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HomeMy WebLinkAboutReports - Erosion Control - 03/29/2025 v L J L u N U L u L N VOA Switchgrass Erosion Control Report March 29, 2025 Owner/Developer: Doug Snyder Volunteers of America 2660 Larimer St Denver, CO 80205 Design Engineer: Ted Swan, PE Shopworks 301 W. 45th Ave Denver, CO 80216 Contractor/SWMP Administrator: Bob Thayer BC Builders, LLC 7108 S Alton Way E-1 Centennial, CO 80112 Ted Swan, PE 43903 S r1 C3 P LU tea F K Page 1 of 13 301 West 45th Avenue,Denver,CO 80216 303 433-4094 v ll u Table of Contents L L u l A. Project Description pg. 3 rg B. Potential Pollution Sources pg. 4 C. Control Measures pg. 7 D. Project Phasing pg. 8 E. Maintenance and Inspection Requirements pg. 8 F. Final Vegetation and Stabilization pg. 8 G. References pg. 9 H. Appendix pg. 10 S ri 0 P LLW C) r- H S Page 2 Of 13 '!'Avenue,Denver,CO 80216 303 433-4094 v L J A. Project Descriptionji L 1. Location L a. The 1.40 ac (as platted) VOA Switchgrass site (Site) at 3800 S Mason St is bounded by Mason Street on the west, commercial property on the east and south, and Mason Place residential property on the north. The property has been platted as Creger Plaza Third Replat Lot 2 Subdivision Filing No. 1, Lot 1, Blk 1. Please see vicinity map below: VICINITY MAP CREGER DR SITE 0 j J 7 N m w 2-1W O C7 c� a J x o Q C/) U COLBOARD DR Scale 1" = 300' b. The existing 1.4 acre site (as platted) is currently developed with an asphalt parking lot covering the entire site. The site slopes generally to the west at 1-2% to two existing inlets that convey storm water downstream to the storm main within Mason St. Geotechnical analysis has been performed and the soil is anticipated to be mostly comprised of type C and D clayey soils as supported by the NRCS soil data. I1 C PLij CD f Fi 5 Page 3 of 13 "'Avenue,Denver,CO 80216 303 433-4094 Groundwater was found at depths of 8+ ft in all borings. The NRCS soil map has been included in Appendix A.As shown on FEMA FIRM Panel O8O69CO987G in Appendix A,the site is not located in a FEMA floodplain. c. The proposed project will include the construction of a multifamily residential W Li building, parking lot and drive lanes on the 1.4 acre site. The site disturbance will L include the full 1.4 acres of the property as well as an additional 0.2 acres of the Mason St right of way. The initial phase of construction will involve placement of perimeter erosion control BMPs including rock socks along the Mason St sidewalk and curb socks within the Mason St gutter and then demo of the existing asphalt parking lot. It is anticipated that the staging area will be roughly 0.1 acres and located along the northern edge of the property. It is expected that soil will be imported into the site with an approximate net fill of 1500 yds. After demo is complete, then the site will be rough graded and the three extended detention basins will be graded in as temporary sediment basins for construction stormwater treatment. Diversion ditches will be graded in to route stormwater to the temp sediment basins. Following the completion of grading,the site will be excavated for building foundation and utilities will be constructed to connect to existing public infrastructure.After the utilities and building foundation have been constructed then the building vertical construction will begin. Finally,the last phase of construction will be site stabilization including paving operations and landscape construction. B. Potential Pollution Sources 1. All Disturbed and Stored Soils a. As the Site is demolished, graded and excavated, disturbed soil will be present onsite with the potential to be transported into Mason St and the downstream storm system. b. As noted, the site will have perimeter rock socks placed on the downhill Mason St side of the site as well as diversion ditches to convey construction stormwater to temporary sediment basins on the outskirts of the site. These measures should help reduce the potential for offsite sediment transport. 2. Vehicle Tracking of Sediments a. During grading and excavation activities, construction vehicles will collect sediment and soil on their tire treads and potentially transport to the Mason St Right of Way. b. Vehicular traffic will be limited to the northern entry during construction and a vehicle tracking control pad (VTC) will be installed to remove sediment and soil from tire treads. This will reduce the potential for transport into the Right of Way. Additionally, periodic street sweeping will be conducted to remove and sediment and soil from Mason St 3. Management of Contaminated Soils 0 F, LJJ CD r �-i S Page 4 of 13 "'Avenue,Denver,CO 80216 303 433-4094 a. Contaminated soils were not encountered on site during the geotechnical analysis Gi and are not expected to be an issue during construction. b. If contaminated soils are encountered during construction then State protocol will be followed for disposal. L L 4. Loading and Unloading Operations a. Material and Soil loading and unloading operations are anticipated to occur onsite. fu However, the material is anticipated to be standard construction materials. b. Loading and unloading operations will occur within the boundaries of the site. Materials are not anticipated to be contaminated or hazardous and the established boundary control will reduce the risk of materials spreading offsite. 5. Outdoor storage of construction materials, building materials, fertilizers and chemicals a. Outdoor storage of construction and other materials is anticipated to occur onsite prior to their use in building construction, landscaping and paving. b. Construction and other materials will be largely stored in the stabilized staging area. They will be elevated off the ground surface to prevent transport via storm runoff. In the event of a spill, MHFD protocol will be followed by the use of sandbags and earthen barriers to capture materials and dispose properly. 6. Bulk storage of materials a. Since the site is primarily covered in pavement currently and the site is anticipated to be an import site, bulk storage of materials and stockpiling is not expected to be necessary. b. If bulk storage of materials and stockpiling is required, specific perimeter controls including silt fence and rock socks will be placed directly around the storage/stockpile area. 7. Vehicle and Equipment Maintenance and Fueling a. Vehicle and equipment maintenance and fueling is anticipated to occur onsite during the course of construction. b. Vehicle and equipment maintenance and fueling will largely occur in the stabilized staging area. In the event of a spill, MHFD protocol will be followed by the use of sandbags and earthen barriers to capture materials and dispose properly. 8. Significant dust or particulate generating process a. Significant dust or particulate generating process is not anticipated to occur regularly onsite, but could occur during initial grading operations. b. Water trucks will be utilized to mitigate dust during grading operations.Areas outside the building footprint that are to remain unpaved and unplanted for over two weeks will be seeded and mulched to reduce dust from the site. 9. Routine maintenance activities involving fertilizers, pesticides, detergents, fuels, solvents and oils. a. Routine maintenance activities involving potentially hazardous chemicals is not anticipated to occur onsite regularly. S I1 0 P Uj CD f Fi S Page 5 of 13 Avenue,Denver,CO 80216 303 433-4094 b. If maintenance activities involving chemicals do occur onsite,they will be largely QJ conducted in the stabilized staging area. In the event of a spill, MHFD protocol will be followed by the use of sandbags and earthen barriers to capture materials and dispose properly. W U L 10. On site waste management practices a. On site waste management is anticipated to occur regularly during the course of fu construction. b. An outside waste management company will be responsible for waste disposal and waste facility maintenance. Both services will occur regularly on a schedule. 11. Concrete truck/equipment washing a. A concrete truck and other equipment including chutes is expected to be onsite regularly during the course of construction. b. A concrete washout area has been located in the erosion control plans and will be constructed in accordance with MHFD standard details. Maintenance and disposal will occur as needed per MHFD criteria. 12. Dedicated asphalt and concrete batch plants a. Considering the scale of the project, dedicated asphalt and concrete batch plants will not be necessary 13. Non-industrial waste sources such as worker trash and portable toilets a. On site waste management is anticipated to occur regularly during the course of construction. b. An outside waste management company will be responsible for waste disposal and waste facility maintenance. Both services will occur regularly on a schedule. 14. Saw Cutting and Grinding a. Saw Cutting and grinding of existing pavements is expected to occur regularly during the course of construction. b. Slurry from saw cutting and grinding is to be continuously vacuumed and stored onsite until it can be disposed of at designated facilities 15. Other non-stormwater discharges including construction dewatering a. Considering the low groundwater table and relatively low depth of excavation required for the project, construction dewatering is not anticipated to be necessary during the course of construction b. If local areas of higher groundwater are encountered, it will be pumped to an onsite basin and allowed to infiltrate. Page 6 of 13 301 vvLL L 45"'Avenue,Denver,CO 80216 303 433-4094 C. Construction Control Measures -the following BMPs are anticipated to be utilized Gi during the course of construction to reduce erosion and offsite sediment transport. See erosion control details plan for additional information. U 1. Rock Socks L a. Rock Socks will be utilized at the western perimeter of the site along the Mason St curb and gutter. Their purpose will be to reduce flows from the site into Mason St fu and trap sediment. Rock socks will be placed during the initial phase of erosion control and demo. They will remain until the site is stabilized at the end of construction. 2. Diversion Ditches a. Diversion Ditches will be used at the perimeter of the site to capture runoff from the construction site and convey to the Temporary Sediments ponds for water quality treatment. Diversion Ditches will be placed during the interim phase of erosion control when excavation and grading begin. They will remain until the site is paved in the final erosion control phase. 3. Check Dams a. Check Dams will be installed within the diversion ditches to slow the velocity of runoff within the ditch and allow sediment to fall out. Check Dams will be placed during the interim phase of erosion control when excavation and grading begin. They will remain until the site is paved in the final erosion control phase. 4. Temporary Sediment Ponds a. Temporary Sediment Ponds will capture and contain construction stormwater so that sediment and other pollutants can settle out before water is routed to the public storm system downstream. Temporary Sediment Ponds will be placed during the interim phase of erosion control when excavation and grading begin. They will remain until the site is paved in the final erosion control phase. 5. Vehicle Tracking Control a. Vehicle Tracking Control will be installed at the singe entry to the site at the NW corner. It will reduce sediment transport from construction traffic into the Mason St ROW.Vehicle Tracking Control will be placed during the initial phase of erosion control and demo. It will remain until the site is paved in the final erosion control phase. 6. Stabilized Staging Area a. A stabilized staging area will be located at the NE corner of the site and will contain trailers, wastewater facilities, and raised material storage and stacking pads. The Staging area will be out of the path of onsite storm runoff and will provide a place to store materials that will be out of the way of construction vehicles. The Staging Area will help to reduce material and chemical spills. The Stabilized Staging Area will be placed during the initial phase of erosion control and demo. It will remain until the site is paved in the final erosion control phase. 7. Inlet protection a. Inlet protection will be placed around onsite inlets to slow down construction runoff and allow sediment to settle out of stormwater before it is conveyed downstream to public storm sewer. The inlet protection will be placed during the initial phase of I`1 0 P LLY CD f Fi S Page 7 of 13 "'Avenue,Denver,CO 80216 303 433-4094 erosion control and demo. It will remain until the site is paved in the final erosion control phase. 8. Concrete Washout Area a. A concrete washout area will be provided onsite to contain the slurry from concrete L trucks and chutes. The area will collect concrete slurry and will then be disposed of L properly offsite. The Concrete Washout Area will be placed during the interim phase of erosion control. It will remain until concrete construction is no longer necessary rg in the final erosion control phase. 9. Seeding and Mulching a. Areas of the site outside of the building footprint that are to be disturbed and remain unpaved for more than 2 weeks will be seeded and mulched to stabilize soil and reduce sediment transport. The Seeding and Mulching will be placed during the final phase of erosion control to stabilize areas of the site that will not be paved or landscaped immediately. D. Project Phasing 1. The project will be completed in one phase. E. Maintenance and Inspection Requirements 1. All erosion control BMPs will be inspected weekly and after all storm events to ensure they are functioning properly. BMPs shall be replaced if they are determined to no longer be functioning at the same level as when they were initially installed. F. Final Vegetation and Stabilization 1. At the end of construction, all areas of the site that are not within the building footprint will be paved, landscaped in accordance with the project landscape plans or seeded and mulched in accordance with City Code, Section 12-160 through 12-162. Soil bed preparation and seed mixes will be prescribed within the landscape plans for the site. Disturbed areas to be seeded and mulched will be considered finally stabilized once plant life is visible at the surface. 2. The estimated timeline for stabilization of onsite disturbed areas is six weeks once the fall or spring growing season has been reached. 3. Sediment within all storm infrastructure onsite and the adjacent Mason St ROW will be removed to the greatest extent possible by the use of hydrovacuum at the end of construction. Removal will take place once final stabilization has been met onsite and before the last remaining BMPs have been removed ri o P SLY a cT H S Page 8 of 13 301 Ud L-15"'Avenue,Denver,CO 80216 303 433-4094 G. References 1. Fort Collins Stormwater Criteria Manual,Aurora, CO, December 2018. 2. Urban Storm Drainage Criteria Manual,volumes 1, 2, and 3, Urban Drainage and Flood L Control District,August 2018, September 2017, and January 2021 (respectively). L rg S ri o P SLY a CT H S Page 9 of 13 "'Avenue,Denver,CO 80216 303 433-4094 v 3 ll u 01 U L u l N Appendix A USGS Soil Survey FEMA FIRM Map ri 0 P U.J CD cT H S Page 10 of 13 301 v, '!'Avenue,Denver,CO 80216 303 433-4094 Hydrologic Soil Group—Larimer County Area,Colorado 3: 'v a 0 0 4932K 493270 493280 493290 4933W 493310 493320 49.3330 493340 493350 40°32'7"N Ir l I I I I 1 1 40°3Z 7"N gqq�ml w now" o I? W 1 �H o o A oo C V M m O O s a r it � m y not be valid at this scal 40°32'2"N W I 400 32 2 N 493260 493270 493280 411. 4973300 493310 493320 493330 493340 493350 3 3 Map Scale:1:619 if printed on A portrait(8.5"x 11")sheet. c Meters N ° 0 5 10 20 30 Feet 0 30 W 120 180 Map projection:Web Mercator Comer coordinates:WGS84 Edge tics:UTM Zone 13N WGS84 USDA Natural Resources Web Soil Survey 3/26/2025 Conservation Service National Cooperative Soil Survey Page 1 of 4 Hydrologic Soil Group—Larimer County Area,Colorado MAP LEGEND MAP INFORMATION Area of Interest(AOI) 0 C The soil surveys that comprise your AOI were mapped at Area of Interest(AOI) 0 CID 1:24,000. Soils © D Warning:Soil Map may not be valid at this scale. Soil Rating Polygons A Not rated or not available Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil F—] AID Water Features line placement.The maps do not show the small areas of Streams and Canals contrasting soils that could have been shown at a more detailed 0 B scale. Transportation B/D *.. Rails Please rely on the bar scale on each map sheet for map 0 C measurements. � Interstate Highways 0 C/D US Routes Source of Map: Natural Resources Conservation Service Web Soil Survey URL: 0 D Major Roads Coordinate System: Web Mercator(EPSG:3857) 0 Not rated or not available Local Roads Maps from the Web Soil Survey are based on the Web Mercator Soil Rating Lines Background projection,which preserves direction and shape but distorts q distance and area.A projection that preserves area,such as the Aerial Photography Albers equal-area conic projection,should be used if more .-.. AID accurate calculations of distance or area are required. ++� B This product is generated from the USDA-NRCS certified data as ti B/D of the version date(s)listed below. C Soil Survey Area: Larimer County Area,Colorado Survey Area Data: Version 19,Aug 29,2024 r.i CID Soil map units are labeled(as space allows)for map scales ... D 1:50,000 or larger. Not rated or not available Date(s)aerial images were photographed: Jul 2,2021—Aug 25, Soil Rating Points 2021 p A The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background E3 AID imagery displayed on these maps.As a result,some minor B shifting of map unit boundaries may be evident. B/D USDA Natural Resources Web Soil Survey 3/26/2025 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group—Larimer County Area,Colorado Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 76 Nunn clay loam,wet, 1 C 0.5 27.7% to 3 percent slopes 90 Renohill clay loam,3 to D 0.1 7.2% 9 percent slopes 136 Water 1.2 65.1% Totals for Area of Interest 1.9 100.0% Description 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. 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. USDA Natural Resources Web Soil Survey 3/26/2025 Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group—Larimer County Area,Colorado Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher USDA Natural Resources Web Soil Survey 3/26/2025 Conservation Service National Cooperative Soil Survey Page 4 of 4 NOTES TO USERS FLOODING EFFECTS FROM LEGEND SPRING CREEK This map is for use in administering the National Flood Insurance Program. It PROFILE BASE LINE SPECIAL FLOOD HAZARD AREAS (SFHAs) SUBJECT TO does not necessarily identify all areas subject to flooding, particularly from local ` INUNDATION BY THE 1% ANNUAL CHANCE FLOOD drainage sources of small size. The community ma repository should be 3115000 FT Drop Structure LL0518 Bridge SPRING PARK DRIVE 3120000 FT g Y p p y 105°05'37.5" g JOINS PANEL 0979 105°03'45.0" The 1% annual chance flood (100-year flood), also known as the base flood, is the flood ,..,, N consulted for possible updated or additional flood hazard information. .. 40133'45.0" that has a 1% chance of being equaled or exceeded in any given year. The Special 40°33 45.0 ::::.::::.::::.;:.:.:. . ......... ...... ...... .... ... .... ...... Bridge e .. ER o K R\v Flood Hazard rd Area is the area subject to flooding b the 1 annual chance flood Are as E T0 obtain more detailed information In areas where Base Flood Elevations ::.::.:,.y,..:..... .:..:. :..:.:.:.:.:.:.:..: .... .:...:.:.:..:.:. .:.:.:....:.:.:.:.:.:. .:.:.:..... .:.:.:.:....:.:.:.:... .:.:.:.:.:. .:.:.:.:..:.:.:..:: : ... .:::.... ...... ..:.: :.:. :. :. . :.. .:.:.:..:.:...:.:..:. of Special Flood Hazard Include Zones A AE AH AO, AR A99 V and VE. The Base F.... >.o :•:»:'. :.: _::::.::::.: .:.:::.>':::.::.;•:::.:::::..:: >'::.::.::: ;:: - :.::.;:.;:::»:::::>:.;:.:':»::.;':>:.;:.;' . ': ::.:::.>:.::. ::.>:.:::.:<.::.::::.<»:.>::: -surface elevation ofthe 1/ annualchance flo od.Elevation is the waterBFEsand/or floodways have been determined users are encouraged to consult WAY DO O V lC 9 the Flood Profiles and Floodway Data and/or Summary y of Stillwater Elevations cr, SP In g E ZONE A No Base Flood Elevations determined. tables contained within the Flood Insurance Study (FIS) report that accompanies N rn U ZONE AE ..: ...:.: ..... ............ ...... ...... ...... ...... ...... .... «:<:::<:>:::<:>' o >i Base Flood Elevations determined. co d. v w Creek cn this FIRM. r should aware h BFE shown n h FIRM represent 0 t s Usessoud bea ae that s so o to = � Cn m rn HI L O L c7 a- rtn r k O m S Creek v Z NE AH ZONE o Flood depths of 1 to 3 feet (usually areas of ondin Base Flood - z ,rounded whole foot elevations. These BFEs are Intended for flood Insurance P ( Y P 9) A G> c m O AE Elevationsrmin U determined.o m ratingpurposes only and should not be used as the sole source of flood D N w P P Y o > Ro a u, D �� +� m 44 OOOm M. CoONE AO elevation information. Accordingly, flood elevation data resented in the FIS «< ::o:::. o,q Flood depths of i to 3 feet (usually sheet flow on sloping terrain); p n � 90 N p ( Y p 9 ) report should be utilized in conjunction with the FIRM for purposes of m m average depths determined. For areas of alluvial fan flooding, velocities construction and/or floodplain management. i also determined. Q Q DARTMO JQ� DARTMOUTH M TRF\L ZONE AR Special Flood Hazard Area formerly protected from the 1% annual Coastal Base Flood Elevations shown on this map apply only landward GT o chance flood by a flood control system that was subsequently of 0.0' North American Vertical Datum of 1988 (NAVD 88). Users of this Q y TRP\� U decertified. Zone AR indicates that the former flood control system is FIRM should be aware that coastal flood elevations are also provided in the IRUTGERS AVENUE o being restored to provide protection from the 1% annual chance or Summary of Stillwater Elevations table in the Flood Insurance Study report w w a greater flood. for this jurisdiction. Elevations shown in the Summary of Stillwater Elevations > > — ZONE A99 Area to be protected from 1% annual chance flood by a Federal table should be used for construction and/or floodplain management purposes o c a OUKE> LANE S°JPP� j flooddete netection system under construction; no Base Flood Elevations when they are higher than the elevations shown on this FIRM. d. Z DUKE � O ZONE V Coastal flood zone with velocity hazard (wave action); no Base Flood Boundaries of the floodways were computed at cross sections and interpolated Q ° ° Elevations determined. between cross sections. The floodways were based on hydraulic considerations a 'o COLUMBIA ROAD Z ZONE VE Coastal flood zone with velocity hazard (wave action); Base Flood with regard to requirements of the National Flood Insurance Program. Floodway Q � J LU o Elevations determined. widths and other pertinent floodway data are provided in the Flood Insurance 23 rimer County Canal No. 2 m ' LU 0 24 in Study report for this jurisdiction. o w co m $ Q FLOODWAY AREAS IN ZONE AE WOR ,APO Certain areas not in Special Flood Hazard Areas may be protected by flood G�� Q J Do CORNELL AVENUE The floodway is the channel of a stream plus any adjacent floodplain areas that must be THINGTpN control structures. Refer to Section 2.4 "Flood Protection Measures" of -ALE WAY $ w CAMBRIDG kept free of encroachment so that the 1% annual chance flood can be carried without the Flood Insurance Study report for information on flood control structures o a U) o E substantial increases in flood heights. for this jurisdiction. 90 ° _ ~n DRIVE w OTHER FLOOD AREAS The projection used in the preparation of this map was Colorado State 9 w Nv2 w V ANDFRg, ZONE X Areas of 0.z% annual chance flood; areas of 1% annual chance flood W Plane north zone (FIPSZONE 0501).The horizontal datum was NAD83, D T > cT N z o o with average depths of less than 1 foot or with drainage areas less than GRS1980 spheroid. Differences in datum, spheroid, projection or State Plane 9 a c 9 N couRT F 1 /o square mile; and areas protected by levees from 1 annual chance y > O AVENUE n w o zones used in the production of FIRMS for adjacent jurisdictions may result in ° F °w Cr slight positional differences in map features across jurisdiction boundaries. o eR 1­_ w flood. am These differences do not affect the accuracy of the FIRM. ¢ „ QUEENS a 0 OTHER AREAS } O COURT Flood elevations on this map are referenced to the North American Vertical �° ZONE X Areas determined to be outside the 0.2% annual chance floodplain. G PRINCETON ROAD Datum of 1988. These flood elevations must be compared to structure and < + w� ground elevations referenced to the same vertical datum. For information 1445000 FT `� j ZONED Areas in which flood hazards are undetermined, but possible. regarding conversion between the National Geodetic Vertical Datum of 1929 0 0 and the North American Vertical Datum of 1988, visit the National Geodetic P°P° < ® COASTAL BARRIER RESOURCES SYSTEM (CBRS) AREAS Survey website at http://www.ngs.noaa.gov/ or contact the National Geodetic PRINCETON BAYLOR STREET Survey at the following address: OTHERWISE PROTECTED AREAS (OPAs) NGS Information Services XLL1032 o CBRS areas and OPAs are normally located within or adjacent to Special Flood Hazard Areas. NOAA, N/NGS12 DRAKE ROAD DRAKE ROAD National Geodetic Survey WD � F oo pain boundary SSMC-3, #9202 m = o Floodway boundary 1315 East-West Highway D DRIVE y M z O Silver Spring, MD 20910-3282 `-o �LU < (nn a > " 44 000m - - Zone D boundary o = a o ~ 0 89 N CBRS and OPA boundary To obtain current elevation, description, and/or location information for bench marks o J �, zFWINCHESTER DRIVE E Boundary dividing Special Flood Hazard Areas of different o w \V rY 9 Pe shown on this map, please contact the Information Services Branch of the � o a � oR m 0 w O O THUNDERBIRD o Base Flood Elevations, flood depths or flood velocities. National Geodetic Surveyat 301 713-3242 or visit its website at Q w U THUNDERBIRD DRIVE m e z O HEATH Cc http://www.ngs.noaa.gov/. > � STREET LU a o o ^^^^^' 513 Base Flood Elevation line and value; elevation in feet* Base map information on this FIRM was provided by the Larimer County GIS and POWDERHORN DRIVE o W RI w m N w � ° (EL 987) Base Flood Elevation value where uniform within zone; Mapping Department. Additional input was provided b the City of Fort Collins > m O CIfFR ��E o ALLE STRAGHAN DRIVE w elevation in feet* pp g p p P Y Y m 9 a DP a w m > Geographic Information Services Division. These data are current as of 2010. o z ° z TREET o w o *Referenced to the North American Vertical Datum of 1988 (NAVD 88) O w p S U 0 0 DRitr c� a s Z A A Cross section line z F z ¢ MAE o This map reflects more detailed and up-to-date stream channel configurations Q�� ��� o than those shown on the previous FIRM for this jurisdiction. The floodplains PQP o °P w RUT� STR. ALEXAND 23 ------- 23 Transect line Z Cc and floodways that were transferred from the previous FIRM may have been °� w Geographic coordinates referenced to the North American adjusted to conform to these new stream channel configurations. As a o MORSMPN �, o w a 97`07'30",32°22�30° Datum of 1983 NAD 83 z w CLAIR ROAD OXFORD LANE m O ( ) result, the Flood Profiles and Floodway Data tables in the Flood Insurance � Roc ° J a o a Ky m O Z �� o o a2750oomN 1000-meter Universal Transverse Mercator grid ticks,zone 13 Study report (which contains authoritative hydraulic data) may reflect stream o ANNAg� ° � J channel distances that differ from what is shown on this map. ° MO1NTAIN WAS °°�� NIGHTHAWK DRI�F U_ s� LU 5000-foot grid ticks: Colorado State Plane coordinate 6000000 FT ra w y OOR DRIVE Q system,north zone(FIPSZONE 0501),Lambert Conformal Conic Corporate limits shown on this map are based on the best data available o o w <9 w a- CD at the time of publication. Because changes due to annexations or de-annexations 00 ° Z o �'o W U) may have occurred after this map was published, map users should contact o ° o Z > o z Bench mark see explanation in Notes to users section of CC G z z m DX5510 ( P appropriate community officials to verify current corporate limit locations. Lu o �m N o New Mercer `� ° �P� y v OW ROAD X this FIRM panel) Q " W m Irrigation Canal °F L� N sWALL M1.5 Please refer to the separately printed Map Index for an overview map of the � m °o Z z L 2,� 2G W • River Mile county showing the layout of map panels;community map repository addresses; cn 0 a o ¢ 0 ° o Z_ a a o ° MAP REPOSITORIES and a Listing of Communities table containing National Flood Insurance Program J a w � Z o O a a > z 9G Refer to Map Repositories list on Map Index dates for each community as well as a listing of the panels on which each m O w community is located. w o °PD U_ m m > AqR� M P L� EFFECTIVE DATE OF COUNTYWIDE For information and questions about this map, available products associated with this U' SWALLOW 25 o m g FLOOD INSURANCE RATE MAP w FIRM including historic versions of this FIRM, how to order products or the National Z 26 w � 5 a ° December 19,2006 w J cn 3 � EFFECTIVE DATE(S)OF REVISION(S)TO THIS PANEL Flood Insurance Program in general, please call the FEMA Map Information eXchange ZUNI a w a 3 cn DRIVE May 2,2012-to change Special Flood Hazard Areas, to change floodway, to reflect updated at 1-877-FEMA-MAP (1�377-336-2627) or visit the FEMA Map Service Center website m >_ w �i topographic information, to change Base Flood Elevations,and to incorporate previously issued w w Letters of Map Revision. at http://msc.fema.gov.Available products may include previously issued Letters of Map a Change, a Flood Insurance Study Report, and/or digital versions of this map. Many of Y ° a Larimer County a � these products can be ordered or obtained directly from the website. Users may a Quo � Q determine the current map date for each FIRM panel by visiting the FEMA Map °�° m o Canal No. 2 ¢ Service Center website or by calling the FEMA Map Information eXchange. ��� °� cc W w For community map revision history prior to countywide mapping,refer to the Community E O� elG 0 9 Map History table located in the Flood Insurance Study report for this jurisdiction. oF Y �(i�e/9 FOOTHILLS PARKWN Q = o CT. NOTE: MAP AREA SHOWN ON THIS PANEL IS LOCATED To determine if flood insurance is available in this community, contact your insurance w Fs WITHIN TOWNSHIP 7 NORTH, RANGE 69 WEST. z ° agent or call the National Flood Insurance Program at 1-800-638-6620. J 9 44 88 OOOm N U, J� � o IGUNNISON DP\ Off\ -9�FNUE PLOWMAN WAY Pt } AN 3� MAP SCALE 1" = 500' z0 C°G LL0523 CITY OF FORT COLLINS 80LTZ DRIVE 250 0 500 1000 FEET 00 JUSTICE DR/V, �� ° 080102 METERS 150 0 150 300 O DRIVE O \VE ��ij Z4, \� Lu D MONROE R/G� SYDNEY DRIVE w °FIVE PANEL 0987G 1440000 FT RIVA J°��s oP RIDGLAN < 0 0 0 o oQ O°�Ft� o �Q D z w P OPv 0- LU o m a Z z FIRM a O,�9y9C °P,vz m a c m FLOOD INSURANCE RATE MAP 0 J RIDGE QQQ�� o� ��k o KINGSTON DRIVE ® LARIMER COUNTY, �o� Z Ni1� «y 3: HORSETOOTH ROAD Q�N DRIFTCpURT �PRREN m COLORADO D0 X a O gNDING AVENUE w W LL0525 w a = AND INCORPORATED AREAS ARBOR u~i = w j a A DR\VE a Z m s s/AR PANEL 987 OF 1420 BONITA AVENUE O F- z yy n Q ygVEN w Z O �. ROAD ° > Q = ¢ Y A7pER PO�� (SEE MAP INDEX FOR FIRM PANEL LAYOUT) Q F CREGER DRIVE o 0290 0 o WAY w J w LEEWgRD COURT m CONTAINS: 0 ° AVENUEz WALDEN o �oz o z COMMUNITY NUMBER PANEL SUFFIX U G O g cn m FORT COLLINS,CITY OF 080102 0987 G 9< 0 02 (DBOWLINE CT CO o a ¢ z ~ DENNISON J w 35 0 BOCKMAN DRIVE Sot 36 w l� m WAVENUE z tq� LLLLJJ 729 �O� O COLBOARD DRIVE to 4487000m N 6gsy P�� w q<eION � G sT 9F��0 > Notice to User: The Map Number shown below should be o j �Q BOARDWALK s PAL used when placing map orders; the Community Number shown ca z ORI� �y of above should be used on insurance applications for the subject SAIL LANE � community. MARBLE DRIVE F�o� o9G �pti4A��t�t,o MAP NUMBER F BENTHAVEN SSTIR. Q �ETON Cp 08069CO987G 40131'52.5" �P 40131'52.5" �O �+' JOINS PANEL 1000 105°03'45.0" � 04 MAP REVISED 105105'37.5" 493000m E 494000m E LAND SEC. MAY 2, 2012 Federal Emergency Management Agency v 3 ll u 01 U L u l N Appendix B Erosion Control Escrow Calculation Page 11 of 13 301 v, '!'Avenue,Denver,CO 80216 303 433-4094 Example Erosion and Sediment Control Escrow/Security Calculation for The City of Fort Collins Project: Switchgrass Crossing Disturbed Acres: 1.60 - BMP Amount Estimated Unit Total EROSION CONTROL BMPs Units Quantity Price Price Rock Socks (RS) L.F. 275 $3.00 $825.00 Inlet Protection (IP) EA 3 $500.00 $1,500.00 Concrete Washout (CW) EA 1 $1,000.00 $1,000.00 Vehicle Tracking Control (VTC) S.F 921 $8.00 $7,368.00 Stabilized Staging Area (SSA) S.F. 3212 $3.00 $9,636.00 Temporary Sediment Basin (TSB) EA 3 $1,000.00 $3,000.00 Seeding and Mulching S.F. 10,125 $2.50 $25,312.50 ...etc... $0.00 (add all other BMPs for the site in this list) Sub-Total: $48,641.50 1.5 x Sub-Total: $72,962.25 Amount of security: $72,962.25 Reseeding Amount Total Acres x Price/acre: $14,400.00 Unit Price of Seeding per acre: $9,000.00 Sub-Total: $14,400.00 1.5 x Sub-Total: $21,600.00 Amount to Re-seed: $21,600.00 Miniumum Escrow Amount Minimum escrow amount: $3,000.00 Final Escrow Amount Erosion Control Escrow: $72,962.25 Fields in yellow should be amended for this project. "The amount of the security must be based on one and one-half times the estimate of the cost to install the approved measures,or one and one-half tunes the cost to re-vegetate the disturbed land to dry land grasses based upon unit cost determined by the City's Annual Revegetation and Stabilization Bid, whichever is greater.In no instance,will the amount of security be less than one thousand five hundred dollars($1,500)for residential development or three thousand dollars($3,000)for commercial development" 4/7/2025 9:07 AM https://shopworksarc.sharepoint.com/sites/Server/Projects/24046 VOA Fort Collins Mason/Design/Civil/Erosion Control/Calculations/Example_Escrow