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Home My WebLink AboutDrainage Reports - 09/21/2015AP—E7Engirleering 908 Laporte Avenue • Fort Collins, Colorado 80521 August 28, 2015 Mr. Glen Schlueter, P.E. Stormwater Department City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80521 RE: Final Drainage and Erosion Control Letter Bucldngham Place, Second Filing Dear Glen, City of Fort Coll'as A proved Pians Approved by / D6- We have prepared this final drainage letter for Buckingham Place, Second Filing for your review and approval. The only comments received on the previous submittal were from Jesse Schlam regarding Appendix C. Those comments are addressed in that attachment. The existing property is an undeveloped 12,529 square -foot lot on the east side of Third Street approximately 200 If north of Lincoln Avenue. It'is located in the Dry Creek Master Drainage Basin. This project proposes to develop to single family residential lots on the property: The following is a summary of the impacts to the drainage systems on and off the site. In addition, supporting calculations and a drainage exhibit have been attached. Floodplain The project site is located within the Poudre River 500-year floodplain (Zone X Protected by Levee). "At -risk population and essential.service" critical facilities are not allowed within the 500-year floodplain. No floodplain permitting is required for this project since single family residential is not considered a critical facility. Runoff The existing site (Basin E drains to the east and has 0.02 cfs and 0.78 cfs of runoff leaving the site in the 2-year and 100-year storms; respectively. In the developed condition, approximately 0.15 acres (Basin A) drains to 3ro Street and 0.13 acres (Basin B) drains to the east. Runoff from Basin A is 0.17 CFS and 0.76 CFS for the 2-year and 100-yearstorms, respectively. Runoff from Basin B is 0.02 CFS and 0.46 CFS for the 2-year and 100-years storms, respectively. Detention StotW The entire site is estimated to be approximately 50% to 60% impervious when built out. The Dry Creek Master Drainage plan estimated this area at 90% impervious. Due to the reduction in the planned imperviousness, the size of the site, and the difficulty in providing detention we are not proposing any detention storage with this project. j Water Quality The small site, existing location of the Coy Ditch, and proximity to adjacent storm sewer make it very difficult to provide structural water quality facilities. The residential site will have an area of non -paved surfaces at the front and rear of the lot. These areas will intercept the stormwater runoff from the roof and hardscape areas and provide water quality via "disconnected impervious areas". Erosion Control Erosion and Sediment Control devices will be implemented on the site as needed. The erosion control consists of typical silt fencing within the lots and a gravel inlet protection for the existing inlet in 3b Street receiving runoff from the project A separate Erosion Control Report has been attached as Appendix C. summary Due to the size of this small site, the proposed development of the site will have minimal impact to the stormwater. The runoff from the, site is less than what was originally planned for in the Master Drainage Plan, therefore. no on site detention or downstream improvements are included with this project I appreciate your time and consideration in reviewing this submittal. Please contact me at (970) 219-2834 should you have any questions or concerns. Bert Regards, Bob Gowin . APEX Engineering Attachments• • Appendix A - Calculation of Peak Runoffs • Appendbe B - Erosion Control Report • Appendix C — Grading Drainage and Erosion Plan II CALCULATION OF A PEAK RUNOFF US 1113 RATIONAL METHOD ( Project Title: Buc kiaham Place. Second Film ;atclvnert ID Basin EY Existing 2-year Discharge I. Catchmert Hfr6ologie fAta Cattdme++t ID= EX Area =�J.��9 Acres Breen l mperkiousness= 2.OD% NRCS Soil T1pe = 8 A. S. C. or D l FSiMaI trafamatim IiinchAtr)=Ct-P1!(C2+Td)"C3 Design Sam Return Period, Tr= 2 years C1 = 28.50 C2= 10.00 C3= 0.786 P1= 0.82 or"S (input return period for design stem) I input Ce a A c! C7; moot to 'live of C21 llnput R£ 'aloe of C31 pnput on lnr precepilatnn-see S^eeY Csvdr Inb Il Analysis of Floty Time (Time of Concentration( fora CatcMnent %nafF Coefficient, C = 0.03 Overide FilneB Coefficient. C = (enter an arefide C value if desired, or leave blank toaccept calculated C) 5-yr. FUncff Coefficient, G5 = 0.08 Overide 5g r. Randf Coefficient, C = (enter an oeride G5 value IF desired, a leave blank to accept oalculaed C-5. ) IlrRtration S"&^L rc :'Y - 11e. Dla..tl.r C. k. 1 It.r\ I e.r.s. A' Vi C$.ar -ea;. �Ilage. $LO-S 'aEeld >'.--AE_: S �3re- $'Noe► i' 21r. ✓ -->8 zea �� Calculations Ze3:• son Lr4r 5-.r YtCS 'CA PCA C s L RJ'Iprf Cw" cones, axe Vew. V :I've TT tt: t C-5 tts m1%;w. RUA rout "Out na;l ww woe: Overland OAMOD 120 0: 0.10 20.14 3 4 Sun ' 0 Co^nputed Tc = 2'0.14 ?!;oral Tc= 10.97 V. Peak Runoff Predction usitg C7Md c ctionusig Regional e Rainfall Intensiy at T, I = ' 91 mc" hr RFamtall ktensrtyatTc 1 = 2.16 mch hr =aac = '3¢. C. -- es Peak Flouraw Cpcs 3rd Street - UD Rational Basin Existing 2yr Existingxls, Tc and PeakQ 7f152015, 1245 PM 11 CALCULATION OF APEAK RUNOFF USING RATIONAL PAETHOD Pryeot T a le. Sucltndham Place, Se.ord Filing Catchmere IDS Bas n EX. Ex, song 100-year 0, cha rqe L Catchment MydmloW Data CaChmentlD- EX At" = 029 Aces Percent enperrousness= 2.00 t. NP,CS Soil Type= SA. 6. C. otC 1. fla l lill an I lehetehe) - C1 • P1 f(C2 a Tdl-C3 Dil Sbrm Pli Period. Tr = 1-30 ASM Ct= 285O = lox C?= 2793 :.es ImputreLm penod tot Oil sbrm.l Imput the vake o f C1) I input the wahw Of C2} I mpw the value 01 C3) input onedhr pirecau bon --sae Sheet -Despn Info ) 11. Analysis of Flow Time [Time of Concentration) fora Catchment Run "Se" *m C 0 3! Dserde Runoff Ccercoert C = ,File' a' o-.*,,:e C ielue ,f snow, or keaM blank D aumt pal0ulaed C.1 5•y %Mff Coefyk:ert. C ! = D'78 Ovw+de 5•y Ru -fCoerFcent C= 'e IW an o.erde G=_vlu*, l oe lied. o r IWM blank m aGoept:W m IV" C-5i Ilutaraehln / / eiaWe& LUM lerel Se. 01 dd�c F3i. D4wder .•..- IYavf Tmjp+ Tine tiamir uralw PBM Neil& < seelaae Pee pabw2 ten Solon SRlb1 WIe9 Seats Lam om"a Metals Seel Fpa� Gcve a^x 25 S 7 10 tS11 caim+laapni. Rea:' Spot Lei h S r MUM Felt Fbw S 1 fihmr :M Melt, Time car Ave If Tr n c-5 TA nimee C,erlarki n0A 0.010D roJ 120 wtpA 309 1.4A Qjwl 3,10 WID1a 20.14 a Sum 120 Co mputxl Tc = a'17. 11 Repoeal Tc- 10.07 N. Peak Ruist,111Pmckchu%frigCu wIo4 c Ion ulrvg e Rartall toaenmtyatTe. I= SS7 mcn hr Ranbe nenmyatTa l= 7.5! mm nr Pack Floe rate. Op =ck peak Flmrrae. OP = D.78 -1D 3rd Street- UD Ratonal 6aen Emtrg 1Xy Ex"Xi& Te WW NakC 7r15,2015. 12:aS PV to LCULAT ION OF A PEAK RUNOFF U SING RATIONAL METHOD PrWct Title. Bickteharn Place. Second Film Catchmerit Q Basn A. 2-ywr Discharge L 64tmert Rl"b9c Data Catahm tID=A Aries- 15 Aces Rrcentlmpersiausness= n'00 :. ARCS Soil Type = 6 A. S. C wD S RanfaS nfor nation I fi chM) = C1- P1 i(C2+ Tdll"C3 Design StamRetum Period, Tr . 2 years = 28.50 C2= 10.00 C>= 0.786 PI= 0.82 'r 7es (input return period fa design storm ,rout ft .alueofC11) ,rc.t" Oka ofC2) '•c.tthe wW[ofC3) -put onealr pieWtanon see Sreet Despr Irt; 11. Analysis of Ra•: Time (Time of Concentration fora Catehnert Runoff Coefficient, C = 0.51 Owride Runoff Coefficient, C = (enter an overide, C value if desired, a leave blank to accept calculated C) 5-yt Runoff Coefficient, G5 - 0.54 Oveide Syr. Runoff Coefficient, C = (enter an oleride G5 value if desired, a leave blank to accept calculated CZ.) lei,tatk== IV - eaa� � 1�dF1YIf {LR Dlrwrm 4r6rn� l CalalanonS =eat" sine .tl .. !-. r NtCS 'o:. `ca lC 5 l RaMr, CWT L>xuer- i X V*=0 V 'I'ne nn ! C-5 fai TFYJe6 haA mi anal "a.' ww Rlm.l aian . 1 .-'1 0.15 114 :).30 1. 1 24 2 a a - co. uted Tc= 1 F$groral Tc - 11.05 Peak Runoff Piedchonusrg Canpttedl diction using Regional Te Fainfall Intensity at Tc, 1 = 2.1T } a -a, Ir.engtyatTa l = 2.13 it chuff F¢ak Fi wral. Op • �14 �E =eak Rlevnr. Op =-la cis 3rd Street - UD Rakmal Basin A29r STOFIM A ids. Tc and PedkQ 7 A W01 S. 1251 FM CALCULATION OF A PEAK RUNOFF U SING RATIONAL METHOD Prwct Tole dlekir inam Place. Second Fdm atclmerlt ID Basin A. 10C-Year Runoff L Catchment Hydrologic Dau Cmmnrert ID = A Area=--T- ITAxes Weentlrryerviousness= 75 j,D'. NRCS Soil T1pe = 9 A., 9, C Vr C 1. Fambil Infamatim I(rchh1=C1I PI i(C2+Tq^C3 Oesign Slam Return Period, Tr = 100 ,eats 10.0 C2= 10.00 C3= 0.786 PI= . snores (input retum period for design =m) (mpvtbe WueofCI) (input ffa %Okae of CZ) (input the blue of m wvAone4kpedpt06pn ---SheetCeKrlrt': It Analysis d flow Titne(Tioe of Concentratiortf fora Catchmert Fkinon Coefficient. C = 0.66 Ovende R4naff Co?fficlent, C = (enter an ovende C value if desired, a leave blank to accept calculaed C) 5-9r. Punch Coefficient, G5= 0.54 Oueride 5yr. Farnch Coefficient, C = (enter an overide G5 value if dewed- a leave blank to accept calculated C-5.1 la �tob.. LEGS Wx� 1 yr t�fee . Fla. UIaRM1I C.YLrw1 W xa r newer^�,. 'Fly _3-, t ', r_ eeax:. =x past_E 9are s-ae.. CalWlations 5 L R. - use^ a.Ze Vebcer 'ene T 1 - - 711f TM.Iee eland -35155 m =4 X5J '.4 4- 4 S..r :amp-tec T-= lox Ft-gio a. T 71.49 V Peak Runoff Padetion usmg =puled Tc diction using Regional Te Painfall Intensity at % I = m cr r Ra'afe Irnsi"tT a = TM intithr Peak Flawrae, op = '� -,E Peak Flowral. 3p ck 3rd Street - UO Pauonal Basin A100yr STOF MAids, Tc and Pe*Q 7A 52015, 1252 PM CALCULATION OF A PEAK RUNOFF USHIG RATIO IIAL METHOD Frotect Tribe Bucknpnam Place. Second Fdm ;atctnery ID Basin B. 2-year Discharge I CatcM^.ere Hydrologic Data ;a:T .EntIC = ? A -ea = ' 3 Aaes Rwr ni lrrperaaime55= )�'. e Ranfan Information I (kwh r)= C1 • P1 r1C2 a Tq•C3 Design StortnRettm Period- Tt = 2 years C' = 28.50 C2= 10.00 C3= 0.786 PI= M ,n"s (input return period for design stain) Input tl+e *ue of C1 S (input tine Ialue of 027 i input the *ue of C3) :input one-ty preapitetron-iee Sneer Design Int'S ICI. analysis at Ray Time (Tim d Catcentra" fora Catchrxre Rinch Co6how. C = 0.06 Overide F';Uncff Cceffident- C = (enter an wetide C value if desired, a leave blank to accept calculated C) 5-gr. Amoff Cceffident, C-5. 0.14 Oveide 5 9 r %noff Coefficient, C = (enter an aeride C-5 value if desired, a lease blank to accept oaloulated C.S.I leytratim Ire .a I Wrk:lF` 'Fw _3I . taalted }I»la FLwlO Sw SWilS -sr:'6 ut0.'C afetu a.6 )a" Flow :o-NK anx- 5zo Calculations 44a.- S.,r NtCS Fox Fbx aV" Coat Mnuer- ance vexes v lrne r •D1. Cal -A ^ i,. rp_' 0.etkA nrt O.W o.,w Overland ).)EJ) 50 14 ) 12 7.19 4 r i Con cried Te =1,15 Regional Tc = 1028 Iv Peak Runoff Pre3ctionusi g Canpteed Tc etion using Regional TIM Rainfall Intensity at Tc, I = 2.5) :rer Rainfall tr*^Styat% 1 = 2'9 '-or r. c" F _. - ).GZ :'s Peak Pow rare, Cep = ^2 rs 3rd Street - UO Rational Basin 1321jr ST RVIExls. To and PeakO 7A W015. 1253 FM 11 CALCULATION OF A PEAK RUNOFF USING RAT C NAL METHOC Project Ttle 9uckmham Place. Second Film Catct"Prt IC Basn B, 100-year Ciscturye I Catchment Hydrologe Data Catdtnertt IO= 9 Area- 12 A7�. Percent l rtperueusress= " 7. 1. N RCS Soil Tyne= 9A 5 C.. C. l Rainfall Information I Ii ctNr) = C1 • P1 ifU - TC)"C3 Design StamRelurn Period, Tr : 100 years C' = 28.50 C.2= 10,00 q= 0.793 PI. 2.91 r7es (input return period for design =m) rc.t to jii :e s' C: �rpot Pe 8::.e c' C2 vput one-rr preW taLo-: se e Sheet-Dewitt(b) It Analysis of Rw Time rTinre d Corcentratiorrl fora Catctmer Funolf Coefficiem. C = 0.41 Oseride RmncN Coefficient, C = I enter an oaeride C value if desired, a leave blank ttaccept calculated C) 5-yr. Fund Coefficient, G5 = 0.14 Overide 5yr, Runoff Coefficient, C = (enter an ovende G5 value if desired, a leave blanktoaccept calculated C 5.) 9hw fdGfffi �1 p.e aerk: eviawmi; Fbw Dlsdn c.ra�.r ,c-c ..- rta. 'iU3t •.]a 1I �ry , S 'NO Aeli ' t •.'ea;s:. =ke Pas.e lMe�I 5AMMwsei I > abw Dana 9a7ec II1II( SW cam. --alculations 5ea:. sicoe Lengr S..r PCs ?me 'C" s L RJW. ow. 0 IeI- ana Vem V TI'm 'T C-S X 'iL'IGR 7.t oJtaa epJr c_�, atAa land 7 l`)- 5i 0 1 .1 t 3 4 un ti C,omj aTc= - Reg*mj Tc= ::b V Peak Ruoff Pietliction usrg Campraed Tc PcIlictionusag Regiorail Te Rainfall Intensiy at % I = e 70 k:chhr Ramtall Intn9tyat% 1 = 7153 mm m Peak Femme. Qp = I7J ch Peak Plriarae. Qp CS 3rd Street . UD RAmal Basin 6100yr STOPMENIs, Tc and PeakO 7A 5f2015, 1254 PM Appendix A Calculation of Peak Runoff Appendix B. Erosion Control Report Fort Collins, Colorado A. Site Description 1. Construction Activity Description Construction activityincludes installation of BMP's, grading,, utility (sanitary sewer and waterline) construction, removal and replacement:of asphalt and concrete in 3ro Street, and on -site home building construction activities. 2. Proposed Sequence for Major Activities The project is expected to be constructed. in two phases. Phase one consists of the installation of an 8" wastewater main in 3^d Street Phase one also includes the installation of two wastewater service and water service connections to the two Proposed lots. These will be stubbed into the Proposed lots three feet past the front. property line. The sequence of construction is expected to consist of the following: • Installation of inlet protect for existing inlet on 3r^ street located along the west side of the street to the south of the project site.- • Pavement cuts and removal of asphalt paving within 3ro Street for' installation of utilities. • Installation of utilities. e Asphalt patching in 3^d Street • Construction is anticipated to begin in September, 2015, and is expected to take two weeks. Phase two is expected to consist of construction of single-family homes within the two Proposed lots. These homes are expected to be constructed by others after phase one is completed. The anticipated sequence for major construction activities is follows: e Installation of erosion control as per City of Fort Collins standard detail D- 52. • Installation of on -site water and wastewater services. e Earthwork, including cuttfill on site. e Construction of building foundations. • Construction of buildings. • Final site grading and landscaping.. e Construction is anticipated to begin after Phase:One.completion. It should be noted that the curb/gutter, paving improvements, detachedsidewalk and driveway aprons will.be constructed as part of City capital project Erosion control for that.construction willbeprovided by the city project 3. Area Estimates Phase One construction is expected to disturb approximately 2600 square feet. This area is located within the existing right-of-way for 3rd Street Phase Two construction is expected to disturb 12,529 square feet This are is located Within the two proposed residential lots 4. Soil Description Earth Engineering Consultants completed the soils investigations for the project site and presented the results in the Soil Description and Limitation Report; 3^+ Street Pavement Section Design, Buckingham Place, Second ffing, Fort Collins, Colorado. According to this report, the surficial soils are mainly clay loam identified specifically as Loveland clay loam and Table Mountain loam. These soils exhibit low strength and shrink/swel_i potential and are unstable surficial soils. 5, Existing,Vegetation The existing site is undeveloped with approximately 60% vegetative cover. The vegetative cover consists of native grasses and shrubs. There is a large. amount of bare dirt on the property that appears to be driven on regularly. 6 Location and Description of Other Potential Pollution Sources Potential pollutant sources indude:sediment, uncovered soil, construction machinery, building materials, and fertilizers. It is anticipated that any storage of materials or machinery will be on site and surrounded by silt fence or straw wattles. 7. Non-Storinwater Components of Discharge According to the Preliminary Geotechnical Evaluation, 3ro Street and Buckingham, Fort Collins, Colorado by Earth Engineering Consultants:. Free water was observed at depths on the order of I I to 14 feet below present site grades atthe time of drilling. Those depths are on the order of 4 fee, orless below the apparent surface;of the native soils At these depths; is is expected that groundwater may be encountered during the construction of utilities within Phase One. If groundwater is encountered, the contactor shall obtain state and local dewatering permits as needed. The other non -storm water components of discharge include water line Oushing, irrigation to establish seeding, and watering for dust mitigation and compaction. A concrete truck washout will be provided within the:site. B. Receiving Waters This site is located in the Dry Creek Drainage Basin of Fort Collins, Colorado. Runoff from the construction within 3rd Street drains towards an existing inlet on the west side of 3rd Street, south of the project site. The proposed lots will drain to3b street -and/or adjacent property to, the south. B. Stormwater Management Controls I. SWMP Administrator The SWMP Administratoris currently:. Mr. Charles Meserlian 700 N. College Avenue Fort. Collins, CO 80524 Phone: 970-490- 1251 Fait: 970-484-6695 2. Identification of Potential Pollutant Sources This section focuses on the identification of the potential pollutant.sources-and briefly discusses the Best Management Practices (BMPs) that will be used. More information on the BMP's utilized on this site is included in the next section " 3. Best Management Practices". A. All disturbed and stored soils; It is expected that there will be stockpiles of dirt on the site from the utility installations and the foundation excavation. Silt fencing_, as per Fort Collins standard detail D-52, is proposed to control sediment B. Vehicle tracking of sediments The construction is so limited on this site that vehicle tracking control pad has not been shown on the erosion control plan.. At the end of each workday, the Contractor shall sweep or scrape 3rd Street to dispose of debris that may have accumulated during the workday. C. Management of contaminated soils There are no known contaminated soils on the site. However, if the contractor encounters contaminated soils during the construction process they should stop construction immediately and; notify the appropriate government authorities in accordance with good constriction safety and practice. D. Loading and Unloading operations Loading and unloading will take place on the site. Silt fencing shall be installed to control sediment.from site onto the street. E.. Outdoor storage activities (building materials, fertilizers, chemicals, etc.) Storage of construction materials (prior to installation) may include water and sanitary sewer piping, home building materials, soil and/or fertilizers. All materials stored longer than one week will be placed on pallets and�covered to prevent direct contact with the ground and potential surface runoff. F. Vehicle and equipment maintenance Vehicle and equipment maintenance are not expected to be needed, and will,not be allowed on site or on 3rd.Street. Should emergency maintenance be required, it shall be performed on the hard surface or gravel areas at least 50' from any stormwater feature (ie inlet, storm,sewer, concentrated runoff,.swale, etc.) G. Significant dust or particulate generating processes The Contactor shall comply with applicable air pollution control requirements of the City. The Contractor shall take appropriate actions to minimize atmospheric pollution and take reasonable precautions which shall include, but not be limited to: 1. The use of water for control of dusts for construction processes such as demolition, grading, or the, clearing of land. I Covering, at all times when in motion, open -bodied trucks transporting materials likely to give rise to airborne dusts. H. Routine maintenance activities involving fertilizers, pesticides, detergents, fuels, solvents, oils, etc, Chemicals, fuels, lubricants, and paints typical with building construction stored on - site will be in water tight containers and covered as necessary and stored in a bermed area, a storage building, or within a vehicle to act as secondary containment I. On -site waste management practices (waste piles, liquid wastes, dumpsters, etc.); Waste piles should be covered or surrounded by silt fence or straw wattles. Liquid wastes should be collected and stored in covered containers and disposed of properly. Solid waste materials, including disposable materials incidental to the major construction activities, Will be collected in on -site dumpsters. The containers Will be emptied periodically and trucked away from the site. Dumpsters shall have covers. J. Concrete truck f equipment washing, including the concrete truck chute and associated fixtures and equipment; A dedicated concrete washout area is notanticipated to be necessary for this project The contactor shall clean out equipment away so that runoff is not allowed to leave site and enter 3ro Street, the Coy Ditch, or neighboring properties. K. Dedicated asphalt and concrete batch plants, There will not be dedicated asphalt or concrete batch plants on this site.. L. Nonmindustrial waste sources such as worker trash and portable toilets Worker's trash shall be disposed of in an onsite dumpster. The site should be.free of wash at the end of each working day. A portable toilet shall be utilized by construction personnel and serviced regularly by a commercial operator. They shall be located a minimum of 5 feet from the curb or 50 feet from inlets and must be anchored.. Sanitary facilities shall not be located on hard surfaces that may promote tipping. M. Other areas or procedures where potential spills can occur. BMP'ssuch as tarps and drip pans should be used for painting, stucco, dry -wall etc. operations C. Best Management. Practices (BMP's) Once construction activity begins, Best Management Practices (BMA's) intended to contain sediment onsite must be constructed, inspected and repaired as necessary:, Such controls must be functional before upslope. land disturbance takes place. The BMP s will be installed as shown on the Grading and Erosion Control plan shown in Appendix D. They must be supplemented as on -site experience proves necessary in order to control sediment, pollutant discharge, and insure public safety. The following temporary and permanent BMP's will be installed and maintained to control on -site erosion and prevent sediment from traveling off -site during construction. The descriptions below provide some information about each BMP, but further information can be found in Urban Storm Drainage Criteria Manual, Volume 3 - Best Management. Practices by Urban Drairiage,and Flood Control District. • Construction Fence is a temporary BMP. The contractor is to place construction fencing around development as needed to limit access by construction equipment and personal vehicles to designated areas of ingress and egress. Since the majority of site will soon be surrounded by a permanent fence, there will be limited construction fence needed on this prbjecc • Inlet Protection is a temporary BMP that helps prevent soil and debris from the site from entering the storm drain inlets and usually consists of a sediment filter around or upstream of the storm drain inlet. Inlet protection allows storm water to flow into the drain but only after excess sediment has been filtered out. Inlet protection will be used on existing and proposed storm inlets and will be installed at such time as construction of the storm sewersystem occurs.. Inlet protection for this site will consist ofwattles, which are meshed netting "tubes" filled with straw, excelsior, :or coconut fiber placed around grated inlets and curb inlets. Wattles require proper installation and maintenance to ensure their performance. Sizing shall be per manufacturer's recommendation. • Regular Meetings is a temporary and non-structural BMP. Regular meetings with on -site workers including builders, suppliers, landscape personnel, etc should be conducted so that they are kept up to date with site standard operating procedures. • Silt Fence is a woven synthetic permeable fabric that filters runoff. Silt fence is a temporary barrier that is installed prior to earthmoving activities.and is placed downstream of areas where runoff from construction activities is expected to occur, especially along the site perimeter to allow sediment to settle from runoff before water leaves the construction site. Silt fences will be installed per manufacturer's recommendations. Silt fence encourages sheet flow and is not intended to be used in areas of concentrated flow. if concentrated flow is encountered during the placement of the fence, an alternative BMP shall be used and the SWMP should be updated to reflect this change. • Street Sweeping and Vacuuming removes sediment that has been tracked onto roadways to reduce:sediment transport.into storm drain systems or a surface waterway. This practice should be used on the adjacent paved road to the construction site. Paved roads should be inspected on a daily basis and more frequently as needed. • Temporary Seeding is the establishment of a temporary vegetative cover on a graded area that will be.exposed for longer 30 days. Temporary seeding can be used on areas requiring temporary protection that will eventually need permanent vegetation at the completion of the construction or it can be used for areas that will be re -disturbed after a period of inactivity. Wind Borne Sediment and Dust Control measures will be provided during the construction process to control wind borne sediment. During grading activities, water will be applied to the disturbed soils°forthe purpose of maintaining cohesion With clay type soils and also to meet moisture requirements for compaction of disturbed soils. Other measures of mitigation for wind erosion may include the timely installationof seed and mulch following the establishment of final grade, and the timely installation of pavement following completion of utility trenching operations and curb construction. Open areas should be kept in a roughened condition. • PermanentSeeding and Planting is the establishment of a permanent perennial vegetation such as trees,.shrubs, vines, grasses/sod, or legumes on exposed areas for final permanent stabilization in order to provide stabilization of the.soil by holding soil particles in place. It also reduces storm water runoff velocity, maintains sheet flow, protects the soil surface from erosion, promotes infiltration of runoff, ;and improves wildlife habitat. • Preservation of Existing Vegetation should occur where no construction activity is expected to occur. Preservation of natural vegetation is generally a permanent BMP and is applicable to construction sites with pre-existing vegetation. Only land needed for building activities and vehicle traffic needs to be cleared. D. Erosion Control Sequencing Sift Fence and Inlet Protection - Before construction begins, silt,fence.and gravel inlet protection will be. installed.. These erosion control devices shall be. in place, functional, and maintained during and following the construction operations. Durine Construction Street Sweeping and Cleaning —The: adjacent streetshall be swept and cleaned on an as - needed basis to ensure sediment is not being tracked away from the, construction site. Wind Borne Sediment and Dust. Control — Wind borne sediment and dust control measures should be implemented during grading activities. Permanent Seeding— Permanent seeding or landscaping shall be placed immediately in areas that are final graded and where little future disturbance is expected. In particular, permanent seeding should be included on the side slopes of the detention pond.. Temporary Seeding— The majority of the landscaped areas will be permanently seeded/planted. However, if any of the areas are left disturbed without permanent stabilization 30 days after grading, temporary seeding will be required. Post. Construction BMP's shall be maintained until final site stabilization: E. Final Stabilization and Long-term Stormwater Quality Final stabilization is reached when all soil disturbing activities at the site have been completed and vegetative cover has been established with a density of at least 70 percent of pre -disturbance levels or when equivalent permanent erosion reduction methods have been utilized, Upon final stabilization, temporary BMP's may be removed. Water quality will be provided through established landscaping and pervious areas on the site. F. Inspection and Maintenance Procedures Appropriate measures shall be taken to inspect and maintain existing erosion control features, as described herein or per manufacturers specifications (whichever is more stringent) and install new erosion control elements as needed. The temporary BMP s will be inspected and documented at minimum of once every 14 days and after each precipitation orsnowmelt event Records should include complete inspection reports for each inspection, maintenance and/or repair. A record -keeping system is recommended in managing inspection and maintenance reports and should include all maintenance records, spill response, weather conditions, training, correspondence, etc. Preventative maintenance also involves the regular inspection and testing of equipment, timely maintenance of the equipment, and complete records of the maintenance:and inspections of the equipment The maintenance and inspection records should be kept on site and made available upon request Inspections must include the observation of the construction site perimeter, runoff discharge points; disturbed areas, staging areas (including concrete washout areas and fuelingareas), erosion and sediment control measures identified, and any other structural BMP's that may require maintenance. The inspection must determine if there is evidence of or potential for pollutants to enter the drainage system and if they should be modified, replaced, or added to. The following list includes some recommended.maintenance procedures: • Erosion and sediment control measures determined, upon inspection, to be:in need of repair shall be maintained before the next anticipated storm event or as necessary to maintain continued effectiveness of erosion and sediment control measures. If it is impractical to maintain erosion and sediment control measures before the. next storm event, maintenance should be accomplished as soon as practical. a Locations where vehicles enter or exit the site shall be inspected for evidence of sediment being tracked off -site by construction traffic. Such sediment shall be removed before it can be conveyed to the receiving storm drains or creeks. • Seeded areas will be checked to see that grass coverage is maintained. Areas will be watered, fertilized and reseeded as needed. It is the responsibility of the Operator to maintain effective pollutant discharge controls. Actual physical site conditions or contractor practices could make it necessary to install more control than are shown on the Erosion Control Plan. For example, localized concentrations of surface runoff or unusually steep areas could require additional erosion control devices. Assessing the need for, and implementing additional controls will be a continuing aspect of the SWMP until final stabilization.. This plan intends to control water -borne and liquid pollutant discharges by some combination of interception, filtration, and containment. Parties implementing this plan must remain alert to the need to periodically refine and update the plan in order to accomplish the intended goals. Sediment that has escaped the construction site must be removed at a frequency sufficient to minimize off -site impacts. G. Erosion Control Surety Calculations Project: Ewa mgnv _c;dre EROSION CONTROL BMPS Silt Fence (SF) Inlet Protection (IP) Vehicle Traclong Control (VTC) (add all other BMPs for the site In this list) BMP Amount Estimated Units Ouantity L.F 1050 Ea 1 Ea 1 Reseeding Amount Unit Price of SeeOmg per ao $1, 050.00 DisturbeC Aves: 9_'9 Unit Price $2.50 $100.00 $185.00 Sub-T otat 1 5 x Suc-Tolat Amount of security: Total Acres x Pricelacre: Sub -Tatar 1, 5 x Sub -Tot at Amount to Re -seed: Minumum Escrow Amount Ntin imu m escro w amo un t: Final Escrow A rrourt Eroson Control Escrow: Fields in yellow should be amended for this project Total Price $2.625.00 $100.00 $185.00 $2.910.00 $4.365.00 54,36500 i4r1-1011 5304.50 5456.75 S45G 75 53,000.00 54.365.00 -?kr anorar orUr wtarm' a rvrbr ba>d on onr and oaMadrawrr Mr ran m ofW Loam oral Mr a�ra•rd n rasmra m oar mmd ow-ia�r awrr rk, rmr m rr-vrpraW Ae' drnrDrd bad ID dn' kad pmsat 9mrd upon watt cmtdm>.ud Lt' Ar C:a''s.{nay d Itnvpn�cn and SrahB;aoon 13W, rrk Ykrur S DKQZr. Ill a0 m Hmt rl. a+.lirhr W aWtt �#:tU:'J' N:/rf AM Dal dtaaroad f trY AWdrfd dN10rt rS +Q7.r far Krd'n.^.a( d(r'(daWta: Pf AKt A= nd doU?rri5�.9Wr for :an err;st dnr/orert'' Appendix. C Grading Drainage and Erosion Control Plan ■� NORTHERN ENGINEERING Manhattan Town -homes Erosion Control Cost Estimate Project Number: 1124-001 Location: Fort Collins, CO Date: August 26, 2015 Total Acres: 2.80 Estimated Unit Total EROSION CONTROL MEASURE Units Quantity Price Price Silt fence L.F. 2660 $1.85 $4,921.00 Straw Wattles (9" z 1 O' dimension) each 27 $20.00 $540.00 Area Inlet Protection (e.g., landscape drains) each 0 $20.00 $0.00 Curb. Inlet. Protection (w/o grate) each 2 $75.00 $150.00 Area Inlet Filter (i.e., Mirafi Dandy Sack) each 0 $75.00 $0.00 Rock Sock each 5 $25.00 $125.00 Vehicle Tracking Contol Pad each 2 $700.00 $1,400.00 Sawcutting Pollution Prevention L.F. 800 $1.00 $800.00 Street Sweeping and Cleaning per hour 12 $70.00 $840.00 Vegetate Landscaped Areas acre 2.80 $1,325.00 $3,710.00 Sub -Total; $14486.00 1.5x Sub -Total: $18,729.00 Option T I BMP Costs Amount of security: $78, 729.00 Option 2 1 Cost to Re -seed Disturbed acreage: Total Acres x $1325/acre: $3,710.00 Sub -Total: $3,710.00 1.5 x Sub -Total: $5,565.00 Cost to Re -seed: $4,200.00 Option 3 1 Miniumum Escrow Amount Minimum escrow amount: $3, 000.00 Fief iffscrow Amduiit' Erosion Control Escrow: $18, 729.00 NOTE: 'Total Acres' represents total A jjt y area; _ '?e )); I lz) 12 .-',RD ST.('- EE I )RD SIR EET -•RD STR_-i INC LPJ �- AV_ ) 1 (RAVEL BBET PROTECTOR TO BE I J li BEHOVE AND REPLAM ETSNNG CONCRETE C/G WSiALL ON ENSORG INLET AND S AK AS NEEDED, (SEE MAL D-25)— I a —I— N J —I — IP APFWOkNATE UNITS Of51REET CUT PROP B' SEVER TINE — (SEE NOTE 2) SEE UDUTY PLAN 2. 3. 4. TtPE i WVDIAY-APPROAOR BEIMEEN CURB AND WALK — — _ -- — — — — — — 6. TO BE CONSTLIUCM BY, OTHERS MOTH - MO. 7- FL-FL ----- - — — -- 3RD STREETGO - - OF WAY FUTURE WRB, GUTTER AND SOEWAK BY OTMRS _ _ - _ _ — — — — • _ ---_—_ — UM ESNs aao' �' �• � i leJ 1_ _ Y ( W CON AY Ro GWCVEWJ / _ DRIAY SILT FORCE (rn) 4949 (SEEDETALs D-28 AND O-W) EnVELIRE — , i /c LOT 2 (a)n e' LOT 1 ��-�---- %iii� LINCOLIV A- ' E 04 LINC.OLN AVE aT mRCE (rYP) (YE TETRAS o-2e Araa:O-sz) �BM1 FFE _ 49.85 ADJACENT GRADE = 49:35 MANAGE BASIN' BONDMT (TYP) I EROSION AND SEMAENT CONTROL TO,BE INSTAL FOR EACH LOT (SEE DETAILS o-u AND o-52) { sD 1 c ar FFE ® 9.85 ! '\ ADJACENT GRADE = 49.35 1 FR090H AND SEDWENT CONTROL TO. BE RSTALL FOR EACH LOT (SEE DETALSV-23 'AO 0-52) 1 4947. UTURY EASORIT iyar rr I HO� �V- UTRITT EASFAENT S G- - - - _ _ - - - - - _ _ - _ _ - - _ - C,DELL PREWIWa COdPAN'( I ! SF :EPLAT �4 E� �i lir _)8 SRD STREET TOGS STALL BE OIPECTED NA. 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