Loading...
HomeMy WebLinkAbout1.0 Application.pdf),,. ' , ,... GARFIELD COUNTY Building & Planning Department 108 81h Street, Suite 401 Glenwood Springs, Colorado 81601 Telephone: 970.945.8212 Facsimile 970.384.3470 www.garfield-county.com Floodplain Development Permit GENERAL INFORMATION General Location of the Property: 8 m_rh~o of Hie t/.nr-!Wcd I 'Ii! of ·ns. R9ZW of tk 6tb PoMe Met;dti.zr. I &fi-eJcf Cowi~r,. C0 5<'disib /{), Existing Use & Size of Property in acres: 7'.3 ClC(ll$ I.A t:Jdr;:,1;.eJ~f%! CtfJN i;t,Lhi r:g,J Description of Proposed Project: Min; S+om~ Deve!opmmt ~ ~ Zone District(s}: GtviJ11;tra""1 /Genem) ,... Name of Owner of the Property: Wester/'\ fYlini s+om(jf: Lk. -Br1N& Snode ,_ Address: 9/B 0Wy R.o"'of 352 Telephone: ,... City: Rifle. State: c.o Zip Code: 81690 FAX: ,... Name of Owner's Regresentative, if any (Attorney, Planner, etc): SoQ~s I fnr;i'ae..ri"j IL c,, VMc.y N1Cml PE fbfic1poJ ', Address: <;oz Mcv"ri St S(Nfe.. tl.3 Telephone: {97olzo't'.-03J) ~ ' City: Cwfntocl!!)e State: CD Zip Code: 3.1623 FAX: lDlf._-0313 , STAFF USE ONLY , Doc. No.: _____ Date Submitted:. ____ TC Date: _____ _ , Planner: Hearing Date: ___________ , May 14 , 2 008 APPLICATION FOR A FLOODPLAIN DEVELOPMENT PERMIT FOR CONSTRUCTION ACTIVITIES PROPOSED WITHIN THE FLOOD FRINGE ASSOCIATE D WITH MINI STORAGE DEVELOPMENT WITH A LIMITED PORTION OF THE BUILDING ENVELOPE BEING WITHIN THE 100-YEAR FLOOD PLAJN Repr ese ntati ves: Sopri s Eng in ee rin g LLC 502 Ma in Stree t, Suite A3 Ca rb o nd a le , Col orad o, 816 23 John Peta is to EI Des ign Engin ee r Yancy Ni c ho l, PE Pro j ec t Ma nage r Applic ant: Bru ce Snod e 918 Co unt y Roa d 352 Rifl e, CO 816 50 Prope rt y Owners: Wes tern Mini Stora ge LL C 9 18 Co unt y Roa d 352 Rifl e , CO 816 50 Applicant: Bruce Snode SE Job No. 27246.01 May 14, 2008 Page 2 APPLICATION FOR A FLOODPLAIN DEVELOPMENT PERMIT FOR MINI- STORAGE DEVELOPMENT WITH A LIMITED PORTION OF THE BUILDING ENVELOPE BEING WITHIN THE 100-YEAR FLOOD PLAIN Property Owner Property Location: Western Mini Storage LLC 918 County Road 352 Rifle, CO 81650 The subject property is located in the northeast V. of Section I 0, Township 6 south, Range 92 West of the 6th P.M. in Garfield County, CO, west of County Road 311, directly north of Interstate 70. Request for Approval:(a) A Floodplain Development Permit for proposed construction ofmini- storage structures within a limited pmtion of the development area that is located within the delineated floodplain (flood fringe). The limited area of construction activities is associated with the south mini-storage structure, which is partially in the floodplain. (b) Approval of construction in accordance with Garfield County's Regulations regarding Development Permits and work in flood plains. SUMMARY OF REQUESTS The applicant is requesting a Floodplain Development Permit in order to construct the south mini storage structure onsite which encroaches into the delineated floodplain (flood fringe). The proposed development area onsite is on the east side of the site. No development or disturbance is proposed within the floodplain on the west side of the site. The proposed building is 3 feet above existing grade. EXISTING CONDITIONS AND FLOODPLAIN The site is shown on FEMA Flood Insurance Rate Map (FIRM) number 0802051092C for unincorporated areas in Garfield County, CO, revised August 2, 2006. The floodplain onsite is in the Zone A flood hazard area, where no base flood elevations have been determined. The floodplain was delineated based on a 1987 Floodplain Management Study of the Town of Silt, prepared by the USDA Soil Conservation Service (SCS). The site elevations and the FEMA FIRM mapping elevations are both referenced to the 1929 vertical datum. The 1987 SCS Flood Study is a global study of flooding and floodplain management in Silt. The study involves five tributaries to the Colorado River. Each tributary has defined areas and flow characteristics with dedicated drainage conveyance paths that route potential floods water under the Railroad, Interstate and State highway surfaces. The subject site is located between the described Seventh Street and 16th Street drainages and floodplain zones to the west and east respectively. The 100-year flood flows in each basin have been modeled in the study with resultant base flood elevations delineated. The study indicates that the I 00-year flood flows in each basin are conveyed through the defined drainage crossings. The box culvert conveyance tunnels have excess capacity to convey flood flows under the Interstate highway. The county road adjacent to the east property line defines and contains the flood plain on the east side of the Applicant: Bruce Snode SE Job No. 27246.01 May 14, 2008 Page 3 property with a delineated base flood elevation of 5434.2. The study indicates that the existing drainage conveyance tunnel under 1-70 has the capacity to discharge the flood flow from the basin. The model indicates the unrestricted 100-year flow through this conveyance flow path channel. The upstream cross section 1972.2 and the downstream cross sections 1972.1 and 1970, model this flow condition, showing that the full 381 cfs continues south under the freeway. See Appendix' A' for floodplain documents. The site generally slopes to the south west and is bounded on the west by the limits of the seventh Street drainage floodplain with a delineated base flood elevation of 5424.2 at the conveyance crossing. The south side of the site is bounded by a narrow strip of delineated floodplain extended to the toe of the Interstate embankment between the two floodplain drainages. This narrow strip appears to be defined base on relative elevations between the two defined drainage floodplain areas, highway embankment and the site. The lower grades within the strip appear to be associated with the seventh Street flood drainage floodplain along the north perimeter adjacent to the railway. Therefore we infer that this strip of land may at times be inundated with stagnate backwater. That would effectively drain to the west along the toe of the highway embankment to the seventh street conveyance crossing. The flood study does not indicate or report any cross basin conveyance of flood flow up to the 100-year event. The possibility exists that the strip may convey flood flows during an extreme event above the 100- year flood or ifan obstruction exists in the 16 1 " Street drainage conveyance crossing. However, based on the size of the Box culvert tunnel this scenario is highly unlikely. Therefore the proposed encroachment fill in limited area of the floodplain near the southeast corner of the site will not adversely affect the existing drainage patterns or flood conditions. The incidental drainage path will be maintained at existing grades between the site's fill slope and the highway embankment. Based on the available data regarding the two basin's flow conditions and the existing site conditions, we believe that only a small amount of backwater flooding will occur during the 100 year event in the delineated flood plain south of the site. The existing grades in the delineated floodplain indicate that incidental backwater flooding will be shallow with low receding flow velocity, as a result of rising flood water staging from the seventh street flood basin. No development or disturbance is proposed on the west half of the site. The Regulations with respect to the floodplain only require a development permit for "any use to be developed in the flood plain." Garfield County Zoning Resolution,§ 6.08.01. A portion of the Applicants' proposed construction and uses are inside of the mapped 1 DO-year flood plain. A portion of the proposed mini storage improvements are within the I 00-year flood fringe only; therefore the construction with appropriate flood proof construction and stabilization of any placed fill is applicable by definition under the Floodplain Regulations (6.02.10). USACE PERMITTING The proposed construction does not involve the placement of any structures or materials that will adversely affect the existing flood hydrology or impact any delineated wetlands. No disturbance of wetlands or existing floodplain conditions is proposed or applicable. Therefore no USACE permitting is required. CONSTRUCTION ACTIVITIES IN THE FLOODPLAIN Applicant: Bruce Snode SE Job No. 27246.01 May 14, 2008 Page4 Section 6.00 of the Zoning Resolution permits construction as discussed herein. Because a portion of the proposed improvements on the site is impacted by the I 00-year flood plain, Applicants herein address the flood plain regulations. The applicable maps identify that the south mini storage structure and a small portion of the next mini storage structure to the north are within the I 00-year flood plain (flood fringe). The construction activities in the floodplain are limited to the south mini storage structure and an additional 900 S.F. of the next structure to the north. The proposed construction includes an engineered foundation, walls, placement of structural fill materials typical for mini storage construction, and site grading down to the existing grade. The proposed south mini storage structure is setback 1 O' from the property line, and the finish floor of the structure is approximately three feet above the existing grade. The area of construction within the floodplain would slightly restrict the backwater storage area however adequate drainage conveyance area will be maintained for potential flood waters during events exceeding the 100-year flood. The building finish floor elevations will be 1' above the highest expected flood elevation. No storage or disposal of any materials is proposed within the floodplain. No utilities, water or sanitary service will be located within the flood fringe area. The finished construction will be resistant to flood damage. We would recommend that the south foundation wall for the south mini storage structure, near I-70, extend 4' below the finish floor of the storage units. APPENDICES The following documents are appended hereto: Applicant: Bruce Snode SE Job No. 27246.01 May 14, 2008 Page 5 Appendix "A" -Sheet I-Site plan, Sheet 2-Grading & Drainage Plan, 2006 FEMA Flood Insurance Rate Maps, 1987 SCS Flood Study exhibits. April 24 , 2008 APPLICATION FOR A FLOODPLAIN DEVELOPMENT PE RMIT FOR CONSTRUCTION ACTIVITIE S PROPOSED WITHIN THE FLOOD FRINGE ASSOCIATED WITH MINI STORAGE DE VELOPMENT WITH A LIMITED PORTION OF THE BUILDING ENVE LOPE BEING WITHIN THE 100-YEAR FLOOD PLAIN Re p resenta tives: Sopri s En g ineering LLC 502 Ma in Street, Suite A3 Carb ond a le, Colo ra do, 81 623 J oh n Petaisto EI D esign E n g ineer Ya ncy N ic ho l, PE Proj ec t Ma nage r Appli cant: B ru ce Snoad 9 18 Coun ty Road 352 Ri fle, CO 8 165 0 Propert y O w ners: Western Mini St orage LLC 9 18 Co unty Road 352 Rifle , C O 81 65 0 Applicant: Bruce Snoad SE Job No. 27246.01 April 24, 2008 Page2 APPLICATION FOR A FLOODPLAIN DEVELOPMENT PERMIT FOR MINI- STORAGE DEVELOPMENT WITH A LIMITED PORTION OF THE BUILDING ENVELOPE BEING WITHIN THE 100-YEAR FLOOD PLAIN Property Owner Property Location: Western Mini Storage LLC 918 County Road 352 Rifle, CO 81650 The subject property is located in the northeast Y. of Section 10, Township 6 south, Range 92 West of the 6111 P.M. in Garfield County, CO, west of County Road 311, directly north oflnterstate 70. Request for Approval:(a) A Floodplain Development Permit for proposed construction ofmini- storage structures within a limited portion of the development area that is located within the delineated floodplain (flood fringe). The limited area of construction activities is associated with the south mini-storage structure, which is partially in the floodplain. (b) Approval of construction in accordance with Garfield County's Regulations regarding Development Permits and work in flood plains. SUMMARY OF REQUESTS The applicant is requesting a Floodplain Development Permit in order to construct the south mini storage structure onsite which encroaches into the delineated floodplain (flood fringe). The proposed development area onsite is on the east side of the site. No development or disturbance is proposed within the floodplain on the west side of the site. The proposed building is 3 feet above existing grade. EXISTING CONDITIONS AND FLOODPLAIN The site is shown on FEMA Flood Insurance Rate Map (FIRM) number 0802051092C for unincorporated areas in Garfield County, CO, revised August 2, 2006. The floodplain onsite is in the Zone A flood hazard area, where no base flood elevations have been determined. The floodplain was delineated based on a 1987 Floodplain Management Study of the Town of Silt, prepared by the USDA Soil Conservation Service (SCS). The site elevations and the FEMA FIRM mapping elevations are both referenced to the 1929 vertical datum. The 1987 SCS Flood Study is a global study of flooding and floodplain management in Silt. The study involves five tributaries to the Colorado River. Each tributary has defined areas and flow characteristics with dedicated drainage conveyance paths that route potential floods water under the Railroad, Interstate and State highway surfaces. The subject site is located between the described Seventh Street and l 61h Street drainages and floodplain zones to the west and east respectively. The 100-year flood flows in each basin have been modeled in the study with resultant base flood elevations delineated. The study indicates that the 100-year flood flows in each basin are conveyed through the defined drainage crossings. The box culvert conveyance tunnels have excess capacity to convey flood flows under the Interstate highway. The county road adjacent to the east property line defines and contains the flood plain on the east side of the Applicant: Bruce Snoad SE Job No. 27246.01 April 24, 2008 Page 3 property with a delineated base flood elevation of 5434.2. The study indicates that the existing drainage conveyance tunnel under 1-70 has the capacity to discharge the flood flow from the basin. The model indicates the unrestricted 100-year flow through this conveyance flow path channel. The upstream cross section 1972.2 and the downstream cross sections 1972. l and 1970, model this flow condition, showing that the full 381 cfs continues south under the freeway. See Appendix 'A' for floodplain documents. The site generally slopes to the south west and is bounded on the west by the limits of the seventh Street drainage floodplain with a delineated base flood elevation of 5424.2 at the conveyance crossing. The south side of the site is bounded by a narrow strip of delineated floodplain extended to the toe of the Interstate embankment between the two floodplain drainages. This narrow strip appears to be defined base on relative elevations between the two defined drainage floodplain areas, highway embankment and the site. The lower grades within the strip appear to be associated with the seventh Street flood drainage floodplain along the north perimeter adjacent to the railway. Therefore we infer that this strip ofland may at times be inundated with stagnate backwater. That would effectively drain to the west along the toe of the highway embankment to the seventh street conveyance crossing. The flood study does not indicate or report any cross basin conveyance of flood flow up to the 100-year event. The possibility exists that the strip may convey flood flows during an extreme event above the I 00- year flood or if an obstruction exists in the l 61h Street drainage conveyance crossing. However, based on the size of the Box culvert tunnel this scenario is highly unlikely. Therefore the proposed encroachment fill in limited area of the floodplain near the southeast comer of the site will not adversely affect the existing drainage patterns or flood conditions. The incidental drainage path will be maintained at existing grades between the site's fill slope and the highway embankment. Based on the available data regarding the two basin's flow conditions and the existing site conditions, we believe that only a small amount of backwater flooding will occur during the 100 year event in the delineated flood plain south of the site. The existing grades in the delineated floodplain indicate that incidental backwater flooding will be shallow with low receding flow velocity, as a result of rising flood water staging from the seventh street flood basin. No development or disturbance is proposed on the west half of the site. The Regulations with respect to the floodplain only require a development permit for "any use to be developed in the flood plain." Garfield County Zoning Resolution,§ 6.08.01. A portion of the Applicants' proposed construction and uses are inside of the mapped 100-year flood plain. A portion of the proposed mini storage improvements are within the 100-year flood fringe only; therefore the construction with appropriate flood proof construction and stabilization of any placed fill is applicable by definition under the Floodplain Regulations (6.02.10). USACE PERMITTING The proposed construction does not involve the placement of any structures or materials that will adversely affect the existing flood hydrology or impact any delineated wetlands. No disturbance of wetlands or existing floodplain conditions is proposed or applicable. Therefore no USA CE permitting is required. CONSTRUCTION ACTIVITIES IN THE FLOODPLAIN Applicant: Bruce Snoad SE Job No. 27246.01 April 24, 2008 Page4 Section 6.00 of the Zoning Resolution permits construction as discussed herein. Because a portion of the proposed improvements on the site is impacted by the 100-year flood plain, Applicants herein address the flood plain regulations. The applicable maps identify that the south mini storage structure and a small portion of the next mini storage structure to the north are within the 100-year flood plain (flood fringe). The construction activities in the floodplain are limited to the south mini storage structure and an additional 900 S.F. of the next structure to the north. The proposed construction includes an engineered foundation, walls, placement of structural fill materials typical for mini storage construction, and site grading down to the existing grade. The proposed south mini storage structure is setback 1 O' from the property line, and the finish floor of the structure is approximately three feet above the existing grade. The area of construction within the floodplain would slightly restrict the backwater storage area however adequate drainage conveyance area will be maintained for potential flood waters during events exceeding the 100-year flood. The building finish floor elevations will be 1' above the highest expected flood elevation. No storage or disposal of any materials is proposed within the floodplain. No utilities, water or sanitary service will be located within the flood fringe area. The finished construction will be resistant to flood damage. We would recommend that the south foundation wall for the south mini storage structure, near I-70, extend 4' below the finish floor of the storage units. APPENDICES The following documents are appended hereto: Applicant: Bruce Snoad SE Job No. 27246.01 April 24, 2008 Page 5 Appendix "A" -Sheet I-Site plan, Sheet 2-Grading & Drainage Plan, 2006 FEMA Flood Insurance Rate Maps, 1987 SCS Flood Study exhibits. I I I •• •• I I • I I I I I I • 9~ II - .... . -~- FLOOD PLAIN MANAGEMENT STUDY TOWN OF SILT COLORADO Prepared by the U.S. Department of Agriculture Soil Conservation Service · Denver, Co 1 or ado fn .cooperation with the . Colorado Water Conservation Board Town of Silt and Garfield County, Colorado July 1987 ·'l.;c-_,,. 5420.8 x -·· ---... I I ' ----1 5422.3 x \ \ )( "' " "' "' 0 -... --:;:- · · ·~ b=='.· ----=="-= --... ' ' \ \ LEGEND FLOOD PLAIN LIMITS SECTION CONTINUED -+.-.. ·-+.--.. 8 ~Cent tr Lont '\ Station In 100 fl . 0 from lower study limo! CENTER <) POINT 100 YEAR FLOOD ELEV. --5 - 2 - 80 --- C·69 INDEX NUMBER FOR COLORADO RIVER MA PPING PROJECT COOROINATE SYSTEM IS THE MODIFIED COLORADO STATE PLANE COORDINATE SYS TEM , CENTRAL ZONE, LAMBER T CONFORMAL CO NIC PROJECTION . THE FOLLOWING (USC 6G ANO USGS) TRIAN GULAT ION STATIONS WERE USED : ORY HOLLOW X• 1,395,770 .68, Y•613,0l3.61, CASTLE X•l,432,094.81, Y•623,300.73, ANTLER X •l,371,760.95 , Y•630,478.31. BASIS OF VERTICAL CONTROL: us e SGS AN O USGS. SEA LEVEL DATUM BASED ON THE FOLL.CfN ING BENCHMARKS: RIFLE ELEV. 5 319.19 9, NEW CASTLE ELEV.5747.82. TOPOGRAPHY COMPILED BY PHOTOGRAMMETRIC METHODS FROM 6" CFL VERTICA L AERIAL PHOTOGRAPHY TAKEN JAN.12, 1983. COMPILE D 8Y SELL M APP ING CO., 500 KALAMATH ST. OE NV ER CO . REVI SIO N 1..COEHO (2} MAP SHUT NU'-"9ER DATE (1 4) fl: 92 .-i-;;, w T6S . I''' BY /\ U.S. DEPARTMENT OF AGRICULTURE V SOIL CONSERVATION SERVICE FLOOD PLAINS FLOOD PLAIN MANAGEMENT STUDY TOWN OF SILT 200 SCALE IN GARFIELD COUNTY COLORADO 0 zoo IN l4 400 600 FEET TABLE 1 FLOOD FRE~UENCY-ELEVATION AND DISCHARGE DATA * **********•*********************************************************************•**************************••••• *Cross *Stationing* Identification *Stream Bed* Crest-Elevation and Peak Discharge c.f.s. • * Section * from Mouth * * Elevation *********************************************•******* • Design-* * * * 10-Year * 50-Year * 100-Year * 500-Year • * nation * Feet * * Feet * Flood * Flood * Flood • Floo d * **************************************************************************************************************** * 513 # * 0+00 * Colorado River at * 5417.7 * 5426.7 * 5426.7 * 5426.7 * 5426.7 • * * * Si x teenth St Watersh * * 20100 * 2 0100 * 20100 * 20 1~0 * * * 1970 * * * * * * * 1972.1 * * * * * * 1972.2 * * * * * * 1974. l * * * * * * 1974 .2 * * * * * 1976 * * * 1978 * * * 1980 .1 * * * * * * * * * * * * * 1980.2 * * * * * * 2980 * * * 2982 * * * 2984 * * * * * * * * * * * 5+20 6+50 7+98 19+78 20+38 21+53 2c.+00 26+58 27+08 29+83 34+03 38+03 * * * * * * * * * * Si>:teenth St Watershed Interstate 70 * * * * * * * * * * * * * * * * * Denver & Rio Grande * • Western R.R. * * * * * * * * * * * * * * * * * U.S. Hilghwa!:f 6 Main St * * * * * * * * * * * * * * * * * * * * * * * Lower Castle Valley * * Ditch * * * * 542 6.9 * * * 5430.5 * * * 5430.5 * * * 5438.0 * * * 5438.0 * * * 5438.0 * * * 5443.8 * * * 5447.3 * * * 5447.3 * * * 5453 .5 * * * 5459.0 * * * 5469 .0 * * * * 5429 .1 * 96 * * 5431. 7 * 96 * * 5432.8 * 96 * * 5440.2 * 96 * * 5440.4 * 96 * * 5441.4 * 96 * * 5444.1 * 96 * * 5449.8 * 96 * * 5449.9 * 96 * * 5454.5 * 60 * * 545~.9 * 60 * * 5469.2 * 60 * * * 5429.2 * 279 * * 5432.7 * 279 • * 5433.8 * 279 * * 5441.7 * 279 * * 5441. 8 * 279 * * 5441.9 * 279 * * 5444.2 * 279 *· * 5450.1 * 279 * * 5450.3 * 279 * * 5455 . 1 * 178 * * 5460.3 * 178 * * 5469.4 * 178 * * * 5429.2 * 381 * * 5433.0 * 381 * * 5434.2 * 381 * • 5441.8 * 381 * * 5441. 9 * 381 * * 5442.0 * 381 * * 5444.3 * 381 * * 5450.2 * 381 * * 5450.4 * 381 * * 5455.3 * 237 * * 5460.4 * 237 * * 5469.5 * 237 * * * 5429.2 * 657 * * 5433.5 * 657 * * 5434. 9 •· 657 * * 5442.1 • 657 * * 5442.2 * 657 * * 5442 .3 * 657 * * 5444.5 * 657 * * 5450.3 * 657 * * 5450.7 * 657 * * 5455.7 * 397 * * 546 0.7 * 397 * * 5469.7 * 397 * * **************************************************************************************************************** .. * Flood elevations pertain to the primar!:I channel and usually remain constant i n a lateral direction across the flood plain. However, flood elevations in 'the outer portions of ·a cross section ~ay differ from · the primary channel due to road crossings, upstream diversions, etc. 1 · Discharge in Colorado River at 25 year frequen~y ~ Table Page 5 Divided flow e x ists with 2/3 of discharge at this location .. - -: NOTES TO USERS Th.1 INP II IOt '°"t in H~teMg ~ N1 \IONI flc>ocll ~\If"'<• "°OO'IJI\.. It doo flOt rcun tNv 'dtnt.IY .. ""' •~ct 10 noo.~. otl1k~ fretr1 llc•l •*'-9• '°"'cu o1 Mltlt '"'· The ~' ..,.., "'Po•""" tNllM bl coN1ll l.td f0tt"U•bltvodt tfdtf"6dftiOt1-1r.cood h1uul "''•'""ti0ft. To obt1irl moll dttdtd iflfor~•l4n in tttN wMrt l •M ,.._. IUn t tlM f&fh ) tf'ld/., ,. ..... ,,. l\tv• bun detetm.ne<I, ~Ill MICO!,WIR41d 10 'ON l.ll l tt-c flood "•lilu M'4 A>odw•1 01t1 Ub'..!1 un11:ntd w.uwi '"' Flood h11r· tr\C.I St~ IFISI IH'Ott tl\.lll a«omotlliu 1N1 FtAM. U.ttt ·~·d be I W&ll INI IFC1 11lown Otl .,,. AW llPl'UVll IOUl\dtd wholt·IOOI l 'IVll.OM. TN11 IF[I I ll inttl\ff.d IOI f10od iNUltllC• r1t1ng P-l'potu orlfy tl"ld 1N1111d Nit bt ~d Hll'llHi.IO\l'c1 o l llood 11tv11ioninJ0ttNtlo n. ""'°'dl.~y. ll.>od 1'1v.1.on dtt. O'IHl'lltd Jn Ille 'IS l hcv'd bt lrti h ed in colljo.rnctio11 Wilt\ lht FIRM llM' purpou1 ol co rwivuctton 1n4/0t tloodplt in mt,.,;tmtnL CMn .. I HI Flood UtYldtft l1Fh1 t l'\o'olon Ot1 thl-1 t110 t,DAo ol\ly i.M· """' ol 0 .0' N1t.on1I Gud1c)c Vt •tiu l Dttl.lft'I INGVOJ , Ute/I or ~ FlflM 61\o\lld bt ....,.,, INI uulll llood tttvt t>ont 11'11'1' .... b4 P'OYldtd 11'1 lN ~l!y ot IV!tw1t1r Vtw1tioM t.lb'• It\ ltlit ,.iOod lntt.111 110 $\l,ldy "P<I" IOf tJlb c.,-,im\Hlftv. 0.Y~ ahcwn ~ ,,.,. Svlnrnetv ot Strtw1:1t f:e.,etcone t.1b!t: •l'lol.i'd bl w ed l0t toftlWC:tioil. 1114/or f'lffdpl-"' tt'lt lll ;f!'l'ltnt °""~ wt\t'I tt-.'(•I I ~O'lln"'4 1°t'l'•~l'llfhoW"O"\l".lflftM. lol.Nllllu ot IN 1'oo4Wlyt 'lffl't coml)UUd II c rOA HU•Ofl& end ~11~0 11.td bttwtltl "°" nct:ont. TN floodw•YI WI.ft bued OI\ l'lydft.lic c.oMldttlU0/11 with ltfl!d W rtqv-..,.e11t1 of IN NalioNJ F".ood '"'"""'' Pr0911m. F".oo4w1v Wld\tll 1.nd otn.t ptrWol'lt floodway 6111 .,, P"Ow4ded h '"" noOd INl t.lfl "(t ltl.Mttftpon lorth.1~1 :Sc"4M. C.r1u1 11111 nol '" 8PtCil! f lood Hln ·d Ar111 m1y tit prol1 tt1d by fl•od •ontr°' 111\!ct .... u . lltftt lo Section 2.• ·~odl"rotlCbO" t.eu111ru• of tht Flood INt.lf•nc• $1\H!y 11 port I« ifllorm1t>011 Of1 flood COtllJOI lll\iClllfll ll'tlhltiiir•dictli>n. Tri1 iwo)ldJOI\ t.1Ud ill lN 9'fl)lfltion ol llU rlll P ii UniVU N I T11nver11 MtlCl\01 lUTMI Jo."14; 1l. Th4' l\oflumal ...... ~ NADU, Gll S1110 apht101f. O.t11r111c11 ill dtt\.111'1, 1pP\1rci\d, IWOJKIOoll or UTM 10NI !Ai d ill \ht Plod\.lcf>Ofl Of flllMi IOI ed,Kllll jl.lfildict:ont IN'!' IN vlt in I~ po1lt0/lfl diff1111'1Ct1 i,.. l'l'llP ftlMH wou jurltd\ttio,. ~"'""'· nwiu diUtrll'l(fl dol"Ot 1H1Ct lll.1 ecc1111cvol ll\f filtM. Aood 1'.11111lof11 Ofl .,-. '"IP t it 11!11tfl(td \0 h N•liMt l GtoOtlk: V1,li(1l 0 1111tn of t t21. TMn l'loocl 1'1v1bOl'll ll'MI bl etm,lrt d 10 1twcl\lt1 tJ'ld f'O~ l ltvttloN llllft"Ct d '°d'il ll"'I .....iJ«I "-"'"'-l0t W01fNlllOll r-sarf-.1'9 c•nw1>0t1 betwMn thl Natior111 Godtt.c V11dctl 0 1twm of \Ill N'ld ""' Ntotih M.ll'lct 'I v .. 11e11 b1tum of 1111. """ N Ht \ltftt l G•Ht1'C 5'.nry Wt*• 1 1 --""·"'' fl(t.tl .fOV Of COftatt tM fqtJotit l c..offtie: lvtwty tt tl'lt lt lowlno tddrm : SQ1ti-ellt4if111r.c:1Svar.emOll''otlc>n H1Uon1I Gt0dt lk: '"'"'v. HOM Stve1S94''"9M1troC.nte1 1J l i (lll•WHI H~w ly Sk.·11SPf~,tl.11"°"nd 2 01 10 \IOll 7U 32•2 To ob11lnc1.1111 n1 1ltV1liofl, duc11f"lo,., 1ndlt:1! location illfoun,11\lon l01 Mnch m1rka ll'tclwn on lNI lf!O, pluu coMI" the lrifo1rn1ticin St1Vc.11 llll'tth ol IN H1tiO!lfl Otodttl' SU,...tY 11 IJ01) 711·1142, or vb t tnflf w1b1!11 11 WWWl'l;t ."OU tOV, .... IMP il"llOlrlllton l"IOWn .., th'.1 "'™ w .. proy"r414 .. diO t.i IOl'!Nl by u.s a.ci1.,rc.i lt.lfvtv O\eitel Orihophcito Outdrtnelu prHfl.<N 1t • •:•lt ol 1:1)0001tofl'lpl'lo\OQ•t P"IVcl.ii$Stptl<""k20, 11Uo1ltlt1. c.,,_. .. hft1 IMwn on tl'll mtP "' teMd Ol'I 1t'4 ltltlt Hit l vt '•~ 11 die lflnll ol ll'All u llon. IKIWM cMnQe• M lO IMHlllON Of •·•-wwxttiOM fftly 1'11v1 OCC.lltl'td 1ft" tH• ""P wn ~di. ""0 Wltl Nuld toni..tl l11'9'0ptttltC~ty oH.eie'1 to ,·arofyCll"l..,,(.OfPOflll ~IOC1t4N1. f'ltuo 11111 to IN up1r1t11V ptol'Hld Pi111p tndo1 for 1n civt t't"ltw tl'ltP tl'IO~SI the l1 yci ~ el IMPPll'llll fo<ttlo:t Jl.w•td'IC liOn. An tccornPtnylrit flood '"'t.1'•11C• SW<fv 11i>0rt, l41ltrl 01 M•P ~vl1Jon Of L11ttt1 or Map Arn1ndl'l'l1n1 11V-1itlg POttioNI of thl1 H~•1, and 6g;l11t w11i..-ia ol t/\11 PANn may bl 1val!1ble. Ccinttcl 11'11 flMA Mep l11n1c. C1rU1t '1 :-oc:~~.i::7~:;"'~';_~ tJ'ld lntttntl tdd111t fOI' lflfM11tt0t1 Oii ti itltltd "'°"'· fOO.JH H16 fAX: 100-3H·IUO .--.......,..-. H ,.OU N vt •Hd 9"1 ~ dlh '''"' O< QtH.StlON C-"Cl ltloflO lht Htt,.,-11 f'1ood r .al#tncl Pr•t1~ lrl "'*,.· plcn1 u1 1·1 77.fl MA·MAPII177 UI HJnorv<a.1Nn MA""·tM.11 1twww.f11111.p. Tllll fNP ••nut&,..,.,, detliltd ~ l.IP'~I• '"""' c /'\f.nnel cont1;1111 b0tll tN" thoH •Ntw,. • ., tNI pr1Ylowi flllM lor lh'• ;....lfalotl. Tllt ftoodD'I H etld Roodwt '(I !Mt Wfll ti1111f11Jd from "" Ofl'l';0\11 F~ ,,..v lllvt bUl'I td'iwted to COtllOll'l'I to thcH ntw ltrU rrt cNIN'lel COflf>1ur•tiol'\I. M • rt1vl t, IN f lOod Prohl u 1tld ~IY b •tt 11b1t1 Ir'! ~ flHd lnt\llll'ltt S1"'dy 11po11 mer 11lloct w u rn cJ't•MCI criien.;u 11\tt dilf1r lrott'I wt-..1 • IMwn0ti NM1p. LEGEND SPEClAl FLOOD HAZARD AREAS SUl.JECT TD iNUNOATION BY THE 1" ANNUAL CHANCE FLOOD EV EHT n..1,. -..i-.-hCl'dooo-v-...._ ••"'-_,.,,....,.,,._., • .,.,..., M Ml • '"' ~ ......... _ _.M llt tl>(._..N loo'"' p...,. , . ...,. The .,.._ :;:!'iJ•,f,!:~~.:r.-= 1:. -:r.·r:t.,tv ::_ a m.°"v."'::-J~M •.:: ""4l ..... 11""'"P..t•#l•M-9'tN1Uilt> ..... l 1'1to*""""'~,._,., t ONIJ. .... ~lk>-'•'watlw>IM•tl'\Nolll. lOflll AI ... ,ftood~.v1tlor'ol .. 1.,,,.....,,., lOflll AH 1lood _,u,. d I la J '"' l-.itl!l1 MMt Gf •iMnel: N H '.9111 ...... ~1on1 dd•rT"·fld. t ONIA.0 floG• idtC>lrll d ' ti a ,.., ""'""' ....... "'" on "°""' tlfflk'll; ::~~ Nl•minff. '"' •111 ol """""" f _, "-""'• ...ioci\IM tONI ~ ~ .. « ~1 tood 1w:11• ftt_:., flltl..:ii.d frr1m flt lti ll'W'UI! :=:flld~:w ..... ~'!"'..:"~~ ::::...-:,:: :.~...:~ ..... 11tt111H a."'"""' 1'-lltft ~-0.. 1 '11. ~ cNtlU Cl< ... t.t rt ............ t ONIAN N u .. M ,..oit<:\H ,._ I'll. .,...-.,,.._, ...., ....-., t '..tll~ ~ ... tac\lan ..,.:.roi ..... --~ ........ , .... ....,..._, .. -... t Oflll V C~ llkloof r.ir.o . ...,_ ~ "'1•• '"'"' -->.; tit NH ~ ................ "'""'"" t OHIVI C.-ulllaM 111t• wt!}! .,.1oo1ry ,..,,.,.1-..w ICldonr. ..,, kM r/..-vltlllllt .............. ~ FLOOOWAY AREAS IN ZONE AE :!:t ",.~W.,..,.!,~•oot.!1'!:!";(" =t1~ f~t:, ~!..~~":'i::..!: .W.'-'ltT.i N:lrU11 .. lnfttcid~'""d'>l1. rfa~@ OT HER FLOOD AREAS ~IX Ar,.. M 0.3"' ....,.,_. ~ r...li •Ml tl 1'6 ...... ~ .,,_ floool ~-=.~~· :.:-:i=~ ':.,• t!.!llto1t~"t:: ~·;;: D OTHER .AREAS l ONI X ~-<1.t•IU\M tebo°"~NOJ tii..,.,.,..._. ..... ,"· ZOftlO ArM•ft~r.-.Naiul1ar1 "*-...... """"' .. 11t• ~ COASTAL BAR RIER RESOURCES SYS TEM ICBRSI AAEA S ~ OTHERWIS E PROTECTED ARE AS <OP.A.ti CW111 .. 11111or.t.1 111Mtf!Mly lo¢tttd wifV!" idjlC«lt ••lttc"ll ~ tfua1111u .... __ ,,,,.__ m .H7t ,,. ........ d'I-~'" ......... "' 0.2',,,,_"~n.odpl .... NtM.try flood,."VboliNl•Y z-o~..., Cf"'"O'A ~tr'r a..n.o4 ~lt11~•~"1v1l!G"•I011' ·-""' e.v.-. """' ....... _,_ wu.k ,.,,... •Wtnhl HI' 'M•IMWll""'Kl"""O~V111tk.ltD1h.o9l .. l l U ©---© ®·····@ 421600'M eooooon OXHIO )( t M U Cl1e9 .. _..,., .. r9ftf""'°" te,... Hot1h ~ Dmn of l lUUU.O lll 1DOD-fnot111 UrWrMITfll'llV«H MMu~..w w ........ -1.11 MAl'Ml'OMTOAY T-11 lih, ,..,,. H11. 1>1 ....., 111'1 ..,,.._ 14 CO lllU o,i,.. .... ...,,,.,Hf•ww.tl/llly,"l'llllllll't """""j INTIA&.IODfTVICAllON AA.YJS,1111 ROOO HAZAl'O 90UfCINt'I' "'N llllVllOf'O .. ..... ROOOlfo1UM.N4;(AAU """1n1cnvt Alt'll.1,1111 ROOOl!ffUlllAAC( IUT(M» "IY!.llON'I """"" '· XIOt: • ......,, _,..,," Wtt. M _., No t.oM ..,.,........_ "' Mo! •o.dl!l •N-4 b Ull ........ .,....,.. ~· ""'°"' ""'"' ....... ""'*• ..... ,..., -· """' .......... , .. ~ . ..-.""""''.-. Te 4'1•mN • ,....,. NI-• It t n h W. h "• ~. -llot '°"' n...-• AO"" Ill~· ... ~111o11M f1roGd .......,_"'•"""ti ltOOi &Jl·NJO. MM ICAU r • IOO" l~" PANEL 10921 FIRM FLOOD INSUR ANCE RATE MAP TOWN OF SILT, COLORADO GA RA ElO COUl'ffY PANEL 1092 OF 1125 CIU MAP .. OU 'Oii UW ,AXfl l .. O'OUTI "'"' MAP NUMBER 080223 109 21 MAP REVISED: AUGUST 2, 2006 Fcdcnil Erncracnc..')' M:magcmcnt Agc rx:y ) LEGEND FLOOD PLAIN LIMITS CONT INUED -+.-···-+.-··· D, ~ CMttr Lont ""'\ Station In IOOtt. VER TICAL CO NTR OL PHOTO CENTER GRID POI NT 0 from lower study limit <) 100 YEAR FLOOD ELEV. --5 - 28 - 0 --- C·69 INOEX NUMBER FOR COLORADO RIVE R MA PPI~ PROJ ECT DATUM BASED ON THE FOLLOWING BENCHMARKS : 0·156 ELEVATION ~~i~filf:f~~~;=:::::~~~~~~~;~;~~~i~~i~~ij~~~~;~i~~~~~~~==:=~~~; f ~~~~~?~~~~~~,~~~~~~ii!li~l!llliili!~~~-~--6192 .2B4. 4870.74PS-ELEVATION 4869.860. PREPARED BY ANALYTICAL 'I SURVEYS, INC. 416 7 SINTON ROAD, COLORA DO SPRINGS, CO. 8 0907. SHEETS 3,4 ,5,8 ,9,12,13,14 ANO PARTS OF 2,7,10,11 COORDINATE SYSTEM IS THE MODIFIED COL OR ADO STATE PLANE COORDINATE SYSTEM , CENTRAL ZONE, LAMBERT CONFO RMAL 5 4 20.8 J x t-- NOTE : )( I \ -~ \ I )( -·· "' .. I ·" 5:J •· .. a, ~ ... <> .. N <> 0 FL.fX)[) '· ', "SEC1ION . CONIC PROJ ECTION . THE FOL LOW I NG (USC 8 G ANO USGS) TRIANGULATION STATIONS WERE USED : ORY HOLLOW X•l,395,770.68, Y•613,0'53 .61, CASTLE X•l ,432,094.81, Y•623,300.73, ANT LER X•l,371,760.95, ¥•630,478.31. BASIS OF VE RT ICAL CON TROL: us e 8 Gs ANO USGS. SEA LEVEL DATUM BASED ON THE FOLLOW ING BENCHMARKS: RI FLE ELEV. 5 l l9.199, NEW CAS TLE ELE V.5 747.82. TOPOGRAPHY COMPILED 8 Y PHOTOGRA MME T RIC METHODS FROM 6" CFL VERTICAL AERIAL PHOTOGRAPHY T AKEN JAN.12, 1983. COMPILED BY BELL M APPING CO., 500 KAL AMATH ST. DEN VER CO . RtZ W~tlW T 6S -,.,.S REV ISIO N DAT E BY U.S. DEPARTMENT OF AGRICULTURE ~ son. CONSERVATION SERVICE FLOOD PLAINS FLOOD PLAIN MANAGEMENT STUD Y TOWN OF SILT IN GARFIELD COUNTY COLORADO 200 0 200 4 00 600 SCA L E IN FE ET F 14 ... .. .. .. ----- -- ----.. Ill~ TAP0LE 1 FLOOD FREQUENCY-ELEVATION ANO DISCHARGE DATA * ***********************************************************************************************************•••** * Cross * Stationing * * Section * from Mouth * Identification *Stream Bed* Crest-Elevation and Peak Dis~harge c.f.s. • * Elevation **********************************•****************** * Design-* * n ation * Feet * * * * 10-Year * 50-Year • 100-Year * 500-Year • • Feet * Flood * Flood • Flood * Flood * **********************************************************************************************************••**** • 513 # * 0•00 * Colorado River at * 5417.7 * 54 2 6.7 • 54 2 6.7 * 5426.7 * 54 ~A .7 * * * * East Watershed * • 2 0100 • 2 010© • 20 100 * 20 100 * * * * * * * * * * * * * 1970 * 1972. 1 * * * * * * * * * 1972.2 * * * * * 1974.1 * * * * * * * 1974.2 * * * * * 1976 * * * 1978 * * * 1980. 1 * * * * * * * * * * * * * 1980.2 * * * * * 1982 * * * 1984 * * * 1986 * * * * * • * • * * * * 5+20 6+50 7•98 19•78 20•38 21+53 26•08 2 6+58 2 7+08 34+58 39+88 44+88 * * * * * * * * * * * * Intel"state 70. * Denver & Rio Grande * Western R.R. * * * * * * * * * * * * * U.S. Highway 6 Main St * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Lower Castle Valley * * Ditch * * * * * * * * * 5426.9 * * * 5430.5 * * * 5430.5 * * * 5438.0 * * * 5438.0 * * * 5438.0 * * * 5443 .B * * * 5447.3 * * * 5447.3 * * * 5450.0 * * * 547 1.5 * * * 5487.0 * * * 54 29.1 * 96 * * 5431. 7 * 96 * * 5432.B * 96 * * 5440.2 * 96 * 5440.4 96 * * • * 5441.4 * 96 * * 5444. 1 * 96 * • 5449.8 * 96 * * 5449.9 * 96 * * 5452 .4 * 59 * * 5471. 9 * 59 * * 5487.4 * 59 * * 5429.2 * 279 * * 5432 .7 * 279 * * '5433 .8 * 279 * * 5441. 7 * 279 * 5441.8 ';!.79 * * * * 5441 .9 • 2 7 9 * * 5444.2 * 279 * * 545 0. l * 279 * * 5450.3 * 2 79 * * 5453 .3 * 162 * * 5472. 1 * 162 * * 5487 .6 * 162 * * 5429 .2 * 381 * • 5433 .0 • 3 8 1 * * 5434.2 * 38 1 * * 5441. 8 * 381 * 544 1. 9 381 * * • * 5442 .0 * 381 • * 5444 .3 * 381 * * 5 4 '50 .2 * 381 * * 545 0.4 * 381 * * 5453.6 * 2 15 * * 5472 .2 * 2 15 * * 5487 .7 * 215 * * 5429.2 * 658 •· * ~.433_ 5 * 658 * * 5434.9 * 6'58 * * 5442.l * 658 * * 5442 .2 * 6 58 * * 544 2 .3 * 658 * * 5444 .5 * 658 * * 5450 .3 * 6'18 * * 5450 .7 * 658 • * 5454 .2 * 352 * * 5 4 72 .4 * 352 * * 5487 .8 * 352 * • ************************************************************************************•************************•** * Flood elevations pertain to the primary channel and usually remain constant in a lateral direction across the fl ood plain. However, fl ood elevations in the outer portions of a cross section may differ from th e prin1.;ory channel duP. to road crossings, upstream diversions, etc. ~ Dischal"ge in Colorado River at 25 year frequency Table Page Divided flow exists w ith 2/3 of discharge at this location "Ill