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Home My WebLink AboutGrading Plans - 05/18/2020 (3)Accepted 5/18/2020 WL , � ,, �� \ � ;� � � !�' ��J<��' t� �''` � _ - _ _ _%' % � , ,: v�--- � � ' � • , I► � ■ � November 22, 2019 Stormwater Engineering & Development Review Division City of Fort Collins Utilities 700 Wood Street Fort Collins, Colorado 80522 KEEFE CIVIL, LLC 825 Union Street Golden, Colorado 80401 (970) 215-6808 Keefe Civil Project Number: 2019-024 RE: 5425 South County Road 7 Drainage and Erosion Control Memo Parcel # 8604000020 To Whoin it May Concern: The purpose of this letter is to describe the proposed site improveinents and potential drainage impacts at 5425 South Counry Road 7(Appendix A). The 5.00 acre project site is a developed residential lot with established landscaping and pasture land located on the west side of South County Road 7 in Fort Collins, Colorado between Kechter Road and Big Dipper Drive. Prior to recent deinolition activities completed under a separate permit, the site had a two-story house, several outbuildings, and a detached garage. The lot is bound by existing residential properties to the north and south, the Willow Brook Subdivision to the west, and South County Road 7 right-of-way on the east. The majority of the site's soils consist of Nunn clay loam and a small percentage of Fort Collins loam per the NRCS Soil Survey of Larimer County (AppendiX B). Historically, site stormwater has drained with gentle slopes from the west to the east into the South County Road 7 borrow ditch and is conveyed underneath South County Road 7 north of the site's driveway via two 12"Xl 8" elliptical pipes. There is a localized low point north of the previous house's location, where the stormwater either infiltrates into pasture land and/or overtops the property boundary, flowing into the borrow ditch. Per the flood insurance rate map (Appendix C), the lot is located within Zone X. Zone X is defined as an area of minimal flood hazard and does not have a base flood elevation associated with it. The proposed site iinprovements include a two-story house with finished basement, oversized garage, kennel area, and a 16-foot concrete driveway. The existing detached garage will remain. In the future, the property owner may further develop the lot with a pavilion, pool, and landscape pavers. These future improvements have been included in site drainage calculations. The proposed drainage patterns will remain consistent with the e�sting conditions and will not result in concentrated flows leaving the property. The total impervious area will increase 17,015 sf, which is an 8% increase for the site. : V� �� Q� D3 � � r%� Q� O� �i� 03 CJ� V� D3 D 0� Q� �%3 Q� G�3 Q� G� D� Q� C%3 , e d d d a d d d d d d d a d d d d d d d d d d d d C a a G Q Q q G Q G Q G Q G�G G G G G a a Q q G G G C �°c��°c°d°a°o°c�o°Q°c°�°c°�d�°Q°�°c°c°c c°v°o°aaan�� A�As��G�G��,AGJAG�G��A�G'AAAA�AG�G.>G 5425 South CR 7 Drainage and Erosion Control Memo Keefe Civil Pi�oject No.: 2019-024 Page 2 of 2 November 22, 2019 Historic Adjusted Adjusted Change in Hardscape or Hard Area A Historic Developed Developed Impervious Surface s Area A s Area A s Area A s Area s Asphalt, Concrete 940 940 8,940 8,940 Rooftop 3,981 3,981 8,225 8,225 Pavers (40%) 0 0 5,015 2,006 Gravel (40%) 1,350 540 1,106 442 Total Impervious Area 6,271 5,461 23,286 19,613 17,015 The composite runoff coefficient and drainage basin runoff calculations for the historic and developed site are included in the enclosed tables (Exhibit D). Using the Fort Collins Stormwater Criteria Manual, the proposed stormwater runoff will increase slightly at the site. 2-year 10-year 100-year Basin A Historic Runoff 1.16 cfs l.99 cfs 5.34 cfs Basin A Developed Runoff 1.50 cfs 2.55 cfs 6.88 cfs Sased on the enclosed design, it is my professional opinion the additional runoff generated by these site improvements will not cause adverse impacts to downstream private properties. I herby attest that this letter for the final drainage design for the 5425 South County Road 7 was prepared by me or under my direct supervision, in accordance with the provisions of the Fort Collins Stormwater Criteria Manual. I understand that the City of Fort Collins does not and will not assume liability for drainage facilities designed by others. Erosion Control Measures The structural practices for the site will consist mainly of silt fence, vehicle tracicing control pad, and concrete washout area. The locations of these structural practices are shown in Appendix A. The corresponding construction control measures fact sheets are included in Appendix E. The anticipated disturbed area is estimated at 0.96 acre. The City of Fort Collins erosion and sediment control escrow calculations for the site are included in Appendix F. After site iinprovements have been completed, all disturbed areas shall be seeded with approved dryland native seed mix or landscaped by the home owner. Thank you for the opportunity to submit this drainage and erosion control meino. Please do not hesitate to reach out to me if you have any questions or coinments regai•ding the above iteins. (970) 215-6808 or meg@keefecivil.com _�� Best regards, Megan L. Keefe, PE / Manager Keefe Civil, LLC � ��PDO L1�F2 ��'��N•�•��sFO . � cc . : �� mt i 39378 i - IDISf.allysionetl�yMe5s / 1� Rea ee , � ',�...�11�_—'this _ einlefr��t�+!'Q 1� ` �2o'9e �� v ( ^FSS�ONAL.ENG�� Enclosures Cc: Steve Spanjer, Spanjer Hoines Dana Spanjer, Spanjer Homes � V� �� Q� G 13 V� D3 D 0� Q� V3 9� G'3 q� G� D� Q� t73 � e e e a e` a e- e a e� e" e a a e e a a a a e e a a a c a a a v v v a a a a a a a a a a a v a a a v a v a c �°c��°c°d°a°o°c�o°Q°c°�°c°�d�°Q°�°c°c°c c°v°o°aaan�� A�As��G�G��,AGJAG�G��A�G'AAAA�AG�G.>G i i �) / / �'� I � � � I � - �,��n. �� N �_ �,�.os�A��. li M � � � a�� < �o,orz i �ER�E�N_r A��n �tM�_N� � �I ��'—�� \ _ \ \ � � II I � � � 533 OU � IY Ii0A0 '1 E Eq u p I EXST. p 05pw00�016 L o^ rvE lo aE uoF w.rE Fwrn. I I li - � - - _ _ - ( � ) �` eb'i '�'a�-/' 1 �: a I I . - -c- -�e � Tlj "y.,�" ',� —_— / �I I , 1.4 r/ .i�4� I .��'�` �A`- � �.,^7 �.y �Mrts ulLnrGSEM y�-�}�- I I I I � � � � ,.�N�� lEy I I II+' II� I I i � ^�,� _ d _ __- . 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F�v�._ „� gp s �.,kP,� . �,a. w..o-. ,_��,on � �/�'Cl VEhIC_F TRACNNG CO�iROI. � -s�� pg . rRMANery. sFru.v, � cwn coNCAr,=wn��o�.-A-..A I � III � �PE w, FE= i i li i�F,..�a3�< ��a PP� w� �s ��- e.s� e . PP. w/ rea �li � t � � II �� . ,o' �awr w..er��mwk o..me.+ �ehM.eo...er.e x�,v..e.. �.«•1�1 nrta.(M w.Nl �.m�1a1 �uldl . .. . . .. . . ;':� 4su � fm� �.�..a.. J J � 0 JF� Uyomw woz1Ow Y��m� � 1� 1� 1� `� � � ¢ O � � U � O � v � 20F2 � Soil Map—�arimer County Area, Colorado � o (5425 South County Road 7) o 0 0 a��o as9n� asa�Fo assno ass�so as9eio as�o a�o as�o a�so as��o a�o 40° 30' 41" N — I. � I� I I, I. ,! I I � � . . I -�� I ,.� 40° 30' 41" N � I � ' �'�� ' t � � ,� � � , , � � `��i �- - -- - � - -�� ,� . �,.� : _ � i � ` .e !�"�_,�r,�...�.. ' � � ' I � . � �� ;� , �_�� _M: �. _ _ `q � � __ � � , . , .. � ;� - - . � _ , i � ' � ,� . � • �-� .,� � � �� , �� ,� . � ,��: '� �,�� `; ; . , ; �`� �-� �' . _ -� � � � : +; :� _� � '"�� :�� -��. � � ; �'�. � �� .� �I � `�- ; - ;, I� . a4 � �� : ,� -�� t. � ,,,; � ;; �.�� - - . � �-_ _� . ,� �'�. _ ` '� � , t �� :. �'` � ' �i 'ti r� :Sr.�_F _.,.S�w•. + _ , .— �: � i �� ri �� I � .. . ��"4rr ��' �'�� ' ��f � �ir; �P. � I ��1� � �� "� - ,�y,,.�.,� _ . ,_..��,�r, _,t,i�. i � ��1_"� ��'�ar-_�2. --- -. _ -_ . � 5�� - ` ��:rk., R �-�� .u_ � t � 'j . I �i �,� . � �� _•T� ��. � ��l�j'�i�� . � . � . ��: �' I � 'i.;� � � � � . ~ " �' '� V' ' _ r + ,� i _ ,� L . � — Soil�Map niay not I�e valid �t this sc�le. � — � �, _ �' ` � •� i - � T; — . � 40° 30' 36�� N ;. I a� � _ I _ . I, I , _ . ,I. . , i -- I � . - _ � -.� - _ _ _ —� I� _ I . _ _ I �. l. � �o �, �„ N 499710 499730 4937E0 499T/0 49JRJ0 49�10 49�30 � 499670 4�890 499310 499�0 � 3 fV o Map Scale: 1:1,080 if printed on A landscape (11" x 8.5") sheet � ., N Meters � 0 15 30 60 90 � Feet 0 50 100 20D 300 Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 uSDn Natural Resources Web Soil Survey 11/22/2019 � Conservation Service National Cooperative Soil Survey Page 1 of 3 Soil Map—�arimer County Area, Colorado (5425 South County Road 7) MAPLEGEND Area of Interest (A01) Area of Interest (AOI) Soils Soil Map Unit Polygo�s . e 5oil Map Unit Lines � Soil Map Unit Points Special Point Features V Blowout � Borrow Pit � Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow _ Marsh or swamp - Mine or Quarry Misceilaneous 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 . Speciai Line Features Water Features Streams and Canals Trensportation � Rails ti Interstate Highways US Routes Major Roads Local Roads Background � Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System� Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 14, Sep 13, 2019 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 11, 2018—Aug 12, 2018 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. us�n Natural Resources Web Soil Survey 11/22/2019 � Conservation Service National Cooperative Soil Survey Page 2 of 3 Soil Map—Larimer County Area, Colorado 5425 South County Road 7 Map Unit Legend Map Unit Symbol 35 73 74 Totals for Area of Interest Map Unit Name Fort Collins loam, 0 to 3 percent slopes Nunn clay loam, 0 to 1 percent slopes Nunn clay loam, 1 to 3 percent slopes Acres in AOI 0.1 2.8 2.0 4.9 Percent of AOI 2.9% 56.7% 40.4% 100.0% USD� Natural Resources Web Soil Survey 11/22/2019 � Conservation Service National Cooperative Soil Survey Page 3 of 3 National Flood Hazard Layer FIRMette �: FEMA 40°30'57.77"N � � r .� �' � ��a_. � 4 . � . _ � • i . w 1 � , � o '' � '�� . ��1 •" � (� �s_ , '1 I I I _I_l� I � �' o M � 1 �.�f � ` �'w� I ; � ` ♦ �r �`��* � � , �/�� ` � � �� I �y,� � , � f.`� � � � 4� I � • � � t' +r[ :- '�'^��'w.�`� r.• r •.� r � i � Vi Legend SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT Without Base Flood Elevation (BFE) Zone A. V A99 SPECIAL FLOOD With BFE or Depth zone ne. ao. aH ve nR HAZARD AREAS Regulatory Fioodway OTHER AREAS OF FIOOD HAZARD ��" ��'� ' A � � � I' - � , t,j ' � � _.....�� -•. M � �, .1 • i '� ' , :.�t', ,, >C�� :�H', � • r � . �� `, f . , r�'" ' ' � i,. . �, `, . � � J� �.�i� � ��:�.�, ,.�' �,,� , ...... � � F a "If`�� l'I �I:f •'l�Lli`d��' ...aa� .�,� \ _ .� ' ;, ' "� J w. i i i i li;i� � . . .�i-. �r:=.� ' � � � � L{afJIR �t 4�8-0580P � � � � � �;� ��` • � � -� eff �Z�1`�:Zt)1�� ' 4� � � � � _ s'] t � � r ,� ,.,, +�Fi� �i � �. 'i 11f.1�L�FL� �_,,�,.H�,-:;,f� �� , i� i , - , �I� �� '� � i��i i � ( �� • ��, � �: �4 T.�'� '' ��I � � � `� : � C t � f s." _ l _ . I . f f � �' I . � � f � � I � ' f,,.�! � I � +'/� r � � ' � �' '`r �� •� i •�. � p ► � �i . _ r ^� : . _� � .� y � � � � � �; � � .� ��'" � ` • •—.. `'� �` ,� ` , ' � • � � � . . .,�-�. y 1, � � ,�� F, _ . � � �. � _.��- .:i - � � ��. ' � �� _.S � ' � '��1 i� � �; � Y � � ��.n � Yi � � A► • • I • • l � � �i1�� • r w � � '. �'� , � '� �i',�,' ,�:�, , � -ti- . � ^. . �� y�� ... � _ � � "� '. —s' ,. �t�\. v.....�s. .. { i�.. ��. � � ` �1 L� �� f 0 . _ ' � 'F ' Feet 0 250 500 1,000 1,500 2,000 1:6,000 ; �� . , �� ' ;.,. �� ; k.x i. '�=,�� I'� � � �, � Or�trioimagery. � �� ' .J 0 A u; � �' , I l a A A _ 2 ��"9` � 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mile zo"<- x - Future Conditions 1%Annual � Chance Flood Hazard zo�,e x Area with Reduced Flood Risk due to Levee. See Notes. zo�,e x Area with Flood Risk due to Leveezooe o NO SCREEN Area of Minimal Flood Hazard zo�,<� x 0 Effective LOMRs OTHER AREAS Area of Undetermined Flood Hazard zo�,� o GENERAL '--' Channel, Culvert, or Storm Sewer STRUCTURES i i i i i i i Levee, Dike, or Floodwall B 2°'Z Cross Sections with 1%Annual Chance ��5 Water Surface Elevation 0- - - Coastal Transect �,., Base Flood Elevation Line (BFE) Limit of Study Jurisdiction Boundary --- --- Coastal Transect Baseline OTHER _ - profiie Baseline FEATURES i Hydrographic Feature MAP PANELS � Digital Data Available N No Digital Data Available � Unmapped The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 11i20j2019 at 5:37:12 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Composite Runoff Coefficient Calculations 5425 South County Road 7, Fort Collins, CO �Ic- �:i, I , :1. Equation 5-2 Where: C= Composite Runoff Coefficient C, = Runoff Coefficient for Specific Area (A,�, dimensionless A, = Area of Surface with Runoff Coefficient of C„ acres or square feet n= Number of different surfaces to be considered A. = Total Area over which C is applicable, acres or square feet Historic Drainage Basin A Developed Drainage Basin A Runoff Minor (2- and 10-yr) Major (100-yr) Minor (2- and 10-yr) Major (100-yr) Surface Type Coefficientsl Area (sf) Composite CZ Composite C3 Area (sf) Composite Cz Composite C3 Hardscape or Hard Surface Asphalt, Concrete 0.95 940 8,940 Rooftop 0.95 3,981 8,Z25 Pavers 0.50 0 5,015 Gravel 0.50 2,700 2,765 Totaltmpervious Area 7,621 24,945 Landscape or Pervious Surface Lawns, Clayey Soil, Flat Slope < 2% 0.20 210,176 192,852 Total Drainage Basin A 217,797 0.22 0.28 217,797 0.27 0.34 Notes: 1. Runoff coefficients per Fort Collins Stormwater Criteria Manual Table 3.2-2. 2. Composite runoff coefficient per Fort Collins Stormwater Criteria Manual Equation 5-1. 3. Frequency adjustment factor per Fort Collins Stormwater Criteria Manual Table 3.2-3. Table 3.2-3. Frequency Adjustment Factors Storm Return Period Frequency Adjustment (years) Factor (C�) 2, 5, 10 1.00 25 1.10 50 1.20 100 1.25 Table 3.2-2. Surface Type - Runoff Coefficients Surface Type Runoff Coefficients Hardscape or Hard Surface Asphalt, Concrete 0.95 Rooftop 0.95 Recycled Asphalt 0.80 Gravel 0.50 Pavers 0.50 Landscape or Pervious Surface Lawns, Sandy Soil, Flat Slope < 2% 0.10 Lawns, Sandy Soil, Avg Slope 2-7% 0.15 Lawns, Sandy Soil, Steep Slope >7% 0.20 Lawns, Clayey Soil, Flat Slope < 2%a 0.20 Lawns, Clayey Soil, Avg Slope 2-7% 0.25 Lawns, Clayey Soil, Steep Slope >7% 0.35 Bowman - drainage.xlsx Drainage Basin Runoff Calculations 5425 South County Road 7, Fort Collins, CO Area Minor Major Initial/Overland Timel Travel TimeZ Final T� Intensity (in/hr 4 Basin Flow (cfs)5 Basin Length Slope Minor to Major to Length Slope Channel Velocity tt Minor Tc Major Tc (acres) Composite C Composite C 2-yr 10-yr 100-yr 2-yr 10-yr 100-yr (ft) (%) (min) (min) (ft) (%) Type (fps) (min) (min) (min) Historic A 5.000 0.22 0.28 630 1 41.3 38.7 NA 41.3 38.7 1.05 1.80 3.87 1.16 1.99 5.34 Developed A 5.000 0.27 0.34 630 1 39.0 35.8 NA 39.0 35.8 1.11 1.89 4.08 1.50 2.55 6.88 Notes: 1. Per Fort Collins Stormwater Criteria Manual Section 3.3.2. t.a�� t. � -cxc��vi. T� = v,s Where: C= Runoff Coefficient, dimensionless Cr = Frequency Adjustment Factor, dimensionless L= length of Overland Flow, feet S = Slope, percent 2. Per Fort Collins Stormwater Criteria Manual Section 3.3.3. V _ 1.49 R2/3S7/2 n Where: V = Velocity, feet/second n = Roughness Coefficient, dimensionless R= Hydraulic Radius, feet (Hydraulic Radius = area / wetted perimeter, feet) S = Longitudinal Slope, feet/feet And: L T� - vXeo 3. Per Fort Collins Stormwater Criteria Manual Section 3.3.4. A minimum T� of 5 minutes is required. T�-iso+10 4. Per IDF Table for Rational Method, Table 3.4-1 Fort Collins Stormwater Criteria Manual. 5. Per Fort Collins Stormwater Criteria Manual Equation 5-1. Q = CIA Where: Q= Peak Rate of Runoff, cfs C = Runoff Coefficient, dimensionless I = Rainfall Intensity, in/hr A= Area of the Basin or Sub-basin, acres Bowman - drainage.xlsx Concrete Washout Area (CWA) ■ 3� MIN. VEHICLE TRACKING CONTROL {SEE VTC DETAIL) OR OTHER STABLE SURFACE 12" TYP >4 1� --! I UNDISTURBED OR � COMPACTED SOIL \ 1 �� CWA-1 CWA INSTALLATION NOTES 8 X 8 MIN. SECTION A MM-1 CWA 2% 5LOFE � 3� 1 VEHICLE TRACKING CONTROL (SEE VTC DETAIL ) ONCRETE WASHOUT AREA 1. SEE PLAN VIEW FOR: -CWA INSTALL.ATION LOCATION. 2. DQ NOT LOCATE AN UNLINED CWA WITHIN 400' OF ANY NATURAL DRAINAGE PATHWAY OR WATERBODY. DO NOT LOCATE WITHIN 1,OflO' OF ANY WELLS OR DRINKING WATER SOURCES. IF SITE CONSTRAINTS MAKE THIS INFEASIBLE, OR IF HIGHLY PERMEABLE SOILS EXIST ON SITE, THE CWA MUST BE INSTA�LED WITH AN IMPERMEABLE LINER (16 MIL MIN. THICKNESS) OR SURFACE STORAGE ALTERNATIVES USING PREFABRICATED CONCRETE WASHOUT �EVICES aR A LINED A80VE GROUNO STORAGE ARE SHOULD 8E USEO. 3. THE CWA SHAL� BE INSTA��ED PRIOR TO CONCRETE PLACEMENT ON SITE. 4. CWA SHALL INCLUOE A FLAT SUBSURFACE PIT THAT IS AT LEAST S' BY S' SLOPES LEADING OUT OF THE SUBSURFACE PIT SHALL BE 3:1 aR FLATTER. THE PIT SHAL� BE AT LEAST 3' DEEP. 5. BERM SURROUNDING SIDES ANO BACK OF THE CWA SHALL HAVE MINIMUM HEIGHT OF 1'. 6. VEHICLE TRACKING PAD SHALL 8E SLaPED 2� TOWARDS THE CWA. 7. SIGNS SHALL BE PLACED AT THE CONSTRUCTION ENTRANCE, AT THE CWA, AND ELSEWHERE AS NECESSARY TO CLEARLY INDICATE THE LOCATION OF THE CWA TO OPERATORS OF CONCRETE TRUCKS AND PUMP RIGS. 8. USE EXCAVATED MATERIAL FOR PERIMETER BERM CONSTRUCTION. November 2010 Urban Drainage and Flood Control District CWA-3 Urban Storm Drainage Criteria Manual Volume 3 CONCRETE WASHOUT AREA PLAN � COMPACTED BERM AROUND � THE PERIMETER MM-1 Concrete Washout Area (CWA) CWA MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHaULD BE PROACTIVE, NOT REACTIVE. WSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE ERQSION, AN� PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPS IN EFFECTIVE OPERATING CONDITION. INSPECTIONS ANO CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. THE CWA SHALL 8E REPAIRED, CLEANED, OR ENLARGED AS NECESSARY TO MAINTAIN CAPACITY FOR CONCRETE WASTE. CONCRETE MATERIALS, ACCUMULATED IN PIT, SHALL BE REM�VEO ONCE THE MATERIALS HAVE REACHED A DEPTH OF 2'. 5. CONCRETE WASHOUT WA7ER, WASTED PIECES OF CONCRETE AND ALL OTHER DEBRIS IN THE SUBSURFACE PIT SHALL BE TRANSPORTED FROM THE JOB SITE IN A WATER-TIGHT CONTAINER AND DISPOSED OF PRaPERLY. 6. THE CWA SHALL REMAIN IN PLACE UNTIL ALL CONCRETE FOR THE PROJECT IS PLACED. 7. WHEN THE CWA IS REMOVED, COVER THE DISTURBED AREA WITH TOP SOIL, SEE� AND MULCH OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. (DETAIL ADAPTED FROA1 ❑OUGLAS COl1NTY, COLORA00 AND THE CITY OF PARKER, COLaRADO, NOT AVP1lA8LE IN AUTOCA�). NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD OETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH OETAIL SHOULD 8E USED WHEN DIFFERENCES ARE NOTED. C WA-4 Urban Drainage and Flood Control District Noveinber 2010 Urban Storm Drainage Criteria Manual Volume 3 Silt Fence (SF) �_�_� SILT FENCE GEOTEXTILE coMPAcrE� BACKFI LL FkOW -�_ EXISTING � ` � ~ ` GROUND 6" MIN AT LEAST 10" � OF SILT FENCE "TAI�" SHAL� BE 4" MIN BURIED 18" MIN SILT FENCE JOIN FIRST 36"-48•' TYP. SC-1 S� POSTS SHALL OVERLAP AT JOINTS SO THAT NO GAPS EXIST IN SILT FENCE, ROTATE SEC�N� POSTS SHALL BE JOINED AS SHOWN, THEN ROTATED 180 DEG. THICKNESS aF GEOTEXTILE HAS IN �IRECTION SHOWN AND ORIVEN BEEN EXAGGERATEO, TYP INTO THE GROUND SECTION A SF-1 . SILT FENCE ,v2„X,Y2.. (RECOMMENDED) WOODEN FENCE POST WITH 10' MAX SPACING November 2010 Urban Drainage and Flood Control District SF-3 Urban Storm Drainage Criteria Manual Volume 3 SC-1 Silt Fence (SF) SILT FENCE INSrALLATION NaTES 1. SILT FENCE MUST BE PLACED AWAY FROM THE TOE OF THE SLOPE TO ALLOW FOR WATER PONDING SILT FENCE AT THE TOE OF A SLOPE SHOULD BE INSTALLED IN A FLAT LOCATION AT LEAST SEVERAL FEET (2-5 FT) FROM THE TOE OF THE SLOPE TO ALLOW ROOM FOR PONDING AND DEPOSITION. 2. A UNIFORM 6" X 4" ANCHOR TRENCH SHALL BE EXCAVATED USING TRENCHER OR SILT FENCE INSTALLATION DEVICE. NO ROAD GRADERS, BACKHOES. OR SIMILAR EQUIPMENT SHALL BE USED. 3. COMPACT ANCHOR TRENCH BY HAND WITH A"JUMPING JACK" OR BY WHEEL ROLLING. COMPACTIQN SHALL BE SUCH THAT SILT FENCE RE515TS BEING PULLED OUT OF ANCHOR TRENCH BY HAND. 4. SILT FENCE SHALL BE PULLEO TIGHT AS IT IS ANCHORED TO THE STAKES. THERE SHOULO BE NO NOT�CEABLE SAG BETWEEN STAKES AFTER IT HAS BEEN ANCHOREO TO THE STAKES. 5. SILT FENCE FABRIC SHALL BE ANCHaRED TO THE STAKES USING 1" HEAVY DUTY STAPLES OR NAILS WITH 1° HEAOS. STAPLES AND NAILS SHOULD BE PLACED 3" ALONG THE FABRIC DOWN THE STAKE. 6. AT THE END OF A RUN OF SILT FENCE ALONG A CONTOUR, THE SILT FENCE SHOULD BE TURNED PERPENDICULAR TO THE CaNTOUR TO CREATE A'�J-HOOK." THE '�J-HOOK'� EXTENOING PERPENDICU�AR TO THE CONTOUR SHOULO BE OF SUfFICIENT LENGTH TO KEEP RUN�FF FROM FLOWING AROUND THE END OF THE SILT FENCE {NPICALLY 10' - 20'). 7. SILT FENCE SHALL BE INSTALLED PRIOR TO ANY LAND DISTURBING ACTIVITIES. SILT FENCE MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONOITION. MAINTENANCE OF BMPs SHaU�D BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STQRM THAT CAUSES SURFACE ERQSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHaULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. SEDIMENT ACCUMULATED UPSTREAM OF THE SILT FENCE SHALL BE REMaVEO AS NEEDED TO MAINTAIN THE FUNCTIONALITY OF THE BMP, TYPICALLY WHEN DEPTH OF ACCUMULATED SEDIMENTS IS APPROXIMATELY 6'�. 5. REPAIR OR REPLACE SILT FENCE WHEN THERE ARE SIGNS OF WEAR, SUCH AS SAGGING, TEARING, OR COLLAPSE. 6. SILT FENCE IS TO REMAIN IN PLACE UNTIL THE UPSTREAM DISTURBED AREA IS STABILIZEO ANO APPROVED BY THE LOCAL JURISOICTION, OR IS REPLACEO 6Y AN EQUIVALENT PERIMETER SEDIMENT CONTROL BMP, 7. WHEN SILT FENCE IS REMOVED, ALL DISTURBED AREAS SHALL BE COVERED WITH TOPSOIL, SEEDED AND MULCHED OR OTHERWISE STABIUZED AS APPROVEO BY LOCAL JURISDICTION. (DETNL ADAPTED FROM TOWN OF PARKER, COLORADO AND CITY OF AURORA, NOT AV.N1148LE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD 8E USED WHEN OIFFERENCES ARE NOTED. SF-4 Urban Drainage and Flood Control District Noveinber 2010 Urban Storm Drainage Criteria Manual Volume 3 Stockpile Management (SP) MM-2 %� �� ♦ � ► �` f f� � / � / \ � \ ` � \ � �� 1 SP / � SILT FENCE (SEE SF DETAIL FOR / �' INSTALLATION REQUIREMENTS) / STOCKPILE PROTECTION PLAN MAXIMUM ��/ SILT FENCE (SEE SF DETAIL FOR INSTALLATION REQUIREMENTS) SECTION A SP-1 . STOCKPILE PROTECTION STOCKPILE PROTECTION INSTALLATION NOTES 1. SEE PLAN VIEW FOR: -LOCATION OF STOCKPILES. -TYPE OF STOCKPILE PROTECTION. 2. INSTALL PERIMETER CONTROLS IN ACCORDANCE WITH THEIR RESPECTIVE DESIGN DETAILS. SILT FENCE IS SHOWN IN THE STOCKPILE PRaTECTION �ETAILS; HOWEVER, OTHER TYPES OF PERIMETER CONTROLS WCLUDWG SEDIMENT CONTROL LOGS OR ROCK SOCKS MAY BE SUITABLE IN SOME CIRCUMSTANCES. CONSI�ERATI�NS FOR DETERMINING THE APPROPRIATE TYPE OF PERIMEfER CONTROL FOR A STOCKPILE INCLUDE WHETHER THE STOCKPILE IS LOCATED �N A PERVIOUS OR IMPERVIOUS SURFACE, THE RELATIVE HEIGHTS OF THE PERIMETER CONTROL AND STOCKPILE, THE ABILITY OF THE PERIMETER CONTROL TO CONTAIN THE STOCKPILE WITHOUT FAILING IN THE EVENT THAT MATERIAL FROM THE STOCKPILE SHIFTS OR SLUMPS AGAINST THE PERIMETER, AND OTHER FACTaRS. 3. STABILIZE THE STOCKPILE SURFACE WITH SURFACE ROUGHENING, TEMPORARY SEEDING ANC MULCHWG, ERUSI�N CONTKUL SLANKETS, OR SOIL BINOERS. SOILS STOCKPILED FOR AN EXTENDEd PERIOD (TYPICALLY FOR MORE THAN 60 �AYS) SHOULD BE SEE�ED ANO MULCHED WITH A TEMPORARY GRASS CaVER ONCE THE STOCKPILE IS PLACED (TYPICALLY WITHIN 14 DAYS). USE OF MULCH ONLY OR A SOIL BINDER IS ACCEPTABLE IF THE STOCKPILE WILL BE IN PIACE FOR A MORE LIMITED TIME PERI00 (TYPICALLY 30-60 DAYS). 4. FOR TEMPORARY STOCKPILES ON THE INTERIOR PORTION OF A CONSTRUCTION SITE, WHERE OTHER DOWNGRADIENT CONTROLS, INCLUOING PERIMETER CONTROL, ARE IN PLACE, STOCKPILE PERIMETER CONTROLS MAY NOT BE REQUIRED. November 2010 Urban Drainage and Flood Control District SP-� Urban Storm Drainage Criteria Manual Volume 3 MM-2 Stockpile Management (SM) STOCKPILE PROTECTION MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHaULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE ERQSION, AN� PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPS IN EFFECTIVE OPERATING CONDITION. INSPECTIONS ANO CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. STOCKPILE PROTECTION MAINTENANCE NOTES 4. IF PERIMETER PROTECTION MUST BE MOVED TO ACCESS SOIL STOCKPILE, REPLACE PERIMETER CaNTROLS BY THE ENQ OF THE WORKDAY. 5. STOCKPILE PERIMETER CONTROLS CAN BE REMOVED ONCE ALL THE MATERIAL FROM THE STOCKPILE HAS BEEN USED. (DE7NL5 ADAPiEO FROM PARKER, CO�ORADO, NOT AVAItABLE IN AUTOCAO) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOU�D BE USED WHEN DIFFERENCES ARE NOTED. SP-4 Urban Drainage and Flood Control District Noveinber 2010 Urban Storm Drainage Criteria Manual Volume 3 Vehicle Tracking Control (VTC) SM-4 =4. . . . � ,' <',`` �" " =�.r �.�-{� '-1,. ��1 �TC 20 FOOT (WIDTH CAN BE LESS IF CONST. VEHICLES ARE PHYSICALLY CONFINED aN BOTH SIDES) SIDEWALK OR QTHER PAVEO SURFACE � .� .�f rJ ^�'� "{,.i -� :�-i� . -i .'-V �.� � -t .� -� � - � ;. "-� .: : ._�'� !'4,.! �{:_r �. � PUBLIC � ROAOWAY 50 FOOT (MIN.) Y P ? Y'`Y Y Y--Y Y ' Y� � Y I -1 -( ,�-( L� -f . -f �I -t -1 -t i y i -1 �K -1 Y�,�'�� y�.Y� i..� r{`_Y{ Y-1 Y� .y ��-1 i 1.. ., �:�:!� , �� ~a � ,� .,��` Y 1 Y � i• ~ ~•i � ..��-1 .� ��i —S � —4 -{ .�-�� :..` -�.1�"i, 'i . ^l �''-I _ � _ _ �-h 1 Y ~ L �F .. �{ "} ^t ' ; 'i ^S � . J J -• - �'��;-+�'=Ca"��%_, , ,` -, 9" (MIN-) � ^! ,._Y^{ ry-S 1 ,, , i ^-(. .. 4� t� t' :�_"`:.`;�`�.:; . . UNLESS OTHERWISE SPECIFIED BY LOCAL JURISOICTION, USE \ coor sEcr. ��03, �sHra #3 COARSE AGGREGATE OR 6" MINUS ROCK NON—WOVEN GEOTEXTILE FABRIC BETWEEN SOIL ANO ROCK INSTALL R�CK FLUSH WITH OR BELOW TOP OF PAVEMENT UN�ESS OTHERWISE SPECIFIED BY LOCAL JURiSDICTION, USE CDOT SECT. #703, AASHTd #3 COARSE AGGREGATE � 9'� (MIN.) I NON—WOVEN GEOTEXTILE FABRIC VTC-1. AGGREGATE VEHICLE TRACKING CONTROL November 2010 Urban Drainage and Flood Control District VTC-3 Urban Storm Drainage Criteria Manual Volume 3 COMPACTED SUBGRADE � �ECTIQN A SM-4 Vehicle Tracking Control (VTC) STABILIZED CONSTRUCTION ENrRANCE/EXIT INSTALLATION NOTES 1. SEE PLAN VIEW FOR -LOCATION aF CONSTRUCTIaN ENTRANCE(S)/EXIT(S). -TYPE OF CONSTRUCTION ENTRANCE(S)/EXITS(S) (WITH/wITHOUT WHEEL WASH, CONSTRUCTION MAT OR TRM). 2. CONSTRUCTION MAT OR TRM STABILIZEO CONSTRUCTION ENTRANCES ARE ONLY TO 8E USED ON SHORT DURATION PROJECTS (TYPICALLY RANGING FROM A WEEK TO A MONTH) WHERE THERE WILL BE LIMITED VEHICULAR ACCESS. 3. A STABILIZED CONSTRUCTION ENTRANCE/EXIT SHALL 8E LOCATED AT ALL ACCESS POINTS WHERE VEHICLES ACCESS THE CONSTRUCTION SITE FROM PRVEO RIGHT-OF-WAYS. 4. STABILIZEO CONSTRUCTION ENTRANCE/EXIT SHALL BE INSTALLEO PRIOR TO ANY LAND DISTURBING ACTIVITIES. 5. A NON-W�VEN GEOTEXTILE FABRIC SHALL BE PLACED UNDER THE STABILIZED CONSTRUCTION EN7RANCE/EXIT PRIOR TO THE PLACEMENT OF ROCK. 6. UNLESS OTHERWISE SPECIFIEO BY LOCAL JURISDICTION, ROCK SHALL CONSIST OF DOT SECT. j�703, AASHTO #3 COARSE AGGREGATE OR 6" {MINUS) ROCK. STABILIZED CONSTRUCTION ENTRANCE/EXIT MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHaULD BE PROACTIVE, NOT REACTNE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS� FOLLOWING A STORM THAT CAUSES SURFACE ERdS10N, AN� PERFORM NECE5SARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. ROCK SHALL BE REAPPLIE� OR REGRAOED AS NECESSARY TO THE STABILIZED ENTRANCE/EXIT TO MAINTAIN A CONSI5TENT DEPTH. 5. SEDIMENT TRACKED ONTO PAVED ROA6S IS TO BE REMOVE� THROUGHOUT THE DAY AN� AT THE END OF THE DAY BY SHOVELING OR SWEEPING. SEDIMENT MAY NOT BE WASHED DOWN STORM SEWER DRAINS. NOTE; MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH OETAIL SHOULD 8E USED WHEN DIFFERENCES ARE NOTED. {DETNLS AOAPiED FRaM CITY OF BROQMfIELO, COLORA00, NOT AVAILABLE IN AUiOGAD) VTC-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Erosion and Sediment Control Escrow/Security Calculation for The City of Fort Collins Project: 5425 South County Road 7, Fort Collins, CO BMP Amount Estimated EROSION CONTROL BMPs Quantity Units Silt Fence (SF) 310 LF Concrete Washout Area (CWA) 1 EA Vehide Tracking Control (VTC) 1 EA Reseeding Amount Unit Price of Seeding per acre: $720.00 Disturbed Acres: 0.96 Unit Price $2.00 $500.00 $500.00 Total Price $620.00 $500.00 $500.00 Sub-Total: 1.5 x Sub-Total: Amount of security: Total Acres x Price/acre: Sub-Total: 1.5 x Sub-Total: Amount to Re-seed; Miniumum Escrow Amount Minimum escrow amount: Final Escrow Amount Erosion Control Escrow: $1,620.00 $2,430.00 $2,430.00 $691.20 $691.20 $1,036.80 $1,036.80 $1, 500. 00 $2,430.00 "T/ee aniourlt of tlae security must be based on one nnr! one-F:alf times t/ae estinxn/e of U�e cost to install the approved measures, or one nnd oree-h�nlf ti��nes tlxe cost to re-vegetnte Ute disturLed [nnd to d,ry /nnrl grnsses bnsed upmz i�nit cost determined by the City's Annual Reve; etalion �uzd Slnbilizntion Bid, w/tiehever is greater. In no z��stnnce, wiU t/te nmottnt of secitrit� be Less than one tFtousanr/ five hundred do[lars ($I, S00) far resi�lerttial deve/op»Tent or tltree tha�tsand dollars ($3,000J for conemercinl r[evelopment" 11 /22/2019 2:17 PM C:\Users\megst\OneDrivelDocuments\Keefe CiviP2019-24_Spanjer\Bowman\Drafnage\Erosion Control\Bowman_Escrow.xls