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HomeMy WebLinkAboutUNCOMMON (310 S. COLLEGE) - PDP - PDP150013 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTJuly 15, 2015 PRELIMINARY DRAINAGE AND EROSION CONTROL REPORT FOR UNCOMMON Fort Collins, Colorado Prepared for: CA Ventures 161 N. Clark St., Suite 2050 Chicago, IL 60601 Prepared by: 301 N. Howes St., Suite 100 Fort Collins, Colorado 80521 Phone: 970.221.4158 Fax: 970.221.4159 www.northernengineering.com Project Number: 1104-001  This Drainage Report is consciously provided as a PDF. Please consider the environment before printing this document in its entirety. When a hard copy is absolutely necessary, we recommend double-sided printing. July 15, 2015 City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, Colorado 80521 RE: Preliminary Drainage and Erosion Control Report for UNCOMMON Dear Staff: Northern Engineering is pleased to submit this Preliminary Drainage and Erosion Control Report for your review. This report accompanies the Project Development Plan submittal for the proposed Uncommon development project. This report has been prepared in accordance to Fort Collins Stormwater Criteria Manual (FCSCM), and serves to document the stormwater impacts associated with the proposed project. We understand that review by the City is to assure general compliance with standardized criteria contained in the FCSCM. If you should have any questions as you review this report, please feel free to contact us. Sincerely, NORTHERN ENGINEERING SERVICES, INC. Aaron Cvar, PE Project Engineer Uncommonl Preliminary Drainage Report TABLE OF CONTENTS I. GENERAL LOCATION AND DESCRIPTION ................................................................... 1 A. Location ............................................................................................................................................. 1 B. Description of Property ..................................................................................................................... 2 C. Floodplain.......................................................................................................................................... 4 II. DRAINAGE BASINS AND SUB-BASINS ....................................................................... 5 A. Major Basin Description .................................................................................................................... 5 B. Sub-Basin Description ....................................................................................................................... 5 III. DRAINAGE DESIGN CRITERIA ................................................................................... 5 A. Regulations........................................................................................................................................ 5 B. Four Step Process .............................................................................................................................. 5 C. Development Criteria Reference and Constraints ............................................................................ 6 D. Hydrological Criteria ......................................................................................................................... 6 E. Hydraulic Criteria .............................................................................................................................. 6 F. Modifications of Criteria ................................................................................................................... 7 IV. DRAINAGE FACILITY DESIGN .................................................................................... 7 A. General Concept ............................................................................................................................... 7 B. Specific Details .................................................................................................................................. 7 V. CONCLUSIONS ........................................................................................................ 8 A. Compliance with Standards .............................................................................................................. 8 B. Drainage Concept .............................................................................................................................. 8 APPENDICES: APPENDIX A.1 - Rational Method Hydrologic Computations APPENDIX A.2 - Existing and Proposed Impervious Areas Exhibit APPENDIX B.1 - Erosion Control Report APPENDIX C.1 - USDA Soils Report Uncommonl Preliminary Drainage Report LIST OF FIGURES: Figure 1 – Aerial Photograph ................................................................................................ 2 Figure 2– Proposed Site Plan ................................................................................................ 3 Figure 3 – Existing Floodplains ............................................................................................. 4 MAP POCKET: Proposed Drainage Exhibit Uncommon Preliminary Drainage Report 1 I. GENERAL LOCATION AND DESCRIPTION A. Location Vicinity Map 1. The project site is located in the southwest 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. 2. The project site is located at the southeast corner of College Avenue and Olive Street. 3. The project site lies within the Old Town Basin. A portion of the site drains to the existing storm sewer system in College Avenue, which is conveyed north in College Avenue. The majority of the site drains via surface flow into the adjacent curb and gutter of Olive Street. Runoff is conveyed to existing inlets and storm system within Olive Street. Water quality treatment for 50% of the site is provided for in the Udall Natural Area water treatment facility. Per the Old Town Basin Master Plan requirements, as long as site imperviousness is not increased by more than 5000 square feet, detention is not required for the site. The proposed site plan proposes less than a 5000 square foot increase in imperviousness; therefore, detention is not required. However, the site still must meet current City Low Impact Design (LID) Uncommon Preliminary Drainage Report 2 requirements. Several water quality treatment methods are proposed for the site, and are described in further detail below. 4. As this is an infill site, the area surrounding the site is fully developed. 5. No offsite flows enter the site from the north, south, west, or east. Adjacent areas to the south and east are directed via sheet flow into adjacent alleyways. Adjacent areas to the north and west are directed into the adjacent curb and gutters of College Ave. and Olive St. B. Description of Property 1. The development area is roughly 0.8 net acres. Figure 1 – Aerial Photograph 2. The subject property is currently composed of existing buildings, and a large paved parking area. Previously, the “Perkins” restaurant occupied the property. Existing ground slopes are mild to moderate (i.e., 1 - 6±%) through the interior of the property. General topography slopes from southwest to northeast. Uncommon Preliminary Drainage Report 3 3. 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 of Fort Collins loam (Hydrologic Soil Group C). 4. The proposed project site plan (please see Figure 2, below) is composed of retail development and a multi-level parking structure. A portion of the parking structure will be sub-surface. Associated site work, water, and sewer lines will be constructed with the development. Current City Low Impact Design (LID) requirements will be implemented with the project, and will consist of several LID features which are discussed in Section IV, below. Figure 2– Proposed Site Plan 5. There are no known irrigation laterals crossing the site. 6. The proposed land use is a downtown hotel development. Uncommon Preliminary Drainage Report 4 C. Floodplain 1. The project site is encroached by a City designated 100-year floodplain, as shown in Figure 3, below. Figure 3 –Area Floodplain Mapping 2. A minimum of 18-inches of freeboard will be provided at Final design from base (100-year) flood elevation in adjacent Right of Way. This freeboard level will be applied to either the design of finished floor elevations, or the minimum level of flood proofing measures. Uncommon Preliminary Drainage Report 5 II. DRAINAGE BASINS AND SUB-BASINS A. Major Basin Description 3. The project site lies within the Old Town Basin. Water quality treatment for 50% of the site is provided for in the Udall Natural Area water treatment facility. Per the Old Town Basin Master Plan requirements, as long as site imperviousness is not increased by more than 5000 square feet, detention is not required for the site. The proposed site plan proposes less than a 5000 square foot increase in imperviousness; therefore, detention is not required. However, the site still must meet current City Low Impact Design (LID) requirements. Several water quality treatment methods are proposed for the site, and are described in further detail below. B. Sub-Basin Description 1. The subject property historically drains overland from southwest to northeast. Runoff from the majority of the site has historically been collected in the existing Montezuma Fuller Alleyway which directs flows north into the south flowline of Olive Street. The proposed site plan will generally maintain existing runoff patterns. 2. A more detailed description of the project drainage patterns is provided below. III. DRAINAGE DESIGN CRITERIA A. Regulations There are no optional provisions outside of the FCSCM proposed with the proposed project. B. Four Step Process The overall stormwater management strategy employed with the proposed project utilizes the “Four Step Process” to minimize adverse impacts of urbanization on receiving waters. The following is a description of how the proposed development has incorporated each step. Step 1 – Employ Runoff Reduction Practices Several techniques have been utilized with the proposed development to facilitate the reduction of runoff peaks, volumes, and pollutant loads as the site is developed from the current use by implementing multiple Low Impact Development (LID) strategies including: Conserving existing amenities in the site including the existing vegetated areas. Providing vegetated open areas throughout the site to reduce the overall impervious area and to minimize directly connected impervious areas (MDCIA). Routing flows, to the extent feasible, through vegetated swales to increase time of concentration, promote infiltration and provide initial water quality. Step 2 – Implement BMPs That Provide a Water Quality Capture Volume (WQCV) with Slow Release The efforts taken in Step 1 will facilitate the reduction of runoff; however, urban development of this intensity will still generate stormwater runoff that will require additional BMPs and water quality. The majority of stormwater runoff from the site will ultimately be intercepted and treated using extended detention methods prior to exiting the site. Uncommon Preliminary Drainage Report 6 Step 3 – Stabilize Drainageways There are no major drainageways within the subject property. While this step may not seem applicable to proposed development, the project indirectly helps achieve stabilized drainageways nonetheless. By providing water quality treatment, where none previously existed, sediment with erosion potential is removed from downstream drainageway systems. Furthermore, this project will pay one-time stormwater development fees, as well as ongoing monthly stormwater utility fees, both of which help achieve City-wide drainageway stability. Step 4 – Implement Site Specific and Other Source Control BMPs. The proposed project will improve upon site specific source controls compared to historic conditions: The proposed development will provide LID features which enhance water quality; thus, eliminating sources of potential pollution previously left exposed to weathering and runoff processes. C. Development Criteria Reference and Constraints The subject property is surrounded by currently developed properties. Thus, several constraints have been identified during the course of this analysis that will impact the proposed drainage system including: Existing elevations along the property lines will generally be maintained. As previously mentioned, overall drainage patterns of the existing site will be maintained. Elevations of existing downstream facilities that the subject property will release to will be maintained. D. Hydrological Criteria 1. The City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, as depicted in Figure RA-16 of the FCSCM, serve as the source for all hydrologic computations associated with the proposed development. Tabulated data contained in Table RA-7 has been utilized for Rational Method runoff calculations. 2. The Rational Method has been employed to compute stormwater runoff utilizing coefficients contained in Tables RO-11 and RO-12 of the FCSCM. 3. Three separate design storms have been utilized to address distinct drainage scenarios. A fourth design storm has also been computed for comparison purposes. The first design storm considered is the 80th percentile rain event, which has been employed to design the project’s water quality features. The second event analyzed is the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The third event considered is the “Major Storm,” which has a 100-year recurrence interval. The fourth storm computed, for comparison purposes only, is the 10-year event. 4. No other assumptions or calculation methods have been used with this development that are not referenced by current City of Fort Collins criteria. E. Hydraulic Criteria 1. As previously noted, the subject property maintains historic drainage patterns. 2. All drainage facilities proposed with the project are designed in accordance with criteria outlined in the FCSCM and/or the Urban Drainage and Flood Control District (UDFCD) Urban Storm Drainage Criteria Manual. Uncommon Preliminary Drainage Report 7 3. As stated above, the subject property is not located in a City designated 100-year floodplain. The proposed project does not propose to modify any natural drainageways. F. Modifications of Criteria 1. The proposed development is not requesting any modifications to criteria at this time. IV. DRAINAGE FACILITY DESIGN A. General Concept 1. The main objectives of the project drainage design are to maintain existing drainage patterns, and to ensure no adverse impacts to any adjacent properties. 2. Onsite LID features will be provided and will enhance water quality. These measures are discussed further below. 3. Drainage patterns anticipated for drainage basins shown in the Drainage Exhibit are described below. Drainage basins have been defined for preliminary design purposes and are subject to change at Final design; however, general drainage patterns and concepts are not expected to be significantly altered. Basin 1 Basin 1 will generally drain via rooftop flow and roof drains which will direct drainage into the adjacent College Avenue Right of Way. Drainage within College Avenue is directed into a series of combination inlets located just south of the intersection of College and Olive Street. Basin 2 Basin 2 will generally drain via sheet flow into LID features and then into the adjacent Montezuma Fuller Alley. The alley currently accepts the majority of historic flows from the property and will continue with this pattern. The alley currently consists of a concrete paved section with a reverse crown and drains from south to north into the south flowline of Olive Street. This historic drainage pattern will be maintained with the proposed site plan. Basin 3 Basin 3 will generally drain via sheet flow into a permeable paver system proposed for the area encompassed by this basin. The proposed site plan shows a paseo/pocket park in this area. Flows above the absorption capacity of the paver system in this area will sheet flow east into the adjacent Montezuma Fuller Alley, which will convey flows into Olive Street. A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of this report. Runoff computations for these basins based on the Rational Method is provided in Appendix A. B. Specific Details 1. As stated previously, water quality treatment for 50% of the site is provided for in the Udall Natural Area water treatment facility; thus, the proposed LID measures are being proposed in the spirit of providing beyond the standard 50% LID requirement. Low Impact Design (LID) measures currently being Uncommon Preliminary Drainage Report 8 considered for incorporation into the site design include: - In-Line Filters on Roof Drains - Mechanical separator for the parking structure - Permeable pavers in the pocket park/paseo Details of this design will be provided at Final design. Preliminary locations of paver fields are noted on the Drainage Exhibit. 2. The current site plan utilizes a multi-level parking structure for all onsite parking. Because of this, the site is excempt from the 25% permeable pavement metric. 3. Final design details, construction documentation, and Standard Operating Procedures (SOP) Manual shall be provided to the City of Fort Collins for review prior to Final Development Plan approval. A final copy of the approved SOP manual shall be provided to City and must be maintained on-site by the entity responsible for the facility maintenance. Annual reports must also be prepared and submitted to the City discussing the results of the maintenance program (i.e. inspection dates, inspection frequency, volume loss due to sedimentation, corrective actions taken, etc.). 4. Proper maintenance of the drainage facilities designed with the proposed development is a critical component of their ongoing performance and effectiveness. V. CONCLUSIONS A. Compliance with Standards 1. The drainage design proposed with the proposed project complies with the City of Fort Collins’ Stormwater Criteria Manual. 2. The drainage design proposed with this project complies with requirements for the Old Town Basin. 3. The drainage plan and stormwater management measures proposed with the proposed development are compliant with all applicable State and Federal regulations governing stormwater discharge. B. Drainage Concept 1. The drainage design proposed with this project will effectively limit any potential damage associated with its stormwater runoff by compliance with requirements set forth in current City master plans. 2. The drainage concept for the proposed development is consistent with requirements for the Old Town Basin and the Downtown River District Final Design Report. Uncommon Preliminary Drainage Report 9 References 1. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No. 174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code. 2. Larimer County Urban Area Street Standards, Adopted January 2, 2001, Repealed and Reenacted, Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007. 3. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation Service, United States Department of Agriculture. 4. Old Town Master Drainage Plan, Baseline Hydraulics, Volume II, Anderson Consulting, July 15, 2003. 5. Downtown River District Final Design Report, Ayres, February 2012. 6. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control District, Wright-McLaughlin Engineers, Denver, Colorado, Revised April 2008. APPENDIX A.1 RATIONAL METHOD HYDROLOGIC COMPUTATIONS CHARACTER OF SURFACE: Runoff Coefficient Percentage Impervious Project: 1104-001 Streets, Parking Lots, Roofs, Alleys, and Drives: Calculations By: ATC Asphalt ……....……………...……….....…...……………….…………………………………. 0.95 100% Date: Concrete …….......……………….….……….………………..….……………………………… 0.95 90% Gravel ……….…………………….….…………………………..………………………………. 0.50 40% Roofs …….…….………………..……………….…………………………………………….. 0.95 90% Pavers…………………………...………………..…………………………………………….. 0.40 22% Lawns and Landscaping Sandy Soil ……..……………..……………….…………………………………………….. 0.15 0% Clayey Soil ….….………….…….…………..………………………………………………. 0.25 0% 2-year Cf = 1.00 100-year Cf = 1.25 Basin ID Basin Area (s.f.) Basin Area (ac) Area of Asphalt (ac) Area of Concrete (ac) Area of Roofs (ac) Area of Pavers (ac) Area of Lawn, Rain Garden, or Landscaping (ac) 2-year Composite Runoff Coefficient 10-year Composite Runoff Coefficient 100-year Composite Runoff Coefficient Composite % Imperv. 1 5756 0.13 0.00 0.00 0.10 0.00 0.03 0.78 0.78 0.98 0.69 2 27125 0.62 0.00 0.00 0.62 0.00 0.00 0.95 0.95 1.00 0.90 3 2148 0.05 0.00 0.00 0.00 0.05 0.00 0.40 0.40 0.50 0.22 DEVELOPED COMPOSITE % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS Runoff Coefficients are taken from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards, Table 3-3. % Impervious taken from UDFCD USDCM, Volume I. 10-year Cf = 1.00 July 1, 2015 Overland Flow, Time of Concentration: Project: 1104-001 Calculations By: Date: Gutter/Swale Flow, Time of Concentration: Tt = L / 60V Tc = Ti + Tt (Equation RO-2) Velocity (Gutter Flow), V = 20·S½ Velocity (Swale Flow), V = 15·S½ NOTE: C-value for overland flows over grassy surfaces; C = 0.25 Is Length >500' ? C*Cf (2-yr Cf=1.00) C*Cf (10-yr Cf=1.00) C*Cf (100-yr Cf=1.25) Length, L (ft) Slope, S (%) Ti 2-yr (min) Ti 10-yr (min) Ti 100-yr (min) Length, L (ft) Slope, S (%) Velocity, V (ft/s) Tt (min) Length, L (ft) Slope, S (%) Velocity, V (ft/s) Tt (min) 2-yr Tc Rational Method Equation: Project: 1104-001 Calculations By: Date: From Section 3.2.1 of the CFCSDDC Rainfall Intensity: 1 1 0.13 5 5 5 0.78 0.78 0.98 2.85 4.87 9.95 0.30 0.50 1.29 2 2 0.62 5 5 5 0.95 0.95 1.00 2.85 4.87 9.95 1.69 2.88 6.20 3 3 0.05 5 5 5 0.40 0.40 0.50 2.85 4.87 9.95 0.06 0.10 0.25 Area, A (acres) Intensity, i2 (in/hr) 100-yr Tc (min) DEVELOPED RUNOFF COMPUTATIONS C100 Design Point Flow, Q100 (cfs) Flow, Q2 (cfs) 10-yr Tc (min) 2-yr Tc (min) C2 Flow, Q10 (cfs) Intensity, i100 (in/hr) Basin(s) ATC July 1, 2015 Intensity, i10 (in/hr) Rainfall Intensity taken from the City of Fort Collins Storm Drainage Design Criteria (CFCSDDC), Figure 3.1 C10 Q  C f  C i  A DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Figure RO-1—Estimate of Average Overland Flow Velocity for Use With the Rational Formula 2007-01 RO-13 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Table RO-3—Recommended Percentage Imperviousness Values Land Use or Surface Characteristics Percentage Imperviousness Business: Commercial areas 95 Neighborhood areas 85 Residential: Single-family * Multi-unit (detached) 60 Multi-unit (attached) 75 Half-acre lot or larger * Apartments 80 Industrial: Light areas 80 Heavy areas 90 Parks, cemeteries 5 Playgrounds 10 Schools 50 Railroad yard areas 15 Undeveloped Areas: Historic flow analysis 2 Greenbelts, agricultural 2 Off-site flow analysis (when land use not defined) 45 Streets: Paved 100 Gravel (packed) 40 Drive and walks 90 Roofs 90 Lawns, sandy soil 0 Lawns, clayey soil 0 * See Figures RO-3 through RO-5 for percentage imperviousness. C A = K A + ( 1 . 31 i 3 − 1 . 44 i 2 + 1 . 135 i − 0 . 12 ) for CA ≥ 0, otherwise CA = 0 (RO-6) C CD = K CD + ( 0 . 858 i 3 − 0 . 786 i 2 + 0 . 774 i + 0 . 04 ) (RO-7) C B = (CA + C CD ) 2 2007-01 RO-9 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Table RO-5— Runoff Coefficients, C Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0.04 0.15 0.25 0.37 0.44 0.50 5% 0.08 0.18 0.28 0.39 0.46 0.52 10% 0.11 0.21 0.30 0.41 0.47 0.53 15% 0.14 0.24 0.32 0.43 0.49 0.54 20% 0.17 0.26 0.34 0.44 0.50 0.55 25% 0.20 0.28 0.36 0.46 0.51 0.56 30% 0.22 0.30 0.38 0.47 0.52 0.57 35% 0.25 0.33 0.40 0.48 0.53 0.57 40% 0.28 0.35 0.42 0.50 0.54 0.58 45% 0.31 0.37 0.44 0.51 0.55 0.59 50% 0.34 0.40 0.46 0.53 0.57 0.60 55% 0.37 0.43 0.48 0.55 0.58 0.62 60% 0.41 0.46 0.51 0.57 0.60 0.63 65% 0.45 0.49 0.54 0.59 0.62 0.65 70% 0.49 0.53 0.57 0.62 0.65 0.68 75% 0.54 0.58 0.62 0.66 0.68 0.71 80% 0.60 0.63 0.66 0.70 0.72 0.74 85% 0.66 0.68 0.71 0.75 0.77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 TYPE B NRCS HYDROLOGIC SOILS GROUP 0% 0.02 0.08 0.15 0.25 0.30 0.35 5% 0.04 0.10 0.19 0.28 0.33 0.38 10% 0.06 0.14 0.22 0.31 0.36 0.40 15% 0.08 0.17 0.25 0.33 0.38 0.42 20% 0.12 0.20 0.27 0.35 0.40 0.44 25% 0.15 0.22 0.30 0.37 0.41 0.46 30% 0.18 0.25 0.32 0.39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0.36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 50% 0.29 0.35 0.40 0.46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0.37 0.41 0.46 0.51 0.54 0.56 65% 0.41 0.45 0.49 0.54 0.57 0.59 70% 0.45 0.49 0.53 0.58 0.60 0.62 75% 0.51 0.54 0.58 0.62 0.64 0.66 80% 0.57 0.59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0.71 0.73 0.75 0.78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% 0.89 0.90 0.92 0.94 0.95 0.96 2007-01 RO-11 Urban Drainage and Flood Control District RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) TABLE RO-5 (Continued)—Runoff Coefficients, C Percentage Imperviousness Type A NRCS Hydrologic Soils Group 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0.00 0.00 0.05 0.12 0.16 0.20 5% 0.00 0.02 0.10 0.16 0.20 0.24 10% 0.00 0.06 0.14 0.20 0.24 0.28 15% 0.02 0.10 0.17 0.23 0.27 0.30 20% 0.06 0.13 0.20 0.26 0.30 0.33 25% 0.09 0.16 0.23 0.29 0.32 0.35 30% 0.13 0.19 0.25 0.31 0.34 0.37 35% 0.16 0.22 0.28 0.33 0.36 0.39 40% 0.19 0.25 0.30 0.35 0.38 0.41 45% 0.22 0.27 0.33 0.37 0.40 0.43 50% 0.25 0.30 0.35 0.40 0.42 0.45 55% 0.29 0.33 0.38 0.42 0.45 0.47 60% 0.33 0.37 0.41 0.45 0.47 0.50 65% 0.37 0.41 0.45 0.49 0.51 0.53 70% 0.42 0.45 0.49 0.53 0.54 0.56 75% 0.47 0.50 0.54 0.57 0.59 0.61 80% 0.54 0.56 0.60 0.63 0.64 0.66 85% 0.61 0.63 0.66 0.69 0.70 0.72 90% 0.69 0.71 0.73 0.76 0.77 0.79 95% 0.78 0.80 0.82 0.84 0.85 0.86 100% 0.89 0.90 0.92 0.94 0.95 0.96 RO-12 2007-01 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Figure RO-3— Watershed Imperviousness, Single-Family Residential Ranch Style Houses 2007-01 RO-15 Urban Drainage and Flood Control District RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) Figure RO-4—Watershed Imperviousness, Single-Family Residential Split-Level Houses RO-16 2007-01 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Figure RO-5—Watershed Imperviousness, Single-Family Residential Two-Story Houses Figure RO-6—Runoff Coefficient, C, vs. Watershed Percentage Imperviousness NRCS Hydrologic Soil Group A 2007-01 RO-17 Urban Drainage and Flood Control District RUNOFF DRAINAGE CRITERIA MANUAL (V. 1) Figure RO-7—Runoff Coefficient, C, vs. Watershed Percentage Imperviousness NRCS Hydrologic Soil Group B Figure RO-8—Runoff Coefficient, C, vs. Watershed Percentage Imperviousness NRCS Hydrologic Soil Groups C and D RO-18 2007-01 Urban Drainage and Flood Control District APPENDIX A.2 EXISTING AND PROPOSED IMPERVIOUS AREAS EXHIBIT W W E E E E W W T T FO FO E E E E E E E T T T T CTV CTV CTV CTV W W W W W FO FO FO FO G G G G G E E E E E E E E E E E LIGHTED "PERKINS" SIGN SINGLE STORY COMMERCIAL W/BRICK, WOOD & STUCCO FFE = 4994.28 SS SS SS SS 6'x10' SHED MH ELEC ELEC T VAULT CABLE S ELEC ELEC VAULT T ELEC VAULT ELEC APPENDIX B.1 WATER EROSION CONTROL REPORT Uncommon Preliminary Erosion Control Report EROSION CONTROL REPORT A comprehensive Erosion and Sediment Control Plan (along with associated details) will be included with the final construction drawings. It should be noted, however, that any such Erosion and Sediment Control Plan serves only as a general guide to the Contractor. Staging and/or phasing of the BMPs depicted, and additional or different BMPs from those included may be necessary during construction, or as required by the authorities having jurisdiction. It shall be the responsibility of the Contractor to ensure erosion control measures are properly maintained and followed. The Erosion and Sediment Control Plan is intended to be a living document, constantly adapting to site conditions and needs. The Contractor shall update the location of BMPs as they are installed, removed or modified in conjunction with construction activities. It is imperative to appropriately reflect the current site conditions at all times. The Erosion and Sediment Control Plan shall address both temporary measures to be implemented during construction, as well as permanent erosion control protection. Best Management Practices from the Volume 3, Chapter 7 – Construction BMPs will be utilized. Measures may include, but are not limited to, silt fencing along the disturbed perimeter, gutter protection in the adjacent roadways and inlet protection at 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 the Utility Plans. The Final Plans will contain a full-size Erosion Control sheet 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 the Development Agreement for the development. Also, the Site Contractor for this project will be required to secure a Stormwater Construction General Permit from the Colorado Department of Public Health and Environment (CDPHE), Water Quality Control Division – Stormwater Program, prior to any earth disturbance activities. Prior to securing said permit, the Site Contractor shall develop a comprehensive StormWater Management Plan (SWMP) pursuant to CDPHE requirements and guidelines. The SWMP will further describe and document the ongoing activities, inspections, and maintenance of construction BMPs. APPENDIX C.1 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 July 14, 2015 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/portal/ nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (http:// offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means 2 for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................7 Soil Map................................................................................................................8 Legend..................................................................................................................9 Map Unit Legend................................................................................................10 Map Unit Descriptions........................................................................................10 Larimer County Area, Colorado......................................................................12 35—Fort Collins loam, 0 to 3 percent slopes..............................................12 References............................................................................................................13 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil scientists classified and named the soils in the survey area, they compared the 5 individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil- landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 6 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 7 8 Custom Soil Resource Report Soil Map 4492510 4492520 4492530 4492540 4492550 4492560 4492570 4492580 4492590 4492600 4492510 4492520 4492530 4492540 4492550 4492560 4492570 4492580 4492590 4492600 493490 493500 493510 493520 493530 493540 493550 493490 493500 493510 493520 493530 493540 493550 40° 35' 3'' N 105° 4' 37'' W 40° 35' 3'' N 105° 4' 34'' W 40° 35' 0'' N 105° 4' 37'' W 40° 35' 0'' N 105° 4' 34'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 20 40 80 120 Feet 0 5 10 20 30 Meters Map Scale: 1:462 if printed on A portrait (8.5" x 11") sheet. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of Map Unit Legend Larimer County Area, Colorado (CO644) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 35 Fort Collins loam, 0 to 3 percent slopes 1.0 100.0% Totals for Area of Interest 1.0 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. Custom Soil Resource Report 10 An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha- Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 11 Larimer County Area, Colorado 35—Fort Collins loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2tlnc Elevation: 4,020 to 6,730 feet Mean annual precipitation: 14 to 16 inches Mean annual air temperature: 46 to 48 degrees F Frost-free period: 143 to 154 days Farmland classification: Prime farmland if irrigated Map Unit Composition Fort collins and similar soils: 85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Fort Collins Setting Landform: Interfluves Down-slope shape: Linear Across-slope shape: Linear Parent material: Pleistocene or older alluvium derived from igneous, metamorphic and sedimentary rock and/or eolian deposits Typical profile Ap - 0 to 4 inches: loam Bt1 - 4 to 9 inches: clay loam Bt2 - 9 to 16 inches: clay loam Bk1 - 16 to 29 inches: loam Bk2 - 29 to 80 inches: loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.20 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 12 percent Salinity, maximum in profile: Nonsaline (0.1 to 1.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 0.5 Available water storage in profile: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 4c Hydrologic Soil Group: C Ecological site: Loamy Plains (R067BY002CO) Custom Soil Resource Report 12 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 13 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 14 MAP POCKET DRAINAGE EXHIBITS FDC MH CONTROL IRR CONTROL IRR ST ST ST ST ST ST ST ST ST ST OLIVE STREET (100' PUBLIC R.O.W.) SOUTH COLLEGE AVENUE (140' PUBLIC R.O.W.) MONTEZUMA FULLER ALLEY (20' PUBLIC R.O.W.) OWNER: 330 LLC 2775 IRIS AVE BOULDER, CO 80304 OWNER: REMINGTON PROPERTIES, LLC 1054 MESSARA DRIVE FORT COLLINS, CO 80524 OWNER: REMINGTON RENTAL PROPERTIES, LLC 1054 MESSARA DRIVE FORT COLLINS, CO 80524 OWNER: ADP SCREENING AND SELECTION SERVICES INC. MAILSTOP 325 ROSELAND, NJ 07068-1728 1 2 3 3 1 2 EXISTING INLETS EXISTING STORM DRAIN PROPOSED STORM MANHOLE PROPOSED STORM DRAIN MECHANICAL SEPARATOR NORTH DRAWING FILENAME: D:\Projects\1104-001\Dwg\Drng\1104-001_DRNG.dwg LAYOUT NAME: C600 DATE: Jul 15, 2015 - 1:29pm CAD OPERATOR: aaron LIST OF XREFS: [1104-001_xEXST] [1104-001_xSITE] [NES-xborder] [1104-001_xUTIL] [1104-001_xGRAD] [1104-001_xTOPO] 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 N O R T H E RN 07/15/15 301 North Howes Street, Suite 010 Fort Collins, Colorado 80521 www.northernengineering.com Phone: 970.221.4158 Of X Sheets C600 ( IN FEET ) 1 inch = ft. 20 0 20 Feet 20 40 60 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 R LEGEND: PROPOSED CONTOUR PROPOSED STORM SEWER PROPOSED SWALE EXISTING CONTOUR PROPOSED CURB & GUTTER PROPERTY BOUNDARY PROPOSED INLET A DESIGN POINT FLOW ARROW DRAINAGE BASIN LABEL DRAINAGE BASIN BOUNDARY PROPOSED SWALE SECTION 1 1 NOTES: 1. REFER TO THE PRELIMINARY DRAINAGE AND EROSION CONTROL REPORT FOR UNCOMMON DATED JULY 15, 2015 FOR ADDITIONAL INFORMATION. PROPOSED PERMEABLE PAVERS PROPOSED SUBDRAIN SD BENCHMARK FOR DRAINAGE REVIEW ONLY NOT FOR CONSTRUCTION PROJECT DATUM: NGVD88 City of Fort Collins Benchmark 06-00 On a catch basin at the northwest corner of Mulberry Street and College Avenue. ELEV. = 4993.85 City of Fort Collins Benchmark 29-97 Northeast corner of Mulberry St. and Whedbee Street, on a concrete traffic signal base. ELEV. = 4978.01 Basis of Bearings %DVLVRI%HDULQJVLVWKH:HVWOLQHRI%ORFNDVEHDULQJ1RUWKƒ  East (assumed bearing). HYDROLOGY SUMMARY C DRAINAGE SUMMARY TABLE DESIGN POINT BASIN ID TOTAL AREA (acres) C2 C100 2-yr Tc (min) 100-yr Tc (min) Q2 (cfs) Q100 (cfs) 1 1 0.13 0.78 0.98 5.0 5.0 0.3 1.3 2 2 0.62 0.95 1.00 5.0 5.0 1.7 6.2 3 3 0.05 0.40 0.50 5.0 5.0 0.1 0.2 the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 9, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Apr 22, 2011—Apr 28, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 9 VAULT ELEC CONTROL IRR CONTROL IRR T TELE VAULT ELEC ST ST ST W W E E E E W W T T FO FO E E E E E T T T T CTV CTV CTV CTV W W W W W FO FO FO FO G G G G G E E E SS E SS E SS E SS M H ELEC T VAULT CABLE S ELEC ELEC VAULT T ELEC VAULT ELEC VAULT ELEC CONTROL IRR CONTROL IRR T TELE VAULT ELEC ST ST ST DRAWN BY: SCALE: ISSUED: UNCOMMON EXHIBIT EXISTING & PROPOSED IMPERVIOUS AREAS ATC 1 in=60 ft JULY 15, 2015 1 ROOFTOP CONCRETE ASPHALT LANDSCAPE SURFACE AREA (SF) % IMPERV. IMPERV. AREA (SF) 5,032 2,508 24,468 1,716 100% 100% 100% 0% 0 TOTAL 33,724 TOTAL= 32,008 ROOFTOP CONCRETE ASPHALT PERMEABLE PAVERS SURFACE AREA (SF) % IMPERV. IMPERV. AREA (SF) 31,494 0 0 2,230 100% 100% 100% 22% TOTALS 33,724 TOTAL= 31,984 EXISTING PROPOSED 491 LANDSCAPE 0 0% 0 301 N. Howes Street, Suite 100 Fort Collins, Colorado 80521 N O R T H E RN PHONE: 970.221.4158 www.northernengineering.com 5,032 2,508 24,468 31,494 0 0 (min) 10-yr Tc (min) 100-yr Tc (min) 11No0.95 0.95 1.00 20 2.00% 1.0 1.0 0.7 229 0.40% 1.26 3.0 0 0.00% N/A N/A 5 5 5 22No0.95 0.95 1.00 20 2.00% 1.0 1.0 0.7 134 0.50% 1.41 1.6 0 0.00% N/A N/A 5 5 5 33No0.95 0.95 1.00 45 1.00% 1.9 1.9 1.3 215 1.00% 2.00 1.8 0 0.00% N/A N/A 5 5 5 DEVELOPED TIME OF CONCENTRATION COMPUTATIONS Gutter Flow Swale Flow Design Point Basin Overland Flow ATC July 1, 2015 Time of Concentration (Equation RO-4)  3 1 1 . 87 1 . 1 * S Ti C Cf L  