year peak stormwater runoff through the site to the proposed detention ponds. Through calculations, modeling, and review of the proposed storm drain system, there appears to be adequate capacity to convey the proposed flows. This report also proposes best management practices for erosion control, permanent landscaping, riprap, and on-site construction facilities. It can therefore be concluded that development of the detention ponds comply with all of the stormwater jurisdictional criteria and will not adversely affect the existing streets, storm drain system and/or detention/water quality facilities. REFERENCES 1. Urban Storm Drainage Criteria Manual (Volumes 1, 2, and 3), Urban Drainage and Flood Control District, June 2001, Revised April 2008. 2. City of Fort Collins Stormwater Criteria Manual, City of Fort Collins, December 2011. 3. “Geotechnical Investigation Proposed Medical Center Colorado State University Fort Collins, Colorado”, CTL Thompson Incorporated, Dated August 18, 2015. 4. “CSU Medical Center Project Drainage Memo”, Ayres Associates, Dated July 30, 2015. Colorado State University Health and Medical Center Preliminary Drainage Report Page 13 of 13 5. “Alternative Analysis for the Design of the Mason Street Outfall Study”, Ayres Associates, Dated November 2010. 6. Stormwater Management Model User’s Manual Version 5.0, U.S. Environmental Protection Agency, Revised July 2010. 7. Stormwater Management Model Applications Manual, U.S. Environmental Protection Agency, July 2009. APPENDIX A – REFERENCE INFORMATION 1. Urban Storm Drainage Criteria Manual Table RO-3 2. CSU Medical Center Project Drainage Memo from Ayres Associates Dated July 31, 2015 3. SPAR Comments and Meeting Minutes dated February 9, 2015 4. Geotechnical Soils Results and Soils Boring Logs 5. FEMA FIRM MAP DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Table RO-3—Recommended Percentage Imperviousness Values Land Use or Surface Characteristics Percentage Imperviousness Business: Commercial areas 95 Neighborhood areas 85 Residential: Single-family * Multi-unit (detached) 60 Multi-unit (attached) 75 Half-acre lot or larger * Apartments 80 Industrial: Light areas 80 Heavy areas 90 Parks, cemeteries 5 Playgrounds 10 Schools 50 Railroad yard areas 15 Undeveloped Areas: Historic flow analysis 2 Greenbelts, agricultural 2 Off-site flow analysis (when land use not defined) 45 Streets: Paved 100 Gravel (packed) 40 Drive and walks 90 Roofs 90 Lawns, sandy soil 0 Lawns, clayey soil 0 * See Figures RO-3 through RO-5 for percentage imperviousness. C A = K A + ( 1 . 31 i 3 − 1 . 44 i 2 + 1 . 135 i − 0 . 12 ) for CA ≥ 0, otherwise CA = 0 (RO-6) C CD = K CD + ( 0 . 858 i 3 − 0 . 786 i 2 + 0 . 774 i + 0 . 04 ) (RO-7) C B = (CA + C CD ) 2 2007-01 RO-9 Urban Drainage and Flood Control District 400 North Link Lane | Fort Collins, Colorado 80524 Telephone: 970-206-9455 Fax: 970-206-9441 GEOTECHNICAL INVESTIGATION PROPOSED MEDICAL CENTER COLORADO STATE UNIVERSITY FORT COLLINS, COLORADO COLORADO STATE UNIVERSITY 251 Edison, 6030 Campus Delivery Fort Collins, Colorado 80526-6030 Attention: Mr. Milt Brown Project Manager Project No. FC07034-125 August 18, 2015 COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 TABLE OF CONTENTS SCOPE 1 SUMMARY OF CONCLUSIONS 1 SITE CONDITIONS AND PROPOSED CONSTRUCTION 2 INVESTIGATION 3 SUBSURFACE CONDITIONS 3 SITE DEVELOPMENT 4 Fill Placement 4 Excavations 6 FOUNDATIONS 6 Spread Footings with Minimum Deadload 6 Drilled Piers Bottomed in Bedrock 7 Laterally Loaded Piers 8 Closely Spaced Pier Reduction Factors 9 BELOW GRADE AREAS 10 FLOOR SYSTEMS 10 PAVEMENTS 13 Pavement Selection 14 Subgrade and Pavement Materials and Construction 14 Pavement Maintenance 14 WATER-SOLUBLE SULFATES 15 SURFACE DRAINAGE 16 FIGURE 1 – LOCATIONS OF EXPLORATORY BORINGS FIGURES 2 THROUGH 4 – SUMMARY LOGS OF EXPLORATORY BORINGS APPENDIX A – RESULTS OF LABORATORY TESTING APPENDIX B – SAMPLE SITE GRADING SPECIFICATIONS APPENDIX C – PAVEMENT CONSTRUCTION RECOMMENDATIONS APPENDIX D – PAVEMENT MAINTENANCE PROGRAM COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 1 SCOPE This report presents the results of our Geotechnical Investigation for the proposed Colorado State University Medical Center in Fort Collins, Colorado. The purpose of the investigation was to evaluate the subsurface conditions and provide foundation recommendations and geotechnical design criteria for the pro- ject. The scope was described in our Service Agreement (FC-15-0245, dated July 8, 2015). The report was prepared from data developed during field exploration, la- boratory testing, engineering analysis and experience with similar conditions. The report includes a description of subsurface conditions found in our explora- tory borings and discussions of site development as influenced by geotechnical considerations. Our opinions and recommendations regarding design criteria and construction details for site development, foundations, floor systems, slabs- on-grade, pavements and drainage are provided. If the proposed construction changes, we should be requested to review our recommendations. Our conclu- sions are summarized in the following paragraphs. SUMMARY OF CONCLUSIONS 1. In general, soils encountered in our borings consisted of sandy clay. A layer of gravelly sand was encountered in three of our bor- ings below and/or within the clay layer. Sandstone bedrock was encountered in eight of our borings at depths of 18 to 24 feet to the depths explored. 2. Groundwater was encountered in eight borings at depths of 12 to 19 feet during drilling and 11 to 16½ feet when measured several days later. Existing groundwater levels are not expected to signifi- cantly affect the proposed construction, but may affect drilled pier installation. 3. Existing fill was encountered in our borings. Several structures were still located on the site that will be demolished prior to con- COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 2 struction. All structures should be completely removed below im- provements. The existing fill should be completely removed and re- compacted below the proposed building. 4. We believe the proposed structure can be constructed on spread footing foundations with a minimum dead load placed on natural, undisturbed soil and/or properly compacted fill or a drilled pier foun- dation bottomed into bedrock. Foundation design and construction recommendations are presented in this report. 5. The presence of expansive soils and bedrock constitutes a geologic hazard. There is risk that slabs-on-grade and foundations will heave or settle and be damaged. We believe the recommendations presented in this report will help to control risk of damage; they will not eliminate that risk. Slabs-on-grade and, in some instances, foundations may be damaged. 6. We believe a slab-on-grade floor is appropriate for this site. Some movement of slab-on-grade floors should be anticipated. We ex- pect movements will be minor, on the order of 1 inch or less. If movement cannot be tolerated, structural floors should be consid- ered. 7. Pavement areas including parking and access drives are planned for this project. Four borings were drilled in the area of the pro- posed pavements. Pavement section recommendations are in- cluded in this report. SITE CONDITIONS AND PROPOSED CONSTRUCTION The site is located northwest of Prospect Road and College Avenue in Fort Collins, Colorado (Figure 1). Several vacant residences are located at the site that are to be demolished. We understand the proposed construction will in- clude a new Medical Center. The 4-story Medical Center will be approximately 120,000 square feet. Associated pavement areas will included parking and ac- cess drives. APPENDIX B – HYDRAULIC/HYDROLOGIC COMPUTATIONS 1. SWMM Input Table (Historic – Ayres Associates Data) 2. SWMM Results (Historic – Ayres Associates Model) 3. SWMM Input Table (Developed) 4. SWMM Results (Developed) 5. Inlet Sizing Calculations JVA Incorporated Job Name: CSU Medical Center 25 Old Town Square Job Number: 2487c Fort Collins, CO 80524 Date: 11/10/15 Ph: 970.225.9099 By: LAT Fax: 970.225.6923 CSU Medical Center Historic SWMM Input Values for Subbasins (Ayres Associates Model) Location: Fort_Collins Major Design Storm: 100 Soil Type: C/D Subbasin Area Width Slope % Impervious ID (acre) (ft) (%) (%) E1 LakeSt 0.92 200 2.0 39.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 E2 College 1.13 328 1.2 49.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 E3 Traintracks 0.67 450 1.8 50.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 E4 Traintracks 0.34 294 3.8 0.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 E5 Prospect 1.86 809 2.5 22.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 E6 Prospect 0.89 516 1.9 18.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 Total 5.81 Weighted Avg 31.3 HORTON Outlet N-Imperv N-Perv Dstor- Imperv Dstor- Perv % Zero- Imperv Subarea Routing Percent Routed Max Infiltration Min Infiltration Decay Constant Drying Time JVA Incorporated Job Name: CSU Medical Center 25 Old Town Square Job Number: 2487c Fort Collins, CO 80524 Date: 11/10/15 Ph: 970.225.9099 By: LAT Fax: 970.225.6923 CSU Medical Center Historic Runoff Coefficient & Time of Concentration SWMM Result Summary from Ayres Associates SWMM Model Location: Fort_Collins Major Design Storm: 100 Soil Type: C/D Basin Name Outlet Total Area (acre) Runoff Coeff's Flow Rate (cfs) E1 LakeSt 0.92 0.76 6.4 E2 College 1.13 0.80 8.8 E3 Traintracks 0.67 0.81 6.1 E4 Traintracks 0.34 0.64 2.8 E5 Prospect 1.86 0.71 13.8 E6 Prospect 0.89 0.69 6.7 TOTAL SITE 5.81 0.74 44.7 Copy of 2487c - Rational Calculations LAT.xlsx Historic -Results Summary Page 1 of 1 JVA Incorporated Job Name: CSU Medical Center 25 Old Town Square Job Number: 2487c Fort Collins, CO 80524 Date: 11/10/15 Ph: 970.225.9099 By: LAT Fax: 970.225.6923 CSU Medical Center Historic Runoff Coefficient & Time of Concentration SWMM Result Summary from Ayres Associates SWMM Model Location: Fort_Collins Major Design Storm: 100 Soil Type: C/D Subbasin ID Outlet Total Area (acre) Runoff Coeff's C100 Flow Rates (cfs) Q100 NOTES D1 C1A 0.14 0.98 1.3 To Lake Captured D2 C2A 0.41 0.89 3.6 To Lake Captured D3 C3A 0.96 0.88 8.9 D4 C4A 0.24 0.92 2.4 D5 C5A 0.32 0.93 3.2 D6 POND 0.60 0.75 5.1 Detention Pond D7 Prospect 0.45 0.91 4.1 To Prospect Not Captured D8 College 0.30 0.74 1.9 To College Not Captured D9 C3C 0.09 0.85 0.8 D10 C1B 0.35 0.96 3.5 D11 C2B 0.39 0.78 2.7 To College Captured D12 C1C 0.23 0.75 1.9 D13 C2C 0.07 0.98 0.7 D14 C1D 0.16 0.78 1.3 D15 Lake 0.05 0.86 0.5 To Lake Not Captured SD1 RD10 0.13 0.95 1.3 SD2 RD9 0.13 0.95 1.3 SD3 RD7 0.15 0.95 1.5 SD4 RD6 0.08 0.95 0.8 SD5 RD5 0.03 0.95 0.3 SD6 RD3 0.09 0.95 0.9 SD7 RD1 0.19 0.95 1.9 SD9 RD8 0.04 0.95 0.4 SD10 RD4 0.05 0.95 0.5 SD11 RD2 0.04 0.95 0.4 5.70 51.0 Weighted Runoff Coefficient 0.87 TOTAL Subcatchment Runoff Summary Total Total Total Total Total Total Peak Precip Runon Evap Infil Runoff Runoff Runoff Runoff Subcatchment in in in in in 10^6 gal CFS Coeff E1 3.67 0.00 0.00 0.89 2.77 0.07 6.44 0.756 E2 3.67 0.00 0.00 0.73 2.92 0.09 8.82 0.797 E3 3.67 0.00 0.00 0.68 2.98 0.05 6.14 0.812 E4 3.67 0.00 0.00 1.37 2.34 0.02 2.78 0.637 E5 3.67 0.00 0.00 1.10 2.58 0.13 13.80 0.705 E6 3.67 0.00 0.00 1.15 2.54 0.06 6.68 0.692 SWMM 5.1 Page 1 JVA Incorporated Job Name: CSU Medical Center 25 Old Town Square Job Number: 2487c Fort Collins, CO 80524 Date: 11/10/15 Ph: 970.225.9099 By: LAT Fax: 970.225.6923 CSU Medical Center Developed SWMM Input Values for Subbasins Location: Fort_Collins Major Design Storm: 100 Soil Type: C/D Subbasin Area Width Slope % Impervious ID (acre) (ft) (%) (%) D1 C1A 0.14 20 1.3 100.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D2 C2A 0.41 60 1.4 74.5 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D3 C3A 0.96 220 2.2 72.1 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D4 C4A 0.24 120 2.1 81.8 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D5 C5A 0.32 90 2.5 84.9 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D6 POND 0.60 190 6.3 36.3 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D7 Prospect 0.45 60 1.6 80.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D8 College 0.30 40 2.0 39.6 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D9 C3C 0.09 60 1.1 61.5 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D10 C1B 0.35 100 2.0 93.6 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D11 C2B 0.39 70 0.8 49.9 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D12 C1C 0.23 80 5.5 35.1 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D13 C2C 0.07 50 0.5 100.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D14 C1D 0.16 50 1.5 44.9 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 D15 Lake 0.05 30 1.1 64.5 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 SD1 RD10 0.13 150 3.0 90.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 SD2 RD9 0.13 70 3.0 90.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 SD3 RD7 0.15 150 3.0 90.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 SD4 RD6 0.08 70 3.0 90.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 SD5 RD5 0.03 30 3.0 90.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 SD6 RD3 0.09 50 3.0 90.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 SD7 RD1 0.19 150 3.0 90.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 SD9 RD8 0.04 20 3.0 90.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 SD10 RD4 0.05 40 3.0 90.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 SD11 RD2 0.04 30 3.0 90.0 0.016 0.25 0.1 0.3 25 OUTLET 100 0.51 0.5 6.48 7 Total 5.70 69.9 Outlet N-Imperv HORTON Weighted Avg Subarea Routing % Zero- Imperv Dstor-Perv Dstor- Imperv N-Perv Drying Time Decay Constant Min Infiltration Max Infiltration Percent Routed JVA Incorporated Job Name: CSU Medical Center 25 Old Town Square Job Number: 2487c Fort Collins, CO 80524 Date: 11/10/15 Ph: 970.225.9099 By: LAT Fax: 970.225.6923 CSU Medical Center Developed Percent Impervious Calculations Location: Fort_Collins Major Design Storm: 100 Soil Type: C/D I (%) = 100% 100% 90% 40% 10% 0% Basin Name Design Point Apaved streets (sf) Adrives/c onc (sf) Aroof (sf) Agravel (sf) Aplygnd (sf) Alscape (C/D soil) (sf) ATotal (sf) ATotal (ac) Imp (%) D1 1 4,973 1,024 5,997 0.14 100.0% D2 2 7,235 5,812 304 4,537 17,888 0.41 74.5% D3 3 23,507 6,349 375 11,653 41,884 0.96 72.1% D4 4 4,637 3,889 1,892 10,418 0.24 81.8% D5 5 7,511 4,165 2,076 13,752 0.32 84.9% D6 6 9,485 16,635 26,120 0.60 36.3% D7 7 6,313 9,383 3,921 19,617 0.45 80.0% D8 8 345 4,766 7,797 12,908 0.30 39.6% D9 9 2,307 1,446 3,753 0.09 61.5% D10 10 11,736 2,706 981 15,423 0.35 93.6% D11 11 4,530 4,470 8,152 17,152 0.39 49.9% D12 12 3,528 6,509 10,037 0.23 35.1% D13 13 2,855 2,855 0.07 100.0% D14 14 3,079 3,779 6,858 0.16 44.9% D15 15 1,530 842 2,372 0.05 64.5% SD1 SD1 5,880 5,880 0.13 90.0% SD2 SD2 5,749 5,749 0.13 90.0% SD3 SD3 6,693 6,693 0.15 90.0% SD4 SD4 3,516 3,516 0.08 90.0% SD5 SD5 1,483 1,483 0.03 90.0% SD6 SD6 3,824 3,824 0.09 90.0% SD7 SD7 8,297 8,297 0.19 90.0% SD9 SD8 1,802 1,802 0.04 90.0% SD10 SD9 2,303 2,303 0.05 90.0% SD11 SD10 1,728 1,728 0.04 90.0% JVA Incorporated Job Name: CSU Medical Center 25 Old Town Square Job Number: 2487c Fort Collins, CO 80524 Date: 11/10/15 Ph: 970.225.9099 By: LAT Fax: 970.225.6923 CSU Medical Center Developed Runoff Coefficient & Time of Concentration SWMM Result Summary Location: Fort_Collins Major Design Storm: 100 Soil Type: C/D Subbasin ID Outlet Total Area (acre) Runoff Coeff's C100 Flow Rates (cfs) Q100 NOTES D1 C1A 0.14 0.98 1.3 To Lake Captured D2 C2A 0.41 0.89 3.6 To Lake Captured D3 C3A 0.96 0.88 8.9 D4 C4A 0.24 0.92 2.4 D5 C5A 0.32 0.93 3.2 D6 POND 0.60 0.75 5.1 Detention Pond D7 Prospect 0.45 0.91 4.1 To Prospect Not Captured D8 College 0.30 0.74 1.9 To College Not Captured D9 C3C 0.09 0.85 0.8 D10 C1B 0.35 0.96 3.5 D11 C2B 0.39 0.78 2.7 To College Captured D12 C1C 0.23 0.75 1.9 D13 C2C 0.07 0.98 0.7 D14 C1D 0.16 0.78 1.3 D15 Lake 0.05 0.86 0.5 To Lake Not Captured SD1 RD10 0.13 0.95 1.3 SD2 RD9 0.13 0.95 1.3 SD3 RD7 0.15 0.95 1.5 SD4 RD6 0.08 0.95 0.8 SD5 RD5 0.03 0.95 0.3 SD6 RD3 0.09 0.95 0.9 SD7 RD1 0.19 0.95 1.9 SD9 RD8 0.04 0.95 0.4 SD10 RD4 0.05 0.95 0.5 SD11 RD2 0.04 0.95 0.4 5.70 51.0 Weighted Runoff Coefficient 0.87 TOTAL Subcatchment Runoff Summary Total Total Total Total Total Total Peak Precip Runon Evap Infil Runoff Runoff Runoff Runoff Subcatchment in in in in in 10^6 gal CFS Coeff D1 3.67 0.00 0.00 0.00 3.59 0.01 1.32 0.979 D10 3.67 0.00 0.00 0.09 3.52 0.03 3.47 0.958 D11 3.67 0.00 0.00 0.76 2.87 0.03 2.66 0.782 D12 3.67 0.00 0.00 0.90 2.75 0.02 1.94 0.749 D13 3.67 0.00 0.00 0.00 3.60 0.01 0.70 0.980 D14 3.67 0.00 0.00 0.78 2.85 0.01 1.25 0.778 D15 3.67 0.00 0.00 0.48 3.14 0.00 0.47 0.856 D2 3.67 0.00 0.00 0.36 3.25 0.04 3.58 0.886 D3 3.67 0.00 0.00 0.39 3.23 0.08 8.91 0.881 D4 3.67 0.00 0.00 0.24 3.37 0.02 2.37 0.918 D5 3.67 0.00 0.00 0.20 3.40 0.03 3.15 0.928 D6 3.67 0.00 0.00 0.88 2.76 0.05 5.07 0.753 D7 3.67 0.00 0.00 0.28 3.33 0.04 4.06 0.907 D8 3.67 0.00 0.00 0.92 2.72 0.02 1.86 0.741 D9 3.67 0.00 0.00 0.53 3.10 0.01 0.84 0.845 SD1 3.67 0.00 0.00 0.13 3.47 0.01 1.30 0.947 SWMM 5.1 Page 1 Total Total Total Total Total Total Peak Precip Runon Evap Infil Runoff Runoff Runoff Runoff Subcatchment in in in in in 10^6 gal CFS Coeff SD10 3.67 0.00 0.00 0.13 3.47 0.00 0.50 0.947 SD11 3.67 0.00 0.00 0.13 3.47 0.00 0.40 0.947 SD2 3.67 0.00 0.00 0.13 3.47 0.01 1.30 0.946 SD3 3.67 0.00 0.00 0.13 3.47 0.01 1.50 0.947 SD4 3.67 0.00 0.00 0.13 3.47 0.01 0.80 0.947 SD5 3.67 0.00 0.00 0.13 3.47 0.00 0.30 0.947 SD6 3.67 0.00 0.00 0.13 3.47 0.01 0.90 0.946 SD7 3.67 0.00 0.00 0.13 3.47 0.02 1.90 0.947 SD9 3.67 0.00 0.00 0.13 3.47 0.00 0.40 0.946 SWMM 5.1 Page 2 Node Depth Summary Average Maximum Maximum Day of Hour of Depth Depth HGL Maximum Maximum Node Type Feet Feet Feet Depth Depth C2B JUNCTION 0.75 2.62 4997.04 0 00:39 C1B JUNCTION 1.16 2.86 4996.82 0 00:39 C5A JUNCTION 1.42 2.42 4996.08 0 00:50 C4A JUNCTION 2.62 3.73 4996.07 0 00:50 C3A JUNCTION 2.03 3.39 4996.38 0 00:39 C2A JUNCTION 0.79 2.69 4997.06 0 00:39 C1A JUNCTION 0.53 2.52 4997.17 0 00:39 M1B JUNCTION 1.41 3.01 4996.68 0 00:39 J1A JUNCTION 3.31 4.46 4996.05 0 00:50 RD1 JUNCTION 0.05 0.49 4996.99 0 00:40 J11C JUNCTION 0.09 2.99 4999.95 0 00:38 J9C JUNCTION 0.05 0.45 4996.45 0 00:40 RD5 JUNCTION 0.82 2.28 4996.59 0 00:37 J10C JUNCTION 0.12 3.17 4999.79 0 00:38 RD6 JUNCTION 0.13 2.70 4997.82 0 00:37 J6C JUNCTION 1.18 2.51 4996.44 0 00:38 SWMM 5.1 Page 1 Average Maximum Maximum Day of Hour of Depth Depth HGL Maximum Maximum Node Type Feet Feet Feet Depth Depth J7C JUNCTION 0.85 2.90 4997.19 0 00:38 J1B JUNCTION 1.95 3.07 4996.14 0 00:39 RD10 JUNCTION 0.21 3.21 4998.27 0 00:39 C1C JUNCTION 4.12 5.32 4996.04 0 00:51 MH1A JUNCTION 2.87 4.01 4996.07 0 00:50 RD7 JUNCTION 0.46 3.26 4998.02 0 00:38 RD8 JUNCTION 0.13 2.98 4998.10 0 00:38 RD9 JUNCTION 0.08 3.92 4999.55 0 00:38 C2C JUNCTION 2.13 3.31 4996.17 0 00:38 C3C JUNCTION 1.08 2.36 4996.38 0 00:38 J4C JUNCTION 2.22 3.38 4996.15 0 00:38 J5C JUNCTION 1.26 2.50 4996.34 0 00:38 J8C JUNCTION 0.39 2.98 4997.78 0 00:38 J3C JUNCTION 2.43 3.53 4996.07 0 00:50 J2C JUNCTION 3.16 4.31 4996.05 0 00:50 J1C JUNCTION 4.54 5.77 4996.04 0 00:51 RD4 JUNCTION 0.04 0.98 4997.59 0 00:36 SWMM 5.1 Page 2 Average Maximum Maximum Day of Hour of Depth Depth HGL Maximum Maximum Node Type Feet Feet Feet Depth Depth RD3 JUNCTION 0.08 3.00 5000.20 0 00:38 RD2 JUNCTION 0.10 3.30 5000.30 0 00:38 C1D JUNCTION 0.13 1.02 4996.11 0 00:50 MH2A JUNCTION 3.94 5.13 4996.04 0 00:51 College OUTFALL 0.00 0.00 0.00 0 00:00 Prospect OUTFALL 0.00 0.00 0.00 0 00:00 EXMH OUTFALL 5.83 5.83 4995.10 0 00:00 Lake OUTFALL 0.00 0.00 0.00 0 00:00 POND STORAGE 5.28 6.54 4996.04 0 00:51 SWMM 5.1 Page 3 Node Flooding Summary Total Maximum Maximum Day of Hour of Flood Ponded Hours Rate Maximum Maximum Volume Depth Node Flooded CFS Flooding Flooding 10^6 gal Feet C2B 0.01 0.07 0 00:39 0.000 0.000 SWMM 5.1 Page 1 Link Flow Summary Maximum Day of Hour of Maximum Max / Max / |Flow| Maximum Maximum |Velocity| Full Full Link Type CFS Flow Flow ft/sec Flow Depth L6A CONDUIT 29.89 0 00:40 3.31 0.42 1.00 L5A-1 CONDUIT 24.07 0 00:40 3.63 0.51 1.00 L3A CONDUIT 14.12 0 00:40 4.19 0.49 1.00 L2A CONDUIT 5.66 0 00:40 3.93 0.52 1.00 L1A CONDUIT 1.36 0 00:39 2.31 0.54 1.00 L3B-2 CONDUIT 7.81 0 00:39 3.96 0.49 1.00 L2B CONDUIT 6.14 0 00:39 4.64 0.85 1.00 L1B CONDUIT 2.66 0 00:39 3.39 1.06 1.00 L5A-2 CONDUIT 25.97 0 00:40 3.89 0.55 1.00 LRD1 CONDUIT 1.89 0 00:38 8.16 0.68 0.87 LRD11 CONDUIT 1.78 0 00:39 6.91 0.45 0.84 LRD13 CONDUIT 0.40 0 00:38 2.04 0.71 1.00 LRD5 CONDUIT 0.31 0 00:37 3.16 0.30 1.00 LRD12 CONDUIT 1.30 0 00:39 7.12 2.26 0.95 L7C CONDUIT 4.26 0 00:39 4.13 0.40 1.00 L10C CONDUIT 1.76 0 00:38 2.97 0.49 1.00 SWMM 5.1 Page 1 Maximum Day of Hour of Maximum Max / Max / |Flow| Maximum Maximum |Velocity| Full Full Link Type CFS Flow Flow ft/sec Flow Depth L11C CONDUIT 1.35 0 00:38 3.50 0.38 1.00 L3B-1 CONDUIT 6.55 0 00:39 3.52 0.41 1.00 LRD10 CONDUIT 1.30 0 00:39 6.62 1.97 1.00 L2C CONDUIT 8.08 0 00:39 2.57 0.51 1.00 L4A CONDUIT 16.48 0 00:40 4.11 0.57 1.00 LRD8 CONDUIT 0.40 0 00:38 4.72 1.02 1.00 LRD7 CONDUIT 1.50 0 00:39 7.65 1.26 1.00 LRD6 CONDUIT 0.80 0 00:39 5.00 0.77 1.00 L6C CONDUIT 0.90 0 00:36 1.22 0.09 1.00 L8C CONDUIT 0.93 0 00:36 1.58 0.09 1.00 L9C CONDUIT 3.28 0 00:39 5.27 0.94 1.00 LRD9 CONDUIT 1.32 0 00:38 6.83 1.11 1.00 L5C CONDUIT 5.09 0 00:39 4.23 0.48 1.00 L4C CONDUIT 5.91 0 00:39 3.94 0.56 1.00 L3C CONDUIT 6.21 0 00:39 3.60 0.59 1.00 L1C CONDUIT 9.86 0 00:39 3.14 0.62 1.00 LRD2 CONDUIT 0.40 0 00:38 4.69 2.60 1.00 SWMM 5.1 Page 2 Maximum Day of Hour of Maximum Max / Max / |Flow| Maximum Maximum |Velocity| Full Full Link Type CFS Flow Flow ft/sec Flow Depth LRD3 CONDUIT 0.90 0 00:39 4.58 0.77 1.00 LRD4 CONDUIT 0.50 0 00:39 5.85 1.23 1.00 L1D CONDUIT 1.15 0 00:38 2.07 0.32 1.00 L2D CONDUIT 4.22 0 00:38 5.38 1.23 1.00 PONDOUT ORIFICE 10.76 0 00:51 1.00 SWMM 5.1 Page 3 Storage Volume Summary Average Average Evap Infil Maximum Maximum Day of Hour of Maximum Storage Volume Percent Percent Percent Volume Percent Maximum Maximum Outflow Unit 1000 ft3 Full Loss Loss 1000 ft3 Full Volume Volume CFS POND 16.753 44 0 0 26.075 68 0 00:51 10.76 SWMM 5.1 Page 1 JVA Incorporated Job Name: CSU Medical Center 25 Old Town Square Job Number: 2487c Fort Collins, CO 80524 Date: 11/11/15 Ph: 970.225.9099 By: LAT Fax: 970.225.6923 POND VOLUME CALCULATIONS - STAGE / STORAGE Pond Volume = Prismoidal Formula Volume Equation = (A1+A2+SQRT(A1*A2)*D/3 WEIGHTED INCREMENTAL CUMMULATIVE CUMMULATIVE ELEVATION DEPTH (D) AREA (A1) AVG AREA (A2) VOLUME VOLUME VOLUME Depth ft ft ft2 ft2 ft3 ft3 ACRE-FT ft 4989.5 0.0 0 0 0.00 0.00 4990.0 0.5 210 105 35 35 0.00 0.50 4991.0 1.0 1,324 767 687 722 0.02 1.50 4992.0 1.0 2,873 2,099 2,049 2,771 0.06 2.50 4993.0 1.0 3,958 3,416 3,401 6,172 0.14 3.50 4994.0 1.0 4,848 4,403 4,395 10,568 0.24 4.50 4995.0 1.0 7,246 6,047 6,007 16,575 0.38 5.50 4996.0 1.0 10,519 8,883 8,832 25,407 0.58 6.50 4997.0 1.0 14,324 12,422 12,373 37,779 0.87 7.50 Volume (ft 3 ) Volume (ac-ft) Water Surface Elevation Water Depth V100 26,075 cf 0.599 ac-ft 4996.04 ft 6.54 ft Top of Pond 37,779 cf 0.867 ac-ft 4997.00 ft 7.50 ft Volume Interpolation Calculations Vol Elev 25406.54 4996.00 26075.00 4996.04 37779.19 4997.00 Stage / Storage Input Table Volume Summary Table V100 2487c - Rational Calculations.xlsx Vol Pond Page 1 of 2 JVA Incorporated Job Name: CSU Medical Center 25 Old Town Square Job Number: 2487c Fort Collins, CO 80524 Date: 11/11/15 Ph: 970.225.9099 By: LAT Fax: 970.225.6923 Top of Pond 37,779 cf 4997.00 ft V100 26,075 cf 4996.04 ft 4989.0 4990.0 4991.0 4992.0 4993.0 4994.0 4995.0 4996.0 4997.0 4998.0 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 WATER SURFACE ELEVATION (FEET ABOVE MSL) POND VOLUME (CF) STAGE VS. STORAGE Detention Pond 2487c - Rational Calculations.xlsx Vol Pond Page 2 of 2 JVA Incorporated Job Name: CSU Medical Center 25 Old Town Square Job Number: 2487c Fort Collins, CO 80524 Date: 11/10/15 Ph: 970.225.9099 By: LAT Fax: 970.225.6923 FLOW CALCULATIONS - GRATE INLET SUMP CONDITION (Reference: Urban Drainage and Flood Control District Drainage Criteria Manual, 2001, V.1, Section 3.3.6) (Note: Spreadsheet assumes orifice condition for fully developed flow.) INLET TYPE: BASIN: Orifice Equation: Q = Cd*Ao*(2gH)^0.5 K = Clogging Coefficent value for multiple inlets Adjust Ao (open area) due to clogging as follows: N Grate 1 1 Effective Area Opening Ae = (1-C) Ao, where: 2 1.5 C = K * Co / N 3 1.75 N = Number of Inlets 4 1.88 Co = Single Inlet Clogging Factor: 5 1.94 Co(grate) = 0.5 (50% clogging) 6 1.97 7 1.98 8 1.99 Number of inlets: N = 1 Inlet Dimensions and Effective Open Area: Grate Opening: Ao(g) = 0.61 ft^2 Total Ao(g) = 0.61 ft^2 K = 1.00 C = K*Co/N = 0.50 Ae(g) = (1-C)Ao = 0.31 ft^2 Allowable depth: H = 3.0 in = 0.25 ft Constants: g = 32.20 ft/s^2 Cd = 0.67 Flow Calculations: Grate Flow: Q = Cd * Ae(g) * (2g*H)^0.5 Qg= 0.82 CFS Total Intercepted Flow with 1 inlet(s) and an allowable depth of 3 inches is 0.8 cfs Required Flow (Q 0.70 cfs Bypass = 0.0 cfs Required Flow (Q 0.84 cfs Bypass = 0.0 cfs 18" Area Drain D9 AND D13 C2C) = C3C) = Copy of 2487c - Rational Calculations LAT.xlsx 18" Area Drain(UDFCD) Page 1 of 1 JVA Incorporated Job Name: CSU Medical Center 25 Old Town Square Job Number: 2487c Fort Collins, CO 80524 Date: 11/11/15 Ph: 970.225.9099 By: LAT Fax: 970.225.6923 CSU Medical Center Water Quality Capture Volume (WQCV) Calculations (UDFCD Volume 3 Chapter 3) Location: Fort_Collins Major Design Storm: 100 Soil Type: C/D WQCV=a((0.91I 3 )-(1.19I 2 )+(0.78I)) Where: WQCV = Water Quality Capture Volume (watershed inches) a = Drain Time Coefficient (see table below ) I = Imperviousness (%/100) Drainage Time (hrs) Coefficient, a 12 0.8 24 0.9 40 1.00 WQCV North Basin: a= 1.00 I= 0.699 %/100 WQCV= 0.272 watershed inches Vrequired =(WQCV/12)*A*43560 WQCV= 0.272 watershed inches A = 5.70 acre Vrequired = 5621 cf 0.129 acre-ft Grass Type Limiting Manning's n A 0.06 B 0.04 C 0.033 D 0.03 E 0.024 Analysis of Trapezoidal Grass-Lined Channel Using SCS Method NRCS Vegetal Retardance (A, B, C, D, or E) A, B, C, D or E Manning's n (Leave cell D16 blank to manually enter an n value) n = 0.030 Channel Invert Slope SO = 0.0200 ft/ft Bottom Width B = 4.50 ft Warning 01 Left Side Slope Z1 = 0.17 ft/ft Warning 01 Right Side Slope Z2 = 0.25 ft/ft Check one of the following soil types: Soil Type: Max. Velocity (VMAX) Max Froude No. (FMAX) Sandy 5.0 fps 0.50 Non-Sandy 7.0 fps 0.80 Minor Storm Major Storm Max. Allowable Top Width of Channel for Minor & Major Storm TMAX = 20.00 20.00 feet Max. Allowable Water Depth in Channel for Minor & Major Storm dMAX = 2.11 2.11 feet Allowable Channel Capacity Based On Channel Geometry Minor Storm Major Storm MINOR STORM Allowable Capacity is based on Depth Criterion Qallow = 81.95 81.95 cfs MAJOR STORM Allowable Capacity is based on Depth Criterion dallow = 2.11 2.11 ft Water Depth in Channel Based On Design Peak Flow Design Peak Flow Qo = 1.94 1.94 cfs Water Depth d = 0.19 0.19 feet Inlet Design Information (Input) Type of Inlet Inlet Type = Angle of Inclined Grate (must be <= 30 degrees) θ = 0.00 degrees Width of Grate W = 1.00 feet Length of Grate L = 1.00 feet Open Area Ratio ARATIO = 0.70 Height of Inclined Grate HB = 0.00 feet Clogging Factor Cf = 0.50 Grate Discharge Coefficient Cd = N/A Orifice Coefficient Co = 0.64 Weir Coefficient Cw = 2.05 MINOR MAJOR Water Depth at Inlet (for depressed inlets, 1 foot is added for depression) d = 0.19 0.19 Total Inlet Interception Capacity (assumes clogged condition) Qa = 0.52 0.52 cfs WARNING: Inlet Capacity less than Q Peak for Minor and Major Storms Bypassed Flow, Qb = 1.42 1.42 cfs Capture Percentage = Qa/Qo = C% 27 27 % Warning 01: Sideslope steepness exceeds USDCM Volume I recommendation. Warning 02: Depth (d) exceeds USDCM Volume I recommendation. Warning 04: Froude No. exceeds USDCM Volume I recommendation. User-Defined AREA INLET IN A TRAPEZOIDAL GRASS-LINED CHANNEL CSU MEDICAL CENTER C1C Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' Choose One: Sandy Non-Sandy 2487C - UD-Inlet_v3.14- AREA DRAIN C1C.xlsm, Area Inlet 11/10/2015, 9:15 AM Grass Type Limiting Manning's n A 0.06 B 0.04 C 0.033 D 0.03 E 0.024 Analysis of Trapezoidal Grass-Lined Channel Using SCS Method NRCS Vegetal Retardance (A, B, C, D, or E) A, B, C, D or E Manning's n (Leave cell D16 blank to manually enter an n value) n = 0.030 Channel Invert Slope SO = 0.0200 ft/ft Bottom Width B = 5.00 ft Warning 01 Left Side Slope Z1 = 0.19 ft/ft Warning 01 Right Side Slope Z2 = 0.25 ft/ft Check one of the following soil types: Soil Type: Max. Velocity (VMAX) Max Froude No. (FMAX) Sandy 5.0 fps 0.50 Non-Sandy 7.0 fps 0.80 Minor Storm Major Storm Max. Allowable Top Width of Channel for Minor & Major Storm TMAX = 12.00 12.00 feet Max. Allowable Water Depth in Channel for Minor & Major Storm dMAX = 1.50 1.50 feet Allowable Channel Capacity Based On Channel Geometry Minor Storm Major Storm MINOR STORM Allowable Capacity is based on Depth Criterion Qallow = 55.79 55.79 cfs MAJOR STORM Allowable Capacity is based on Depth Criterion dallow = 1.50 1.50 ft Water Depth in Channel Based On Design Peak Flow Design Peak Flow Qo = 1.25 1.25 cfs Water Depth d = 0.14 0.14 feet Inlet Design Information (Input) Type of Inlet Inlet Type = Angle of Inclined Grate (must be <= 30 degrees) θ = 0.00 degrees Width of Grate W = 1.00 feet Length of Grate L = 1.00 feet Open Area Ratio ARATIO = 0.70 Height of Inclined Grate HB = 0.00 feet Clogging Factor Cf = 0.50 Grate Discharge Coefficient Cd = N/A Orifice Coefficient Co = 0.65 Weir Coefficient Cw = 2.05 MINOR MAJOR Water Depth at Inlet (for depressed inlets, 1 foot is added for depression) d = 0.14 0.14 Total Inlet Interception Capacity (assumes clogged condition) Qa = 0.31 0.31 cfs WARNING: Inlet Capacity less than Q Peak for Minor and Major Storms Bypassed Flow, Qb = 0.94 0.94 cfs Capture Percentage = Qa/Qo = C% 25 25 % Warning 01: Sideslope steepness exceeds USDCM Volume I recommendation. Warning 02: Depth (d) exceeds USDCM Volume I recommendation. Warning 04: Froude No. exceeds USDCM Volume I recommendation. User-Defined AREA INLET IN A TRAPEZOIDAL GRASS-LINED CHANNEL CSU MEDICAL CENTER C1D Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' Choose One: Sandy Non-Sandy 2487C - UD-Inlet_v3.14- AREA DRAIN C1D.xlsm, Area Inlet 11/10/2015, 9:16 AM Project: Inlet ID: Gutter Geometry (Enter data in the blue cells) Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.002 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020) nBACK = 0.016 Height of Curb at Gutter Flow Line HCURB = 6.00 inches Distance from Curb Face to Street Crown TCROWN = 20.0 ft Gutter Width W = 1.50 ft Street Transverse Slope SX = 0.020 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft) SW = 0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO = 0.010 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020) nSTREET = 0.016 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX = 18.0 18.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 6.0 6.0 inches Allow Flow Depth at Street Crown (leave blank for no) check = yes MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow = 12.1 12.1 cfs Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) CSU MEDICAL CENTER C2B (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' 2487C - UD-Inlet_v3.14- TYPE R 5FT GRADE C2B.xlsm, Q-Allow 11/10/2015, 9:20 AM Project: Inlet ID: Design Information (Input) MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') aLOCAL = 3.0 3.0 inches Total Number of Units in the Inlet (Grate or Curb Opening) No = 1 1 Length of a Single Unit Inlet (Grate or Curb Opening) Lo = 5.00 5.00 ft Width of a Unit Grate (cannot be greater than W from Q-Allow) Wo = N/A N/A ft Clogging Factor for a Single Unit Grate (typical min. value = 0.5) Cf -G = N/A N/A Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1) Cf -C = 0.10 0.10 Summary MINOR MAJOR Total Inlet Interception Capacity Q = 2.00 2.00 cfs Total Inlet Carry-Over Flow (flow bypassing inlet) Qb = 0.7 0.7 cfs Capture Percentage = Qa /Qo = C% = 75 75 % INLET ON A CONTINUOUS GRADE CSU MEDICAL CENTER C2B CDOT Type R Curb Opening 2487C - UD-Inlet_v3.14- TYPE R 5FT GRADE C2B.xlsm, Inlet On Grade 11/10/2015, 9:21 AM Project = Inlet ID = Design Information (Input) MINOR MAJOR Type of Inlet Inlet Type = Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') alocal = 3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening) No = 1 1 Water Depth at Flowline (outside of local depression) Ponding Depth = 5.5 5.5 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) = N/A N/A feet Width of a Unit Grate Wo = N/A N/A feet Area Opening Ratio for a Grate (typical values 0.15-0.90) Aratio = N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70) Cf (G) = N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60) Cw (G) = N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80) Co (G) = N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) = 5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert = 6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat = 6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5) Theta = 63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet) Wp = 1.50 1.50 feet Clogging Factor for a Single Curb Opening (typical value 0.10) Cf (C) = 0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7) Cw (C) = 3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70) Co (C) = 0.67 0.67 MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition) Q a = 4.7 4.7 cfs Inlet Capacity IS GOOD for Minor and Major Storms (>Q PEAK) Q PEAK REQUIRED = 1.3 3.7 cfs INLET IN A SUMP OR SAG LOCATION CSU MEDICAL CENTER C1A, C2A, C4A, C5A, C1B CDOT Type R Curb Opening H-Vert H-Curb W Lo (C) Lo (G) Wo WP Override Depths 2487C - UD-Inlet_v3.14- TYPE R 5FT SUMP.xlsm, Inlet In Sump 11/10/2015, 9:19 AM Project = Inlet ID = Design Information (Input) MINOR MAJOR Type of Inlet Inlet Type = Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') alocal = 3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening) No = 1 1 Water Depth at Flowline (outside of local depression) Ponding Depth = 6.0 6.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) = N/A N/A feet Width of a Unit Grate Wo = N/A N/A feet Area Opening Ratio for a Grate (typical values 0.15-0.90) Aratio = N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70) Cf (G) = N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60) Cw (G) = N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80) Co (G) = N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) = 10.00 10.00 feet Height of Vertical Curb Opening in Inches Hvert = 6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat = 6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5) Theta = 63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet) Wp = 1.50 1.50 feet Clogging Factor for a Single Curb Opening (typical value 0.10) Cf (C) = 0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7) Cw (C) = 3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70) Co (C) = 0.67 0.67 MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition) Q a = 9.2 9.2 cfs Inlet Capacity IS GOOD for Minor and Major Storms (>Q PEAK) Q PEAK REQUIRED = 8.9 8.9 cfs INLET IN A SUMP OR SAG LOCATION CSU MEDICAL CENTER C3A CDOT Type R Curb Opening H-Vert H-Curb W Lo (C) Lo (G) Wo WP Override Depths 2487C - UD-Inlet_v3.14- TYPE R 10FT SUMP C3A.xlsm, Inlet In Sump 11/10/2015, 9:18 AM APPENDIX C – FIGURE 1. Developed Drainage Map TOTAL SITE 66,257 65,408 46,424 0 0 70,220 248,309 5.70 69.9% Copy of 2487c - Rational Calculations LAT.xlsx Developed Imperv Calcs Page 1 of 1