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HomeMy WebLinkAboutTHE ODELL WINE PROJECT - MJA190002 - SUBMITTAL DOCUMENTS - ROUND 2 - DRAINAGE REPORTFinal Drainage Report Odell Wine Project Fort Collins, Colorado October 16, 2019 Prepared for: Brenden McGivney Odell Investments, LLC 800 E. Lincoln Avenue Fort Collins, Colorado 80525 Prepared by: 301 N. Howes Street Suite 100 Fort Collins, Colorado 80521 Phone: 970.221.4158 www.northernengineering.com Project Number: 100-020 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 necessary, we recommend double-sided printing. October 16, 2019 City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, CO 80521 RE: Preliminary Drainage Report for Odell Wine Project Dear Staff: Northern Engineering is pleased to submit this Final Drainage Report for your review. This report accompanies the combined Major Amendment submittal for the proposed Odell Wine Project. This report has been prepared in accordance with the Fort Collins Stormwater Criteria Manual (FCSCM) and serves to document the stormwater impacts associated with the proposed The Odell Wine Project. We understand that review by the City of Fort Collins 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. Frederick S. Wegert, PE Project Engineer Drainage Report October 16, 2019 Odell Investments Table of Contents Table of Contents I. General Location and Description ........................................................................ 1 II. Drainage Basins and Sub-Basins .......................................................................... 4 III. Drainage Design Criteria ..................................................................................... 4 IV. Drainage Facility Design ..................................................................................... 7 V. Conclusions ....................................................................................................... 13 VI. References ......................................................................................................... 14 Tables and Figures Figure 1: Vicinity Map ...................................................................................... 1 Figure 2: Aerial Photography .......................................................................... 2 Figure 3: FEMA Firmette (FEMA National Flood Hazard Level website) ........ 3 Table 1: Basin A1 Drainage Characteristics .................................................... 8 Table 2: As-built Volumes for 800 E. Lincoln Ave. .......................................... 9 Table 3: Basin A2 Drainage Characteristics .................................................... 9 Table 4: Basin B Drainage Characteristics .................................................... 10 Table 5: Basin C Drainage Characteristics.................................................... 10 Table 6: Basin OS1 Drainage Characteristics ............................................... 11 Table 7: Basin OS2 Drainage Characteristics ............................................... 11 Table 8: Drainage Characteristics for Basins A & B ...................................... 12 Table 9: Runon Ratio for Permeable Pavers ................................................. 12 Appendices Appendix A – Hydrologic Computations Appendix B – Hydraulic Computations Appendix C – Water Quality/Lid Design Computations Appendix D – Erosion Control Report Appendix E – USDA Soils Report Appendix F – Historical Drainage Certifications Exceprts Appendix G – FEMA Firmette Map Pocket DR1 – Drainage Exhibit Drainage Report October 16, 2019 Odell Investments Page 1 of 16 I. General Location and Description A. Location 1. Vicinity Map 2. The Odell Wine Project site is located in the northeast quarter of Section 12, 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 (refer to Figure 1) is bordered to the north by vacant land with evidence of industrial use; to the south by Lincoln Avenue; to the east by industrial warehouse, and to the west by Odell Brewery. The project is an expansion of the Odell Brewery operations. Figure 1: Vicinity Map Drainage Report October 16, 2019 Odell Investments Page 2 of 16 4. There are no major drainageways within the project site. B. Description of Property 1. The Odell Wine Project is comprised of ±0.86 acres. 2. The site is currently composed of a steel frame industrial building and hardscape (asphalt and concrete) parking lot with concrete and gravel industrial access. The building is currently used for Odell’s barrel storage. 3. The existing groundcover consists of grasses, concrete and gravel. The existing on-site runoff generally drains from the north-to-south across flat grades (e.g., <3.00%) towards Lincoln Avenue. From there, the drainage continues into the City of Fort Collins storm sewer system and on to the Cache La Poudre River. 4. According to the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Soil Survey website: (http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx), the site consists primarily of Loveland clay loam (Hydrologic Soil Group C) and Table Mountain Loam (Hydrologic Soil Group B). The drainage calculations assume a Hydrologic Soil Group of C for the entire site. 5. There are no major drainageway within or adjacent to the project site. Figure 2: Aerial Photography Drainage Report October 16, 2019 Odell Investments Page 3 of 16 6. The project consists of renovating the existing building and parking lot into a wine and beer tasting room as part of Odell Brewery. Other proposed improvements include: an outdoor patio, permeable pavers, new sidewalks and new landscaping. 7. The proposed land use is industrial. This is a permitted use in the Industrial District (I). C. Floodplain 1. The subject property is located in FEMA regulatory floodplain. In particular, the project site is located within FEMA designated “Area with Reduced Flood Risk Due to Levee (Zone X)” per the FEMA National Flood Hazard Level website. Figure 3: FEMA Firmette (FEMA National Flood Hazard Level website) Drainage Report October 16, 2019 Odell Investments Page 4 of 16 II. Drainage Basins and Sub-Basins A. Major Basin Description The Odell Wine Project is located within the City of Fort Collins Dry Creek major drainage basin. Specifically, the project site is situated in the southwestern corner of this major drainage basin. The Dry Creek major drainage basin generally drains from northwest to southeast. Runoff from the major drainage basin drains to Dry Creek and ultimately to the Cache La Poudre River. B. Sub-Basin Description 1. The outfall for the project site is an existing 24-inch storm sewer in Lincoln Street. 2. The existing subject site can be defined with two (4) onsite subbasins and two (2) offsite subbasin. 3. The existing site runoff generally drains from north-to-south and into the East Pond constructed as part of the Odell Brewery drainage improvements. 4. The project site receives offsite runoff from a hillside along the north property line. III. Drainage Design Criteria A. Optional Provisions There are no optional provisions outside of the FCSCM proposed with Odell Wine Project. However, the constructed conditions from 800 E. Lincoln Avenue (Odell Brewery), as documented in the drainage certification and addendum, prepared in February 2014 by Northern Engineering, does influence the drainage design for the Odell Wine Project. B. Stormwater Management Strategy The overall stormwater management strategy employed with the Odell Wine 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. The first consideration taken in trying to reduce the stormwater impacts of this development is the site selection itself. By choosing an already developed site with public storm sewer currently in place, the burden is significantly less than developing a vacant parcel absent of any infrastructure. Drainage Report October 16, 2019 Odell Investments Page 5 of 16 The Odell Wine Project aims to reduce runoff peaks, volumes and pollutant loads from frequently occurring storm events (i.e., water quality (i.e., 80th percentile) and 2-year storm events) by implementing Low Impact Development (LID) strategies. Wherever practical, runoff will be routed across landscaped areas or permeable pavers. These LID practices reduce the overall amount of impervious area, while at the same time Minimizing Directly Connected Impervious Areas (MDCIA). The combined LID/MDCIA techniques will be implemented, where practical, throughout the development, thereby slowing runoff and increasing opportunities for infiltration. Step 2 – Implement BMPs that Provide a Water Quality Capture Volume (WQCV) with Slow Release. The efforts taken in Step 1 will help to minimize excess runoff from frequently occurring storm events; however, urban development of this intensity will still have stormwater runoff leaving the site. The primary water quality treatment will occur in the permeable pavers located at the east end of the project. Step 3 – Stabilize Drainageways. No changes to the onsite and surrounding drainage systems are proposed with this project. While this step may not seem applicable to The Odell Wine Project, the proposed project indirectly helps achieve stabilized drainageways, nonetheless. Once again, site selection has a positive effect on stream stabilization. By developing an infill site with existing stormwater infrastructure, combined with LID and MDCIA strategies, the likelihood of bed and bank erosion is 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. The primary source of LID and permeant BMP’s for the Odell Wine Project are the permeable pavers located within the parking area. This will reduce runoff and implement water quality for what stormwater that includes a significant concentration of oils, grease, and suspended solids. Additional sources of BMP’s will include landscaping strips and the East Pond constructed as part of 800 E. Lincoln Avenue drainage improvements. C. Development Criteria Reference and Constraints 1. The subject property is not part of any Overall Development Plan (ODP) drainage study or similar “development/project” drainage master plan. However, the East Pond of 800 E. Lincoln Avenue was designed with the intention to provide stormwater detention for 824 E. Lincoln Avenue for an interim condition. According to the drainage certifications for the East Pond, the East Pond was constructed with insufficient volume (see Section IV.A.4 Sub- Basin A below for more detail). Drainage Report October 16, 2019 Odell Investments Page 6 of 16 2. The site plan is constrained on the south side by a public street and by existing development along the east and west sides. A large hill constrains the project on the north side. D. Hydrological Criteria 1. The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in Figure 3.4-1 of the FCSCM, serve as the source for all hydrologic computations associated with Odell Wine Project. Tabulated data contained in Table 3.4-1 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 Federal Aviation Administration (FAA) procedure has been utilized for detention storage calculations. 4. Two separate design storms have been utilized to address distinct drainage scenarios. The first event analyzed is the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The second event considered is the “Major Storm,” which has a 100-year recurrence interval. E. Hydraulic Criteria 1. The drainage facilities proposed with Odell Wine 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. 2. As stated in Section I.C.1, above, the subject property is located within FEMA Floodplain Zone X with reduced flood risk due to a levee. F. Floodplain Regulations Compliance 1. The entire the project is located within FEMA Floodplain Zone X with reduced flood risk due to a levee. G. Modifications of Criteria No formal modifications are requested at this time. H. Conformance with Water Quality Treatment Criteria City Code requires that 100% of runoff from a project site receive some sort of water quality treatment. This project proposes to provide water quality treatment through the use of permeable pavers located along the east of the project under the drive aisle and parking lot. These pavers are considered a LID treatment method. Due to the Drainage Report October 16, 2019 Odell Investments Page 7 of 16 physical constraints associated with an infill project of this nature and the prohibition of providing water quality facilities within the public right-of-way, there are some small, narrow areas around the perimeter of the project that cannot be captured. The uncaptured areas tend to be landscaping areas along Lincoln Avenue and existing concrete and gravel industrial yard areas along the north area of the project. The concrete and gravel industrial areas along the north property line will maintain the existing drainage patterns towards the East Pond located on 800 E. Lincoln Avenue (Odell Brewery). I. Conformance with Low Impact Development (LID) The project site will conform with the requirement to treat a minimum of 50% of new impervious area project site using permeable pavers. Please see Appendix C for LID design information, table, and exhibit(s). As shown in the LID table provided in the appendix, 79.9% of the proposed site impervious area will receive LID treatment, which exceeds the minimum required. J. Sizing of LID Facilities 1. The permeable pavers were sized by first determining the required water quality capture volume (WQCV) and detention volume for Sub-Basins A-1, A-2, and B. A 12-hour drain time was used for the WQCV calculation. 2. Once the total volume was identified, the depth of subbase was determined to achieve this volume was calculated. A 30% void ratio was assumed per the FCSM. IV. Drainage Facility Design A. General Concept 1. The main objective of Odell Wine Project drainage design is to maintain existing drainage patterns, while not adversely impacting adjacent properties. As part of this objective, the Odell Wine Project is to reduce the impact from this site on the East Pond on 800 E. Lincoln Avenue. 2. The hillside along the north property line is a significant source of offsite drainage impacting this site. See Sub-Basin OS below for further discussion 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. Drainage Report October 16, 2019 Odell Investments Page 8 of 16 4. Drainage for the project site has been analyzed using three (3) drainage sub- basins, designated as Sub-Basins A, B, and OS. The drainage patterns anticipated for the basins are further described below. Sub-Basin A1 The existing and proposed drainage patterns for Sub-Basin A-1 remain unchanged. Sub-Basin A1 consists of the southern half of the project west of an existing steel building. Roof drainage from the western half of the existing steel building discharges, via downspouts, into an existing concrete and asphalt driveway and industrial yard. Stormwater will then sheet flow across the concrete, into the permeable pavers, and ultimately into the existing storm sewer along the west property boundary. The proposed improvements to Sub-Basin A1 include replacing a portion of the asphalt and concrete driveway with permeable pavers and landscaped areas. The pavers are sized to provide the required water quality and detention volume for the improvements to 824 E. Lincoln Avenue that cannot be achieved from the East Pond on 800 E. Lincoln Avenue. According to the Final Drainage Certification Memorandum for 2013 Odell Brew House Expansion, by Northern Engineering dated February 8, 2014, the shortage is due to the volume burden from 824 E. Lincoln Avenue. Table 1 is a summary of the basin area, impervious area, percent impervious, and calculated flowrates for Sub-Basin A1. Basin A1 Drainage Characteristics Existing Proposed Basin Area (sq. ft.) 11,607 18,996 Impervious Area (sq. ft.) 7,705 11,443 Percent Impervious 73% 65% 2-Year Flowrate (cfs) 0.46 0.63 10-Year Flowrate (cfs) 0.79 1.08 100-Year Flowrate (cfs) 2.41 3.13 Table 1: Basin A1 Drainage Characteristics Sub-Basin A2 The existing and proposed drainage patterns for Sub-Basin A-2 remain unchanged. Sub-Basin A2 consists of the northern half of the project west of an existing steel building. Roof drainage from the western half of the existing steel building discharges, via downspouts, into an existing concrete and asphalt driveway and industrial yard. Stormwater will then sheet flow across the concrete, onto a poorly vegetated landscaping strip, and ultimately into the East Pond for Odell Brewery (800 E. Lincoln Avenue). A concrete valley pan midway on the site and a swale along the west property boundary helps to collect and direct drainage towards the East Pond. Drainage Report October 16, 2019 Odell Investments Page 9 of 16 The East Pond was originally designed for the 100-year storm event from both 800 and 824 E. Lincoln Avenue. However, due to construction revisions and the relocation of several mature trees, the East Pond was constructed with less than the design volume (Addendum to Final Drainage Certification Memorandum for 2013 Odell Brew House Expansion by Northern Engineering dated February 18, 2014). The combined as-constructed volumes of the permeable pavers and the East Pond, per the Addendum to Final Drainage Certification Memorandum for 2013 Odell Brew House Expansion is documented in Table 2 below. As-built Volumes for 800 E. Lincoln Ave. Required Volume 800 E. Lincoln Ave. 11,118 ft3 824 E. Lincoln Ave. 2,554 ft3 Total 13,672 ft3 As-built Volume Permeable Pavers 2,261 ft3 East Pond 9,620 ft3 Total 11,881 ft3 All volumes from Addendum to Final Drainage Certification Memorandum for 2013 Odell Brew House Expansion by Northern Engineering dated 02/18/2014. Table 2: As-built Volumes for 800 E. Lincoln Ave. The proposed improvements to Sub-Basin A2 include expanding the concrete driveway to meet Poudre Fire Authority emergency access requirements. Because the permeable pavers within Sub-Basin A1 was sized to provide the total site’s LID and water quality requirements, Sub-Basin A2 is not required to provide any LID treatment. However, the East Detention Pond on 800 E. Lincoln Avenue will provide both stormwater detention and water quality for the proposed improvements within Sub-Basin A2. Table 3 is a summary of the basin area, impervious area, percent impervious, and calculated flowrates for Sub- Basin A2. Basin A2 Drainage Characteristics Existing Proposed Basin Area (sq. ft.) 11,607 1,188 Impervious Area (sq. ft.) 7,705 11,745 Percent Impervious 73% 76% 2-Year Flowrate (cfs) 0.46 0.68 10-Year Flowrate (cfs) 0.79 1.16 100-Year Flowrate (cfs) 2.41 3.49 Table 3: Basin A2 Drainage Characteristics Sub-Basin B The existing drainage pattern for Sub-Basin B with drainage from the existing building’s southern downspouts, across an existing concrete patio with Drainage Report October 16, 2019 Odell Investments Page 10 of 16 landscaping islands, and into a grass sump located between the concrete patios and the existing sidewalk in Lincoln Avenue. A storm inlet drains the sump into the 24” storm sewer along Lincoln Avenue. The proposed improvements will follow the same drainage patterns as the existing, but a small landscaping berm will intercept flows from the downspouts and the concrete patio and redirect it into the permeable pavers in Sub-Basin A. Table 4 is a summary of the basin area, impervious area, percent impervious, and calculated flowrates for Sub-Basin B. Basin B Drainage Characteristics Existing Proposed Basin Area (sq. ft.) 14,121 1,188 Impervious Area (sq. ft.) 1,734 0 Percent Impervious 59% 20% 2-Year Flowrate (cfs) 0.51 0.02 10-Year Flowrate (cfs) 0.88 0.03 100-Year Flowrate (cfs) 2.39 0.07 Table 4: Basin B Drainage Characteristics Sub-Basin C The existing and proposed drainage patterns for Sub-Basin C will remain unchanged. Sub-Basin C consists of everything east of the existing steel building that drains towards the east property line. Roof drainage from the eastern half of the existing steel building discharges, via downspouts, into an existing gravel and concrete industrial yard. Stormwater will then sheet flow across the industrial yard towards the east property boundary. The proposed improvements will follow the same drainage patterns as the existing, but the gravel and concrete within the industrial yard will be replaced with landscaping. A 20’ wide strip of gravel will remain to provide emergency access loop the rear and east side of the building. Table 5 is a summary of the basin area, impervious area, percent impervious, and calculated flowrates for Sub-Basin C. Basin C Drainage Characteristics Existing Proposed Basin Area (sq. ft.) 8,294 8,294 Impervious Area (sq. ft.) 5,301 2,581 Percent Impervious 68% 48% 2-Year Flowrate (cfs) 0.32 0.21 10-Year Flowrate (cfs) 0.54 0.35 100-Year Flowrate (cfs) 1.50 0.96 Table 5: Basin C Drainage Characteristics Drainage Report October 16, 2019 Odell Investments Page 11 of 16 Sub-Basin OS1 and OS2 The existing and proposed drainage patterns for Sub-Basins OS1 and OS2 will remain unchanged. Sub-Basins OS1 and OS2 consists of the hillside to the north of the property. Sub-Basins OS1 and OS2 drains directly onto the gravel industrial yard between the building and the northern property line. Sub-Basin OS1 drains towards the northeastern corner of the site, into a swale along the western property line, and ultimately into the East Pond. A 15” HDPE storm sewer was installed along the western property line, bypassing the East Pond, and ultimately into the 24” storm sewer along Lincoln Avenue. However, no inlet was installed that would allow drainage from Sub-Basin OS to bypass the East Pond. Sub-Basin OS-2 drains into Basin C and ultimately towards the east property line. A concrete private access at the northwestern corner, between 800 and 824 E. Lincoln Avenue, of the site is the only proposed improvement within Sub-Basin OS. A swale and inlet will be constructed along the north property line to intercept Sub-Basin OS1 and redirect it into the existing 15” HDPE storm sewer. Table 6 is a summary of the basin area, impervious area, percent impervious, and calculated flowrates for Sub-Basin OS1. Basin OS1 Drainage Characteristics Existing Proposed Basin Area (sq. ft.) 7,595 7,595 Impervious Area (sq. ft.) 0 693 Percent Impervious 20% 27% 2-Year Flowrate (cfs) 0.08 0.11 10-Year Flowrate (cfs) 0.14 0.19 100-Year Flowrate (cfs) 0.37 0.50 Table 6: Basin OS1 Drainage Characteristics Table 7 is a summary of the basin area, impervious area, percent impervious, and calculated flowrates for Sub-Basin OS2. Basin OS2 Drainage Characteristics Existing Proposed Basin Area (sq. ft.) 1,519 1,519 Impervious Area (sq. ft.) 0 0 Percent Impervious 20% 20% 2-Year Flowrate (cfs) 0.02 0.02 10-Year Flowrate (cfs) 0.03 0.03 100-Year Flowrate (cfs) 0.08 0.08 Table 7: Basin OS2 Drainage Characteristics Drainage Report October 16, 2019 Odell Investments Page 12 of 16 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 existing impervious area was considered in determining allowable release from the property. The 2-yr historic release rate for the project is based on a hydrologic analysis of the site’s existing conditions (see Table 5 below) of the combined Sub-Basins A and B. The historic 2-yr release rate is 1.33 cfs and requires a detention of 4,885 cu. ft and a depth of paver sub-base of 3.0 ft. Basin A-B Drainage Characteristics Existing Proposed Basin Area (sq. ft.) 37,335 37,344 Impervious Area (sq. ft.) 22,397 23,188 Percent Impervious 68% 69% 2-Year Flowrate (cfs) 1.33 1.30 10-Year Flowrate (cfs) 2.28 2.23 100-Year Flowrate (cfs) 6.74 6.49 Table 8: Drainage Characteristics for Basins A & B 2. The FAA method was used to size the on-site detention volume. C. Sizing of LID Facilities Permeable Pavers The permeable pavers were sized by first determining the required water quality capture volume (WQCV) and detention volume for Sub-Basins A-1, A-2 and B. A 12-hour drain time was used for the WQCV calculation. Once the total volume was identified, the depth of subbase was determined to achieve this volume was calculated. A 30% void ratio was assumed per the FCSM. The runon ratio of impervious area to permeable pavers is 1.75:1 (see Table 9). Runon Ratio for Permeable Pavers Area of Asphalt/Concrete 4,877 ft2 Area of Rooftop 2,891 ft2 Area of Gravel 1,842 ft2 Total Impervious Area 9,610 ft2 Area of Pavers 5,507 ft2 Runon Ratio 1.75 Table 9: Runon Ratio for Permeable Pavers Drainage Report October 16, 2019 Odell Investments Page 13 of 16 V. Conclusions A. Compliance with Standards 1. The design elements comply without variation and meet all LID requirements. 2. The drainage design proposed with Odell Wine Project complies with the City of Fort Collins Master Drainage Plan for the Dry Creek Basin. 3. As stated in Section I.C.1, above, the subject property is located within Floodplain Zone X with reduced flood risk due to a levee. 4. The drainage plan and stormwater management measures proposed with Odell Wine Project are compliant with all applicable State and Federal regulations governing stormwater discharge. B. Drainage Concept 1. The Odell Wine Project will not impact the Master Drainage Plan recommendations for the Dry Creek major drainage basin. 2. The Odell Wine Project will reduce the burden on the East Pond for 800 E. Lincoln Street. Upon completion of the permeable pavers for Odell Wine Project, the East Pond for 800 E. Lincoln Street will be in compliance with City of Fort Collins stormwater regulations. 3. The Odell Wine Project will provide LID, water quality, and detention for the proposed impervious areas. The existing pervious areas not modified by the Odell Wine Project will flow into the East Pond on 800 E. Lincoln Street. This will still provide some water quality and LID treatment for the site. The hydrologic capacity of the East Pond will not be impacted due to the additional permeable pavers proposed by the Odell Wine Project. Drainage Report October 16, 2019 Odell Investments Page 14 of 16 VI. References 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. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No. 159, 2018, and referenced in Section 26-500 of the City of Fort Collins Municipal Code. Final Drainage Certification Memorandum for 2013 Odell Brew House Expansion, Northern Engineering, Fort Collins, Colorado, February 3, 2014. Addendum to Final Drainage Certification Memorandum for 2013 Odell Brew House Expansion, Northern Engineering, Fort Collins, Colorado, February 18, 2014. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation Service, United States Department of Agriculture. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008. Appendix A Hydrologic Computations Runoff Coefficient1 Percentage Impervious1 Project: 0.95 95% Calculations By: 0.95 95% Date: October 16,2019 0.50 50% 0.50 50% 0.20 20% 2-year Cf = 1.00 10-year Cf = 1.00 Basin ID Basin Area (sq. ft.) Basin Area (ac.) Asphalt, Concrete (ac.) Rooftop (ac.) Gravel (ac.) Pavers (ac.) Lawns, Clayey Soil, Flat Slope < 2% (ac.) 2-year Composite Runoff Coefficient 10-year Composite Runoff Coefficient 100-year Composite Runoff Coefficient Composite % Imperv. HA 23,214 0.53 0.14 0.13 0.16 0.00 0.24 0.73 0.73 0.91 73% HB 14,121 0.32 0.12 0.04 0.01 0.00 0.20 0.59 0.59 0.74 59% HOS 7,595 0.17 0.00 0.00 0.00 0.00 0.17 0.20 0.20 0.25 20% A-B 37,335 0.86 0.26 0.17 0.16 0.00 0.43 0.68 0.68 0.84 68% 1) Runoff coefficients are taken from the Fort Collins Stormwater Criteria Manaual, Table 3.2.1 and Table 3.2.2. 100-year Cf = 1.25 Combined Basins HISTORIC COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS Odell Wine F. Wegert Character of Surface: USDA SOIL TYPE: C Asphalt, Concrete Rooftop Gravel Pavers Lawns, Clayey Soil, Flat Slope < 2% Composite Runoff Coefficient with Adjustment 10/15/2019 1:50 PM P:\100-020\Drainage\Hydrology\100-020_FC Rational_Historic.xlsx\Composite C Project: Odell Wine Calculations By: Date: Length, L (ft) Up Stream Elevation Down Stream Elevation Slope, S (%) T i 2-yr (min) T i 10-yr (min) T i 100-yr (min) Length, L (ft) Up Stream Elevation Down Stream Elevation Slope, S (%) Velocity, V (ft/s) T t (min) Length, L (ft) Up Stream Elevation Down Stream Elevation Slope, S (%) Velocity, V (ft/s) T t (min) 2-yr (min) 10-yr (min) 100-yr (min) C2 C10 C100 i2 (in/hr) i10 (in/hr) i100 (in/hr) Q2 (cfs) Q10 (cfs) Q100 (cfs) ha HA 0.53 8.24 8.24 5.04 0.73 0.73 0.91 2.40 4.10 9.95 0.93 1.59 4.82 hb HB 0.32 6.04 6.04 5.00 0.59 0.59 0.74 2.67 4.56 9.95 0.51 0.88 2.39 hos HOS 0.17 8.54 8.54 8.14 0.20 0.20 0.25 2.35 4.02 8.38 0.08 0.14 0.37 a-b A-B 0.86 9.13 9.13 6.15 0.68 0.68 0.84 2.30 3.93 9.31 1.33 2.28 6.74 Combined Basins HISTORIC RUNOFF COMPUTATIONS Rational Method Equation: Rainfall Intensity: Rainfall Intensity taken from the Fort Collins Stormwater Criteria Manual (FCSCM), Tables RA-7 and RA-8 Design Point Basin(s) Area, A (acres) Tc Runoff Coefficient Intensity Flow Project: Calculations By: Date: Odell Wine F. Wegert October 16,2019 Q = C f ( C )( i )( A ) 10/15/2019 1:52 PM P:\100-020\Drainage\Hydrology\100-020_FC Rational_Historic.xlsx\Runoff Runoff Coefficient1 Percentage Impervious1 Project: 0.95 95% Calculations By: 0.95 95% Date: October 16,2019 0.50 50% 0.50 50% 0.20 20% 2-year Cf = 1.00 10-year Cf = 1.00 Basin ID Basin Area (sq. ft.) Basin Area (ac.) Asphalt, Concrete (ac.) Rooftop (ac.) Gravel (ac.) Pavers (ac.) Lawns, Clayey Soil, Flat Slope < 2% (ac.) 2-year Composite Runoff Coefficient 10-year Composite Runoff Coefficient 100-year Composite Runoff Coefficient Composite % Imperv. A-1 18,996 0.44 0.11 0.07 0.04 0.13 0.16 0.65 0.65 0.82 65% A-2 17,161 0.39 0.15 0.11 0.03 0.00 0.21 0.76 0.76 0.95 76% B 1,188 0.03 0.00 0.00 0.00 0.00 0.03 0.20 0.20 0.25 20% C 8,294 0.19 0.00 0.05 0.01 0.00 0.17 0.48 0.48 0.60 48% OS-1 7,595 0.17 0.02 0.00 0.00 0.00 0.16 0.27 0.27 0.34 27% OS-2 1,519 0.03 0.00 0.00 0.00 0.00 0.03 0.20 0.20 0.25 20% A-B 37,344 0.86 0.26 0.17 0.07 0.13 0.40 0.69 0.69 0.86 69% A-B-OS1 44,939 1.03 0.28 0.17 0.07 0.13 0.56 0.62 0.62 0.77 62% C-OS2 9,813 0.23 0.00 0.05 0.01 0.00 0.21 0.44 0.44 0.55 44% 1) Runoff coefficients are taken from the Fort Collins Stormwater Criteria Manaual, Table 3.2.1 and Table 3.2.2. 100-year Cf = 1.25 Combined Basins PROPOSED COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS Odell Wine F. Wegert Character of Surface: USDA SOIL TYPE: C Lawns, Clayey Soil, Flat Slope < 2% Pavers Gravel Rooftop Project: Odell Wine Calculations By: Date: Length, L (ft) Up Stream Elevation Down Stream Elevation Slope, S (%) T i 2-yr (min) T i 10-yr (min) T i 100-yr (min) Length, L (ft) Up Stream Elevation Down Stream Elevation Slope, S (%) Velocity, V (ft/s) T t (min) Length, L (ft) Up Stream Elevation Down Stream Elevation Slope, S (%) Velocity, V (ft/s) T t (min) 2-yr (min) 10-yr (min) 100-yr (min) C2 C10 C100 i2 (in/hr) i10 (in/hr) i100 (in/hr) Q2 (cfs) Q10 (cfs) Q100 (cfs) a-1 A-1 0.44 10.09 10.09 7.31 0.65 0.65 0.82 2.21 3.78 8.80 0.63 1.08 3.13 a-2 A-2 0.39 9.84 9.84 6.17 0.76 0.76 0.95 2.26 3.86 9.31 0.68 1.16 3.49 b B 0.03 5.69 5.69 5.39 0.20 0.20 0.25 2.76 4.72 9.95 0.02 0.03 0.07 c C 0.19 9.63 9.63 8.45 0.48 0.48 0.60 2.26 3.86 8.38 0.21 0.35 0.96 os-1 OS-1 0.17 8.02 8.02 7.57 0.27 0.27 0.34 2.40 4.10 8.59 0.11 0.19 0.50 os-2 OS-2 0.03 6.23 6.23 5.89 0.20 0.20 0.25 2.67 4.56 9.63 0.02 0.03 0.08 a-1 A-B 0.86 10.33 10.33 7.01 0.69 0.69 0.86 2.21 3.78 8.80 1.30 2.23 6.49 a-1 A-B-OS1 1.03 10.27 10.27 9.23 0.62 0.62 0.77 2.21 3.78 8.03 1.41 2.41 6.39 c C-OS2 0.23 6.56 6.56 5.83 0.44 0.44 0.55 2.60 4.44 9.63 0.26 0.44 1.18 Calculations By: Date: Odell Wine F. Wegert October 16,2019 Combined Basins PROPOSED RUNOFF COMPUTATIONS Rational Method Equation: Rainfall Intensity: Rainfall Intensity taken from the Fort Collins Stormwater Criteria Manual (FCSCM), Tables RA-7 and RA-8 Design Point Basin(s) Area, A (acres) Tc Runoff Coefficient Intensity Flow Project: Q = C f ( C )( i )( A ) 10/15/2019 1:49 PM P:\100-020\Drainage\Hydrology\100-020_FC Rational_Developed.xlsx\Runoff X X X X X ROOFTOP CONCRETE ASPHALT GRAVEL SURFACE AREA (SF) % IMPERV. IMPERV. AREA (SF) 9,645 8,645 2,711 12,070 100% 100% 100% 50% 6,035 TOTALS 43,255 TOTAL= 27,036 ROOFTOP CONCRETE PAVERS GRAVEL SURFACE AREA (SF) % IMPERV. IMPERV. AREA (SF) 11,352 4,808 3,501 100% 100% 50% 50% TOTALS 43,255 TOTAL= 25,152 EXISTING PROPOSED 1,751 2,404 P:\100-020\DWG\DRNG\100-020_IMPV.DWG 824 E. LINCOLN AVENUE FORT COLLINS COLORADO Fort Collins: 301 N. Howes St., Ste. 100, 80521 Greeley: 820 8th Street, 80631 ENGINEER ING N O R T H E RN PHONE: 970.221.4158 www.northernengineering.com DESCRIPTION EXISTING VS. PROPOSED IMPERVIOUS AREA DRAWN BY F. WEGERT DATE OCTOBER 16, 2019 PROJECT 100-020 DR-A1 Appendix B Hydraulic Calculations Channel Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Tuesday, Oct 15 2019 15-in HDPE Storm Sewer Circular Diameter (ft) = 1.25 Invert Elev (ft) = 4942.40 Slope (%) = 0.25 N-Value = 0.012 Calculations Compute by: Known Q Known Q (cfs) = 0.59 Highlighted Depth (ft) = 0.35 Q (cfs) = 0.590 Area (sqft) = 0.28 Velocity (ft/s) = 2.08 Wetted Perim (ft) = 1.40 Crit Depth, Yc (ft) = 0.30 Top Width (ft) = 1.13 EGL (ft) = 0.42 0 1 2 3 Elev (ft) Section 4941.50 4942.00 4942.50 4943.00 4943.50 4944.00 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Tuesday, Oct 15 2019 15-in HDPE Storm Sewer with Flow from Pavers Circular Diameter (ft) = 1.25 Invert Elev (ft) = 4942.40 Slope (%) = 0.25 N-Value = 0.012 Calculations Compute by: Known Q Known Q (cfs) = 1.92 Highlighted Depth (ft) = 0.66 Q (cfs) = 1.920 Area (sqft) = 0.66 Velocity (ft/s) = 2.91 Wetted Perim (ft) = 2.04 Crit Depth, Yc (ft) = 0.55 Top Width (ft) = 1.25 EGL (ft) = 0.79 0 1 2 3 Elev (ft) Section 4941.50 4942.00 4942.50 4943.00 4943.50 4944.00 Reach (ft) Area Inlet Performance Curve: North Inlet (OS-1 & OS-2) Governing Equations: At low flow depths, the inlet will act like a weir governed by the following equation: * where P = 3.1416*Dia.of grate * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A) The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown. However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation will cross at a certain flow depth. The two curves can be found below: If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters: Type of Grate: Nyloplast 15" Dome Diameter of Grate (ft): 1.25 Open Area of Grate (ft2): 0.74 Rim Elevation (ft): 4945.750 Reduction Factor: 50% Depth vs. Flow: Depth Above Inlet (ft) Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs) 0.00 4945.75 0.00 0.00 0.00 0.12 4945.87 0.24 0.69 0.24 <-10-Year 0.20 4945.95 0.53 0.88 0.53 0.22 4945.97 0.59 0.92 0.59 <-100-Year 0.40 4946.15 1.49 1.25 1.25 0.60 4946.35 2.74 1.53 1.53 0.80 4946.55 4.21 1.77 1.77 1.00 4946.75 5.89 1.98 1.98 1.20 4946.95 7.74 2.17 2.17 1.40 4947.15 9.76 2.34 2.34 1.60 4947.35 11.92 2.50 2.50 100-Year Design Flow = 0.59 cfs 10-Year Design Flow = 0.22 cfs Q = 3 . 0 P H 1 . 5 Q = 0 . 67 A ( 2 gH ) 0 . 5 0.00 2.00 4.00 6.00 8.00 10.00 12.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Discharge (cfs) Stage (ft) Stage - Discharge Curves Weir Flow Orifice Flow Area Inlet Performance Curve: Permeable Pavers (North) Governing Equations: At low flow depths, the inlet will act like a weir governed by the following equation: * where P = 3.1416*Dia.of grate * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A) The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown. However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation will cross at a certain flow depth. The two curves can be found below: If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters: Type of Grate: Nyloplast 8" Grate Diameter of Grate (ft): 0.666666667 Open Area of Grate (ft2): 0.21 Rim Elevation (ft): 4945.940 Reduction Factor: 50% Depth vs. Flow: Depth Above Inlet (ft) Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs) 0.00 4945.94 0.00 0.00 0.00 0.20 4946.14 0.28 0.25 0.25 0.32 4946.26 0.57 0.32 0.32 <-2-Year 0.40 4946.34 0.79 0.36 0.36 0.60 4946.54 1.46 0.44 0.44 0.80 4946.74 2.25 0.50 0.50 0.92 4946.86 2.77 0.54 0.54 <-10-Year 1.00 4946.94 3.14 0.56 0.56 1.20 4947.14 4.13 0.62 0.62 1.40 4947.34 5.20 0.67 0.67 1.60 4947.54 6.36 0.71 0.71 10-Year Design Flow = 0.54 cfs 2-Year Design Flow = 0.32 cfs Q = 3 . 0 P H 1 . 5 Q = 0 . 67 A ( 2 gH ) 0 . 5 0.00 1.00 2.00 3.00 4.00 5.00 6.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Discharge (cfs) Stage (ft) Stage - Discharge Curves Weir Flow Orifice Flow Assumes permeable pavers are 100% clogged. Area Inlet Performance Curve: Permeable Pavers (South) Governing Equations: At low flow depths, the inlet will act like a weir governed by the following equation: * where P = 3.1416*Dia.of grate * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A) The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown. However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation will cross at a certain flow depth. The two curves can be found below: If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters: Type of Grate: Nyloplast 8" Grate Diameter of Grate (ft): 0.666666667 Open Area of Grate (ft2): 0.21 Rim Elevation (ft): 4944.930 Reduction Factor: 50% Depth vs. Flow: Depth Above Inlet (ft) Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs) 0.00 4944.93 0.00 0.00 0.00 0.20 4945.13 0.28 0.25 0.25 0.32 4945.25 0.57 0.32 0.32 <-2-Year 0.40 4945.33 0.79 0.36 0.36 0.60 4945.53 1.46 0.44 0.44 0.80 4945.73 2.25 0.50 0.50 0.92 4945.85 2.77 0.54 0.54 <-10-Year 1.00 4945.93 3.14 0.56 0.56 1.20 4946.13 4.13 0.62 0.62 1.40 4946.33 5.20 0.67 0.67 1.60 4946.53 6.36 0.71 0.71 10-Year Design Flow = 0.54 cfs 2-Year Design Flow = 0.32 cfs Q = 3 . 0 P H 1 . 5 Q = 0 . 67 A ( 2 gH ) 0 . 5 0.00 1.00 2.00 3.00 4.00 5.00 6.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Discharge (cfs) Stage (ft) Stage - Discharge Curves Weir Flow Orifice Flow Assumes permeable pavers are 100% clogged. Appendix C Water Quality/LID Design Computations Pond No : a 100-yr 0.86 5.20 min 4771 ft3 0.83 acres 0.11 ac-ft Max Release Rate = 1.33 cfs Time (min) Ft Collins 100-yr Intensity (in/hr) Inflow Volume (ft3) Outflow Adjustment Factor Qav (cfs) Outflow Volume (ft3) Storage Volume (ft3) 5 9.950 2131 1.00 1.33 399 1732 10 7.720 3306 0.76 1.01 606 2700 15 6.520 4189 0.67 0.90 806 3383 20 5.600 4797 0.63 0.84 1005 3791 25 4.980 5332 0.60 0.80 1205 4127 30 4.520 5807 0.59 0.78 1404 4403 35 4.080 6116 0.57 0.76 1604 4512 40 3.740 6407 0.57 0.75 1803 4604 45 3.460 6668 0.56 0.74 2003 4665 50 3.230 6917 0.55 0.73 2202 4714 55 3.030 7137 0.55 0.73 2402 4735 60 2.860 7349 0.54 0.72 2601 4748 65 2.720 7572 0.54 0.72 2801 4771 70 2.590 7765 0.54 0.71 3000 4764 75 2.480 7966 0.53 0.71 3200 4766 80 2.380 8154 0.53 0.71 3399 4755 85 2.290 8336 0.53 0.71 3599 4737 90 2.210 8518 0.53 0.70 3798 4720 95 2.130 8666 0.53 0.70 3998 4668 100 2.060 8823 0.53 0.70 4197 4625 105 2.000 8994 0.52 0.70 4397 4597 110 1.940 9139 0.52 0.70 4596 4543 115 1.890 9309 0.52 0.70 4796 4513 120 1.840 9456 0.52 0.69 4995 4461 *Note: Using the method described in Urban Storm Drainage Criteria Manual Volume 2. DETENTION POND CALCULATION: MODIFIED FAA METHOD w/ Ft Collins IDF Input Variables Results Required Detention Volume Fort Collins, Colorado 100-020 Odell Wine Project Project Number : Project Name : Permeable Pavers A = Project: Calc. By: Date: 0.860 <-- INPUT from impervious calcs 69.00 <-- INPUT from impervious calcs 0.6900 <-- CALCULATED 12 hours <-- from UDFCD Vol. 3 Table 3-2 0.8 <-- from UDFCD Vol. 3 Table 3-2 0.216 <-- UDFCD Vol. 3 Equation 3-1 0.016 <-- UDFCD Vol. 3 Equation 3-3 ** <-- INPUT from stage-storage table ** <-- CALCULATED from Figure EDB-3 dia (in) = ** <-- INPUT from Figure 5 n = ** <-- INPUT from Figure 5 t (in) = ** <-- INPUT from Figure 5 number of rows = ** <-- from WQ Depth and row spacing October 16, 2019 WATER QUALITY CALCULATIONS Permeable Pavers Required Storage & Outlet Works Circular Perforation Sizing **To be completed at final design Basin Area = Basin Percent Imperviousness = Basin Imperviousness Ratio = WQCV (watershed inches) = WQCV (ac-ft) = WQ Depth (ft) = Area Required Per Row, a (in2) = Drain Time Coefficient = Drain Time = Odell Wine Project F. Wegert Project Number : Project Name : Project Location : Pond No : 800 E. Lincoln Ave. 11,118 ft3 824 E. Lincoln Ave. 2,554 ft3 Total 13,672 ft3 Permeable Pavers 2,261 ft3 East Pond 9,620 ft3 Total 11,881 ft3 11,118 ft3 4,771 ft3 697 ft3 16,586 ft3 11,881 ft3 Required Volume for 824 E. Lincoln Ave. 4,705 ft3 30% 5,507 ft2 2.8 ft 6.0 in 4.0 in 3.0 ft 4,956 ft3 4,705 ft3 Required Volumes of 824 E. Lincoln Avenue Required Volume for 800 E. Lincoln Ave Required Water Quality Volume Design Depth of Subbase Total Required Volume 100-020 Odell Wine Project Fort Collins, Colorado Permeable Pavers Asbuilt Volume1 Area of Pavers Asbuilt Detention Volumes for 800 E. Lincoln Ave. Required Volume1 PERMEABLE PAVER VOLUME & SECTION Design Volume Required Volume Required Volume for 824 E. Lincoln Ave. Asbuilt Volume per 800 E. Lincoln Ave. Drainage Certification Permeable Paver Section Assumed Void Ratio per FCSM2 Calculated Depth of Subbase Paver & Levelling Course Depth (per FC standard details)3 Base Depth (per FC standard details)3 Notes: 1) All volumes from Addendum to Final Drainage Certification Memorandum for 2013 Odell Brew House Expansion by Northern Engineering dated 02/18/2014. 2) FCSM = Fort Collins Stormwater Manual. 3) Paver depths based on standard Fort Collins detail D-54. X X X X X D G G CTV CTV CTV E E E E T T AC SS SS D ST ST ST ST ST ST ST ST ST D D H Y D W C S VAULT ELEC CONTROL IRR CONTROL IRR CONTROL IRR CONTROL CONTROL IRR IRR MH VAULT ELEC VAULT CABLE VAULT ELEC D D D C.O. E VAULT ELEC V.P. ELEC BRKR E Historic Impervious Area Percent Impervious Asphalt and Concrete 11,379 ft2 100% 11,379 ft2 Roof 9,604 ft2 100% 9,604 ft2 Gravel 7,030 ft2 50% 3,515 ft2 Total 28,013 ft2 24,498 ft2 Asphalt and Concrete 11,465 ft2 100% 11,465 ft2 Roof 9,604 ft2 100% 9,604 ft2 Gravel 3,809 ft2 50% 1,905 ft2 Pavers 5,397 ft2 50% 2,699 ft2 Total 30,275 ft2 25,672 ft2 1,174 ft2 Yes Description Percent Impervious Proposed Concrete 2,052 ft2 100% 2,052 ft2 Proposed Gravel 1,637 ft2 50% 819 ft2 Proposed Pavers 5,397 ft2 50% 2,699 ft2 Total Proposed 3,689 ft2 2,871 ft2 Existing Concrete 2,306 ft3 100% 2,306 ft3 Existing Roof 2,881 ft2 100% 2,881 ft2 Total 5,187 ft2 5,187 ft2 Description Percent Impervious Proposed Concrete 1,826 ft2 100% 1,826 ft2 Total Proposed 1,826 ft2 1,826 ft2 61.1% 81.5% 5,195 ft2 3,291 ft2 63.3% Area Impervious Area Net New Impervious Area Does new impervious area exceed 1,000 sq. ft.? Percent Treated of Modified Vehicle Area New or Modified Vehicle Area New and Modified Impervious Areas Not Treated by Permeable Pavers Area Impervious Area New or Modified Vehicle Area with Treatment Proposed Impervious Area Area Impervious Area Percent of Treatment of New Impervious Area Percent Treatment of Pro. & Ex. Impervious Area Area Treated by Permeable Pavers Appendix D Erosion Control Report Drainage Report October 16, 2019 Odell Investments Erosion Control Report Erosion Control Report A comprehensive Erosion and Sediment Control Plan (along with associated details) has been 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 and/or wattles along the disturbed perimeter, gutter protection in the adjacent roadways and inlet protection at existing and 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 Final Utility Plans 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 may 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 Storm Water 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 E USDA 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 Natural Area, Colorado Resources Conservation Service August 22, 2019 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 (https://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 2 alternative means 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.................................................................................................................. 8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................ 11 Map Unit Descriptions.........................................................................................11 Larimer County Area, Colorado...................................................................... 13 64—Loveland clay loam, 0 to 1 percent slopes...........................................13 105—Table Mountain loam, 0 to 1 percent slopes...................................... 14 Soil Information for All Uses...............................................................................16 Soil Properties and Qualities.............................................................................. 16 Soil Erosion Factors........................................................................................16 K Factor, Whole Soil....................................................................................16 Soil Qualities and Features.............................................................................19 Hydrologic Soil Group................................................................................. 19 References............................................................................................................24 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 5 scientists classified and named the soils in the survey area, they compared the 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 Custom Soil Resource Report 6 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 7 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. 8 9 Custom Soil Resource Report Soil Map 4493120 4493130 4493140 4493150 4493160 4493170 4493180 4493190 4493200 4493210 4493220 4493230 4493240 4493250 4493120 4493130 4493140 4493150 4493160 4493170 4493180 4493190 4493200 4493210 4493220 4493230 4493240 4493250 494670 494680 494690 494700 494710 494720 494730 494740 494750 494760 494770 494670 494680 494690 494700 494710 494720 494730 494740 494750 494760 494770 40° 35' 24'' N 105° 3' 46'' W 40° 35' 24'' N 105° 3' 42'' W 40° 35' 19'' N 105° 3' 46'' W 40° 35' 19'' N 105° 3' 42'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 30 60 120 180 Feet 0 10 20 40 60 Meters Map Scale: 1:692 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. 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: 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 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 64 Loveland clay loam, 0 to 1 percent slopes 0.8 61.7% 105 Table Mountain loam, 0 to 1 percent slopes 0.5 38.3% Totals for Area of Interest 1.4 100.0% 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, Custom Soil Resource Report 11 onsite investigation is needed to define and locate the soils and miscellaneous areas. 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 12 Larimer County Area, Colorado 64—Loveland clay loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: jpx9 Elevation: 4,800 to 5,500 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 135 to 150 days Farmland classification: Prime farmland if irrigated Map Unit Composition Loveland and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Loveland Setting Landform: Flood plains, stream terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile H1 - 0 to 15 inches: clay loam H2 - 15 to 32 inches: clay loam, silty clay loam, loam H2 - 15 to 32 inches: very gravelly sand, gravelly sand, gravelly coarse sand H2 - 15 to 32 inches: H3 - 32 to 60 inches: H3 - 32 to 60 inches: H3 - 32 to 60 inches: Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.60 in/hr) Depth to water table: About 18 to 36 inches Frequency of flooding: Occasional Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Very slightly saline to slightly saline (2.0 to 4.0 mmhos/cm) Available water storage in profile: Very high (about 16.7 inches) Interpretive groups Land capability classification (irrigated): 3w Land capability classification (nonirrigated): 3w Hydrologic Soil Group: C Hydric soil rating: No Custom Soil Resource Report 13 Minor Components Aquolls Percent of map unit: 5 percent Landform: Swales Hydric soil rating: Yes Poudre Percent of map unit: 5 percent Hydric soil rating: No 105—Table Mountain loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: jpty Elevation: 4,800 to 5,600 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 135 to 150 days Farmland classification: Prime farmland if irrigated Map Unit Composition Table mountain and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Table Mountain Setting Landform: Flood plains, stream terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile H1 - 0 to 36 inches: loam H2 - 36 to 60 inches: loam, clay loam, silt loam H2 - 36 to 60 inches: H2 - 36 to 60 inches: Properties and qualities Slope: 0 to 1 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 (0.60 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Custom Soil Resource Report 14 Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 5.0 Available water storage in profile: Very high (about 18.0 inches) Interpretive groups Land capability classification (irrigated): 1 Land capability classification (nonirrigated): 3c Hydrologic Soil Group: B Ecological site: Overflow (R049XY036CO) Hydric soil rating: No Minor Components Caruso Percent of map unit: 7 percent Hydric soil rating: No Fluvaquentic haplustolls Percent of map unit: 4 percent Landform: Terraces Hydric soil rating: Yes Paoli Percent of map unit: 4 percent Hydric soil rating: No Custom Soil Resource Report 15 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 Erosion Factors Soil Erosion Factors are soil properties and interpretations used in evaluating the soil for potential erosion. Example soil erosion factors can include K factor for the whole soil or on a rock free basis, T factor, wind erodibility group and wind erodibility index. K Factor, Whole Soil Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by water. Factor K is one of six factors used in the Universal Soil Loss Equation (USLE) and the Revised Universal Soil Loss Equation (RUSLE) to predict the average annual rate of soil loss by sheet and rill erosion in tons per acre per year. The estimates are based primarily on percentage of silt, sand, and organic matter and on soil structure and saturated hydraulic conductivity (Ksat). Values of K range from 0.02 to 0.69. Other factors being equal, the higher the value, the more susceptible the soil is to sheet and rill erosion by water. "Erosion factor Kw (whole soil)" indicates the erodibility of the whole soil. The estimates are modified by the presence of rock fragments. 16 17 Custom Soil Resource Report Map—K Factor, Whole Soil 4493120 4493130 4493140 4493150 4493160 4493170 4493180 4493190 4493200 4493210 4493220 4493230 4493240 4493250 4493120 4493130 4493140 4493150 4493160 4493170 4493180 4493190 4493200 4493210 4493220 4493230 4493240 4493250 494670 494680 494690 494700 494710 494720 494730 494740 494750 494760 494770 494670 494680 494690 494700 494710 494720 494730 494740 494750 494760 494770 40° 35' 24'' N 105° 3' 46'' W 40° 35' 24'' N 105° 3' 42'' W 40° 35' 19'' N 105° 3' 46'' W 40° 35' 19'' N 105° 3' 42'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 30 60 120 180 Feet 0 10 20 40 60 Meters Map Scale: 1:692 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Soil Rating Lines .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Soil Rating Points .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Table—K Factor, Whole Soil Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 64 Loveland clay loam, 0 to 1 percent slopes .20 0.8 61.7% 105 Table Mountain loam, 0 to 1 percent slopes .37 0.5 38.3% Totals for Area of Interest 1.4 100.0% Rating Options—K Factor, Whole Soil Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Layer Options (Horizon Aggregation Method): Surface Layer (Not applicable) 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 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. Custom Soil Resource Report 19 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 20 21 Custom Soil Resource Report Map—Hydrologic Soil Group 4493120 4493130 4493140 4493150 4493160 4493170 4493180 4493190 4493200 4493210 4493220 4493230 4493240 4493250 4493120 4493130 4493140 4493150 4493160 4493170 4493180 4493190 4493200 4493210 4493220 4493230 4493240 4493250 494670 494680 494690 494700 494710 494720 494730 494740 494750 494760 494770 494670 494680 494690 494700 494710 494720 494730 494740 494750 494760 494770 40° 35' 24'' N 105° 3' 46'' W 40° 35' 24'' N 105° 3' 42'' W 40° 35' 19'' N 105° 3' 46'' W 40° 35' 19'' N 105° 3' 42'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 30 60 120 180 Feet 0 10 20 40 60 Meters Map Scale: 1:692 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. 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: 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 Table—Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 64 Loveland clay loam, 0 to 1 percent slopes C 0.8 61.7% 105 Table Mountain loam, 0 to 1 percent slopes B 0.5 38.3% Totals for Area of Interest 1.4 100.0% Rating Options—Hydrologic Soil Group Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Custom Soil Resource Report 23 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 24 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 25 Appendix F Historical Drainage Certifification Excerpts Final Drainage Certification Memorandum Date: February 3, 2014 Project: 2013 Odell Brew House Expansion Project No. 100-009 Fort Collins, Colorado Attn: Mr. Glen Schlueter City of Fort Collins – Stormwater Utility 700 Wood Street Fort Collins, Colorado 80521 Dear Glen: This memorandum serves to supplement the Commercial, Multi-Family and Subdivision Certification Checklist, as published on the City of Fort Collins’ website. Specifically, it is intended to document the modifications and current condition of the East Pond. Due to the transplanting of several mature trees from the adjacent Link-N-Greens construction site, as well as the presence of buried electrical lines and irrigation facilities, the East Pond fell short of the required detention storage volume when initially surveyed for certification purposes. An alternative design was subsequently developed, and vetted in the field with Wes Lamarque of Fort Collins Stormwater. While the pond was deficient in total volume, it met the requirements for site generated runoff from Odell Brewing Co. The shortage was purely due to the off-site volume burden from Fort Collins Monument and Stone (FCM&S). It is anticipated that FCM&S will construct their own detention pond, thereby relieving the 2,554 cu.ft. of storage volume currently imposed on the Odell East Pond. However, until said pond is built and certified, Odell will make an effort to provide the interim volume, or increased water quality measures as an offset. It is with those intentions in mind that the East Pond was modified after the aforementioned trees were transplanted. The pond bottom was over-excavated two feet. 4-in. of topsoil was then placed above 8-in. of sand, resulting in a nominal pond bottom approximately one foot lower than the original design (4939.0 instead of 4940.0). This puts the pond bottom slightly below the existing gravity outfall. While this is good from a low-impact development (LID) perspective, there is a strong objective to minimize the potential depth and frequency of standing water. For these reasons, a fourth dry well was added in addition to the sand bottom. 2013 Odell Brew House Expansion | Final Site Drainage Certification | 02.03.14 D:\Projects\100-009\Drainage\DrngCert\Odell_FinalDrngCertMemo_2014-02-03.docx Page 2 of 2 The permeable paver system was constructed pursuant to the approved plans and specifications. This provides roughly 2,261 cu.ft. of LID detention storage in the sub-surface aggregate void space. When combined with the 9,620 cu.ft. of open air detention volume, the East Pond provides approximately 11,881 cu.ft. of total storage. At this time it is kindly requested that the Temporary Certificate of Occupancy be switched to a permanent Certificate of Occupancy given the substantial completion of the drainage improvements. The attached Record Drawings and Checklist, as well as this memo, serve to document the constructed condition. The slight shortage in detention volume in the East Pond is not expected have adverse impacts to public health or safety. The additional trees and LID/water quality benefits employed are viewed as positive offsets to the storage volume that will ultimately reside on the FCM&S property. The Overall Site Drainage Certification for the 2013 Odell Brew House is based upon field survey information and site observation(s) conducted by Northern Engineering, as well as information and testimony supplied by the General Contractor. Please feel free to contact me if you have any questions. Sincerely, Nicholas W. Haws, PE, LEED AP cc: Ben Basalay – RB+B Architects Brian Cass – GH Phipps Construction Companies enc. 02.03.14 Addendum to Final Drainage Certification Memorandum Date: February 18, 2014 Project: 2013 Odell Brew House Expansion Project No. 100-009 Fort Collins, Colorado Attn: Mr. Wes Lamarque City of Fort Collins – Stormwater Utility 700 Wood Street Fort Collins, Colorado 80521 Dear Wes: This addendum letter is provided pursuant to your request to further document the interim volume shortage in the East Pond. According to the 04.22.13 Drainage Addendum Letter for the Odell Brewing Co. expansion applications (PDP120032 and MA130002), the required storage volume is 13,672 cu.ft. (11,118 cu.ft from Odell + 2,554 cu.ft. from Fort Collins Monument & Stone). The volume currently provided (per the 02.03.14 Odell Record Drawings) is 11,881 cu.ft. (2,261 cu.ft. under the pavers + 9,620 cu.ft. in the open pond). This results in an interim volume shortage of 1,791 cu.ft. (13,672 – 11,881). According to recent soils reports (Terracon Proj. No. 20125035), infiltration rates of the native soils range from 0.1 – 1 in/hr for upper lean clay and clayey sand soils to 2 – 6 in/hr for lower sands and gravels. I chose to conservatively use 0.25 in/hr for infiltration at the installed dry wells. There are four (4) dry wells, each 2 ft. diameter by 6 ft. deep. The total flow rate of all four dry wells combined using an infiltration rate of 0.25 in/hr is 0.26 cfs. The estimated time to drain 1,791 cu.ft. of volume at 0.26 cfs is 1.9 hrs. Since the volume in question can theoretically be drained in less than 2 hours, I feel the constructed pond remains adequate as-is. Please feel free to contact me if you have any questions. Sincerely, Nicholas W. Haws, PE, LEED AP 02.18.14 Appendix G FEMA Firmette USGS The National Map: Orthoimagery. Data refreshed April, 2019. National Flood Hazard Layer FIRMette 0 250 500 1,000 1,500 2,000 Feet Ü 105°4'3.11"W 40°35'35.94"N 105°3'25.66"W 40°35'8.62"N SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT HAZARD SPECIAL FLOOD AREAS Without Zone A, V, Base A99 Flood Elevation (BFE) With BFE or Depth Zone AE, AO, AH, VE, AR Regulatory Floodway 0.of 2% 1% Annual annual Chance chance Flood flood with Hazard, average Areas depth areasdrainage of less less than than one one foot square or with mile Zone X Future ChanceAnnual Conditions Flood Hazard 1% Zone X Area Levee.to with See Reduced Notes. Flood Risk due Zone X Area with Flood Risk due to LeveeZone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood Hazard Zone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This digital map flood complies maps if with it is FEMA's not void standards as described for the below. use of The accuracy basemap standards shown complies with FEMA's basemap The authoritative flood hazard NFHL information web services is derived provided directly by FEMA. from This the map was reflectnot exported changes on or 8/amendments 26/2019 at 9:subsequent 09:49 PM to and this does date and time. becomeor The superseded NFHL and effective by new data information over time. may change This elementsmap map image do not is appear: void if basemap the one or imagery, more of flood the following zone labels, legend, FIRM panel scale number, bar, map and creation FIRM effective date, community date. Map identifiers,images for unmapped regulatoryfor purposes. and unmodernized areas cannot be used Legend OTHER FLOOD AREAS HAZARD OF OTHER AREAS STRGUECNTUERREASL FEATURES OTHER MAP PANELS 8 1:6,000 B 20.2 The point pin selected displayed by the on the user map and is does an approximate not represent an authoritative property location. Map Pocket DR1 –Drainage Exhibit D ST ST C S W W C S C.O. CTV CTV CTV CTV CTV CTV CTV CTV CTV CTV CTV CTV CTV CTV C.O. C.O. T X AC X X X X X D ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST ST D MH VAULT CABLE D D D C.O. V.P. C.O. C.O. AC AC M X X X X X X X X X X ST ST ST ST UD UD UD UD UD UD UD UD 0.44 ac. A-1 0.03 ac. B 0.17 ac. OS-1 a-1 b os-1 0.03 ac. OS-2 0.19 ac. C 0.39 ac. A-2 os-2 a2 c EXISTING INLET EAST POND (EXISTING) EXISTING OUTLET STRUCTURE EXISTING STORM MH RIM=4946.15 INV IN=4942.40 (N) INV OUT=4942.33 (SW) EXISTING STORM MH RIM=4946.20 INV IN=4942.08 (N) INV IN=4942.12 (NE) INV OUT=4942.01 (S) EXISTING RETAINING WALL CONCRETE WALK CONCRETE WALK OUTDOOR PATIO EXISTING CONCRETE APRON EXISTING BUILDING (824 E. LINCOLN AVE.) ODELL BREWING COMPANY (800 E. LINCOLN AVE.) EXISTING OUTDOOR PATIO EXISTING PARKING LOT EX. OVERHEAD STRUCTURE EXISTING STORM MH PERMEABLE PAVERS PERMEABLE PAVERS EXISTING SIDEWALK EXISTING DOWNSPOUT (TYP.) EXISTING BOLLARD (TYP.) EXISTING VALLEY PAN PROPOSED RETAINING WALL PROPOSED BRIDGE PROPOSED INLET PROPOSED CLEANOUT (TYP.) PROPOSED BOULDER WALL PROPOSED (RE: LANDSCAPE ARCHITECT) VALLEY PAN RAISED PLANTER (RE: LANDSCAPE ARCHITECT) PROPOSED SWALE EXISTING STORM MH RIM=4947.83 (RECORD) INV IN=4943.22 (N) INV OUT=4943.23 (S) EXISTING 327.12 LF OF 15" HDPE STORM SEWER S = 0.25% PROPOSED INLET Sheet ODELL WINE PROJECT 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 E NGINEER ING N O R T H E RN FORT COLLINS: 301 North Howes Street, Suite 100, 80521 GREELEY: 820 8th Street, 80631 970.221.4158 northernengineering.com of 12 ( IN FEET ) 0 1 INCH = 20 FEET 20 20 40 60 NORTH 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 C602 DRAINAGE EXHIBIT 12 LEGEND: PROPOSED CONTOUR PROPOSED STORM SEWER PROPOSED SWALE EXISTING CONTOUR PROPERTY BOUNDARY DESIGN POINT A FLOW ARROW DRAINAGE BASIN LABEL DRAINAGE BASIN BOUNDARY PROPOSED SWALE SECTION 1 1 B2 1.45 ac PROPOSED AREA DRAIN INLET PROPOSED UNDERDRAIN UD of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 13, Sep 10, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 11, 2018—Aug 12, 2018 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 22 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: 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 Survey Area Data: Version 13, Sep 10, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 11, 2018—Aug 12, 2018 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 18 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 Survey Area Data: Version 13, Sep 10, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 11, 2018—Aug 12, 2018 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 10 GGG C.O. C.O. AC AC M G G G G E E E E E E X T T T X T T T T ST SS SS SS E E PROPOSED CONCRETE PROPOSED GRAVEL EXISTING CONCRETE EXISTING ROOF P:\100-020\DWG\DRNG\100-020_LID.DWG 824 E. LINCOLN AVENUE FORT COLLINS COLORADO Fort Collins: 301 N. Howes St., Ste. 100, 80521 Greeley: 820 8th Street, 80631 E NGINEER ING N O R T H E RN PHONE: 970.221.4158 www.northernengineering.com DESCRIPTION NEW IMPERVIOUS AREA AND LID TREATMENT DRAWN BY F. WEGERT DATE OCTOBER 16, 2019 PROJECT 100-020 DR-C1 SCALE DRAWING 1"=50' PAVERS LID TREATMENT OF IMPERVIOUS AREAS PROPOSED CONCRETE NEW IMPERVIOUS AREA NOT TREATED BY LID 2,881 ft2 2,306 ft2 1,637 ft2 2,052 ft2 5,397 ft2 TOTAL TREATED 8,058 ft 2 NEW IMPERVIOUS AREA TREATED 2,871 ft 2 1,826 ft2 NEW IMPERVIOUS AREA NOT TREATED 1,826 ft 2 PERCENT OF NEW IMPERVIOUS AREA TREATED BY LID 61.1% TOTAL NEW IMPERVIOUS AREA 2,871 ft2 PERCENT OF NEW & OLD IMPERVIOUS AREA TREATED BY LID 81.5% PERCENT OF NEW & MODIFIED VEHICLE AREA TREATED BY PAVERS 63.3% Tc = Project Location : Design Point C = Design Storm Page 1 of 1 100-020_Pond_FAA at 2-yr Historic.xls SCALE DRAWING 1"=50' LANDSCAPE 10,184 0% 0 LANDSCAPE 13,949 0% 0 9,645 8,645 2,711 9,645 11,352 9,645 2-yr T c (min) 10-yr T c (min) 100-yr T c (min) a-1 A-1 80 4946.87 4946.11 0.95% 7.6 7.6 4.8 N/A N/A N/A 126 4946.11 4945.71 0.32% 0.85 2.5 10.1 10.1 7.3 a-2 A-2 125 4947.50 4945.91 1.27% 6.5 6.5 2.9 N/A N/A N/A 170 4945.91 4945.35 0.33% 0.86 3.3 9.8 9.8 6.2 b B 25 4946.30 4945.39 3.64% 5.5 5.5 5.2 N/A N/A N/A 35 4945.39 4944.31 3.09% 2.63 0.2 5.7 5.7 5.4 c C 35 4947.50 4947.00 1.43% 6.1 6.1 4.9 N/A N/A N/A 225 4947.00 4945.88 0.50% 1.06 3.5 9.6 9.6 8.4 os-1 OS-1 69 4956.00 4947.50 12.32% 5.6 5.6 5.1 N/A N/A N/A 100 4947.50 4947.29 0.21% 0.69 2.4 8.0 8.0 7.6 os-2 OS-2 69 4956.00 4947.50 12.32% 6.1 6.1 5.7 N/A N/A N/A 23 4947.50 4947.00 2.17% 2.21 0.2 6.2 6.2 5.9 a-1 A-B 125 4947.50 4945.91 1.27% 7.9 7.9 4.6 N/A N/A N/A 317 4945.91 4939.00 2.18% 2.21 2.4 10.3 10.3 7.0 a-1 A-B-OS1 69 4956.00 4947.50 12.32% 3.2 3.2 2.2 N/A N/A N/A 316 4947.50 4946.71 0.25% 0.75 7.0 10.3 10.3 9.2 c C-OS2 69 4956.00 4947.50 12.32% 4.5 4.5 3.7 N/A N/A N/A 225 4947.50 4944.31 1.42% 1.79 2.1 6.6 6.6 5.8 Tc = Ti + Tt (Equation RO-2) Velocity (Gutter Flow), V = 20·S½ Velocity (Swale Flow), V = 15·S½ Combined Basins PROPOSED TIME OF CONCENTRATION COMPUTATIONS F. Wegert October 16,2019 Design Point Basin(s) Overland Flow Swale Flow Time of Concentration NOTE: C-value for overland flows over grassy surfaces; C = 0.25 Gutter/Swale Flow, Time of Concentration: Gutter Flow Overland Flow, Time of Concentration: Tt = L / 60V (Equation RO-4) ( ) 3 1 1 . 87 1 . 1 * S C Cf L Ti − = 10/15/2019 1:49 PM P:\100-020\Drainage\Hydrology\100-020_FC Rational_Developed.xlsx\Tc Asphalt, Concrete Composite Runoff Coefficient with Adjustment 10/15/2019 1:48 PM P:\100-020\Drainage\Hydrology\100-020_FC Rational_Developed.xlsx\Composite C 2-yr T c (min) 10-yr T c (min) 100-yr T c (min) ha HA 125 4948.00 4945.91 1.67% 6.6 6.6 3.4 N/A N/A N/A 248 4945.91 4939.08 2.75% 2.49 1.7 8.2 8.2 5.0 hb HB 16 4945.85 4945.74 0.69% 4.3 4.3 3.0 N/A N/A N/A 152 4945.74 4944.31 0.94% 1.45 1.7 6.0 6.0 5.0 hos HOS 69 4953.00 4948.00 7.25% 7.2 7.2 6.8 N/A N/A N/A 100 4948.00 4947.29 0.71% 1.26 1.3 8.5 8.5 8.1 a-b A-B 125 4948.00 4945.91 1.67% 7.5 7.5 4.5 N/A N/A N/A 248 4945.91 4939.08 2.75% 2.49 1.7 9.1 9.1 6.2 Tc = Ti + Tt (Equation RO-2) Velocity (Gutter Flow), V = 20·S½ Velocity (Swale Flow), V = 15·S½ Combined Basins HISTORIC TIME OF CONCENTRATION COMPUTATIONS F. Wegert October 16,2019 Design Point Basin(s) Overland Flow Swale Flow Time of Concentration NOTE: C-value for overland flows over grassy surfaces; C = 0.25 Gutter/Swale Flow, Time of Concentration: Gutter Flow Overland Flow, Time of Concentration: Tt = L / 60V (Equation RO-4) ( ) 3 1 1 . 87 1 . 1 * S C Cf L Ti − = 10/15/2019 1:51 PM P:\100-020\Drainage\Hydrology\100-020_FC Rational_Historic.xlsx\Tc