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HomeMy WebLinkAbout912 WOOD ST. (PATEROS CREEK) - MOD - MOD120004 - REPORTS - MAPS/GRAPHICS (3)912 WOOD STREET LOCATED IN THE SOUTHWEST QUARTER OF SECTION 2, TOWNSHIP 7 NORTH, RANGE 69 WEST OF THE 6th P.M. COUNTY OF LARIMER, STATE OF COLORADO ® NORTH PROJECT i�4fg . PFATK?N �'vlGnm _ MAP P LEGEND. Li1�S+1 ) , LLfi i , H -- - oz' a t. cs )- ...r. »Iwrxxcl soon n FIELD SMp Y BY: BENGNMARRS' FEMA 0.EFERENCE: G F "'inr.'•'"' res a"" w X w�rria"rlwuwithrvii�'Fe`hii�ia it N O " O twirKrm rceun v ru¢ n.n " r[ r,�r,r LL LEGAL DESCRIPTION rri eunrr »�,q .UA P mwWa. <lnxunr �w r ai[\r yi»w >ps ii wr e "G>lrrwnW.m•.a;;;�..'....��ae.L.aL,.r.,.,. FLOOC ...._".,...,�.... ,er,nn •'mlat'o arwn bi,•i'.`vu,r PERMIT NORTHERN ENGINEERING 912 Wood Street Although the proposed fill placement by itself is not expected to impact the floodplain hydraulics, the land owner does intended to apply for a LOMR-F with FEMA after the fill has been placed in order to revise the mapped flood fringe. The land owner realizes that even though this will remove the floodplain from the fill area, any future structures in this location will be required to have the lowest floor elevation (including basements), HVAC, ductwork, electrical, and other mechanical equipment elevated two feet above the 100-year flood elevation. While all of the fill and excavation proposed with this Larimer County Floodplain Development Permit resides in the FEMA regulatory Poudre River floodplain, a portion of the property also contains the West Vine floodplain (a City of Fort Collins regulatory floodplain). Both floodplains have a defined floodway. This permit proposes no activity within either floodway. To ensure this, both the Poudre River and West Vine floodways will be staked in the field adjacent to the construction area to ensure that no work occurs in the floodway. The proposed earthwork activities described above are allowed within the FEMA regulatory 100-year flood fringe for the Cache la Poudre River. Due to the conveyance shadow cast by the upstream trailer park, it is not anticipated that there will be a significant change to the effective floodplain boundaries or base flood elevations as a result of the excavations or fill. Please feel free to contact us if you have any questions or require additional information. Sincerely, NORTHERN ENGINEERING SERVICES, INC. Nicholas W. Haws, PE, LEED AP Colorado Registration No. 39767 Copies to: Eric Tracy, PE, CFM Marsha Hilmes-Robinson, CFM Gino Campana Attachments: Floodplain Exhibit References: Aaron T. Cvar, PE Colorado Registration No. 36271 Larimer County Engineering City of Fort Collins Floodplain Administrator Sidehill Investment LLC 1. Federal Emergency Management Agency (FEMA), Flood Insurance Study for Larimer County, Colorado and Incorporated Areas. Volumes 1-4, Flood Insurance Study Number 08069CVOOI B (2008). 2. FEMA, National Flood Insurance Program (NFIP) Floodplain Management Requirements: A Study Guide and Desk Reference for Local Officials. FEMA 480 (2005). 3. Hydrologic Engineering Center (HEC), HEC-RAS River Analysis System; Hydraulic Reference Manual. Prepared for the U.S. Army Corps of Engineers, Version 4.1, CPD-69 (2010). Larimer County Floodplain DevelopmINermit 3 NORTHERN ENG NEERING 912 Wood Street The Hydrologic Engineering Center (HEC) of the U.S. Army Corps of Engineers (USACE) defines ineffective flow areas as, "...areas of the cross section that will contain water that is not actively being conveyed. Ineffective flow areas are often used to describe portions of a cross section in which water will pond, but the velocity of that water, in the downstream direction, is close to zero. This water is included in the storage calculations and other wetted cross section parameters, but is not included as part of the active flow area. When using ineffective flow areas, no additional wetted perimeter is added to the active flow areas." (HEC 2010) lneffectve Ineffective Area Limits of Flood Plain Figure 1 — Example of where ineffective flow areas are often located within a typical floodplain (HEC 2010) Since ineffective flow areas do not actively convey water in the principal downstream direction in a steady-state hydraulic analysis, activities initiated in these areas will not be shown to cause any change to water surface elevation, flood volumes, or flood flow velocities in a hydraulic analysis. Therefore, the ground topography can be modified and other flood flow obstructions can be established in ineffective flow areas without raising the water surface elevation, and without forcing water onto upstream, downstream or adjacent neighboring properties and infrastructure. By definition, fill can be placed in such ineffective flow areas without obstructing any further conveyance and without changing the base flood elevation (BFE), flow velocities, or floodplain boundaries. As stated above, the area being filled with this Floodplain Development Permit was excavated by the previous land owner for the purposes of selling gravel. The depression shows up as flood fringe on the current floodplain mapping because the date of the aerial topography was after the area was sourced for gravel. In fact, it somewhat resides in the conveyance shadow of the existing trailer park, which is located upstream to the west/northwest at a higher elevation. Larimer County floodplain Development Permit 7 NORTHERN ENGINEERING ADDRESS: PHONE:970.221.4158 WEBSITE: 200 S. College Ave. Suite 10 www.northerrengineering.com Fort Collins, CO 80524 FAX: 970.221.4159 Larimer County Floodplain Development Permit — Supplemental Memorandum Date: November 1, 2011 Address: 912 Wood Street This memorandum and attached exhibit are intended to supplement the application to obtain a Larimer County Floodplain Development Permit for earthwork activities within the FEMA regulatory Cache la Poudre floodplain. The subject property is located at the terminus of Wood Street approximately a quarter -mile north of the City of Fort Collins Utility Service Center. The site is owned by Sidehill Investment LLC. The land owner wishes to perform minor excavation on a portion of the property, noted as "Excavation Area" on the attached exhibit. The land owner also proposes to fill a portion of the property, noted as "Fill Area" on the attached exhibit. The proposed fill area was previously mined for gravel and the intent is to restore the ground to more closely match its historic condition. There are actually two excavation areas; both of which are located outside of the Cache la Poudre 6- inch floodway, and are within the 100-year flood fringe of the Poudre River. The first excavation will remove a berm of concrete rubble (Excavation Area 1). Said berm is not currently recognized by the floodplain modeling; therefore, there will be no change to the effective floodplain boundaries. The second excavation area will expand a small pond in the southeast corner of the property. The pond excavation is located in an ineffective flow area, and there will be no impact to the floodplain boundary or base flood elevations as a result of the proposed excavation. Please note, the "bubble area" shown for the pond expansion (Excavation Area 2) is conceptual only. The exact limits are to be determined in the field with input from the City of Fort Collins Environmental Planner. The objective is to create an organic, natural perimeter and to preserve existing trees along the shoreline. The fill area is located entirely outside of the Cache la Poudre 6-inch floodway, and is within the 100- year flood fringe of the Poudre River. The fill area is also located outside the limits of the existing septic cleanout and leach field. The fill will be placed in two phases, as shown on the Floodplain Exhibit. Phase 1 contains the majority of the fill area. The work for this phase can proceed immediately without impact to any of the existing trailer homes or access road. Phase 2 is the northwestern -most portion of the fill area. Fill in this area will not be placed until the respective structures have been removed and alternative access has been provided. Said removals and reconfigured access are expected to take place concurrent with the fill placement for Phase 1 thereby enabling Phase 2 earthwork will follow immediately after Phase 1. Therefore, it really is more of a construction sequencing issue, and not necessarily separate phases with significant gaps in construction. Both "phases" of fill placement are requested under the same permit. The proposed fill location is within a backwater area that does not convey water in the principal downstream flood flow direction. In other words, the fill will be placed in an ineffective flow area. • Proposal Review Checklist X Site development plans are complete and depict flood hazard data JJ� Engineering data is provided for proposed map and floodway revisions N/A Floodway certificate and data document no increase in flood heights N, Subdivision proposals minimize flood damage and protect utilities N/L_ Lowest floor elevations are at or above the 100 year base flood elevation !rg- Manufactured homes address elevation and anchoring requirements _{ A flood proofing certificate has been submitted Other:,t_CvW GEo-y- petrAseA 6 4jg!JJJt Iif. JnrMiF:z,.vc Permit Action and Compliance Documentation ✓ Permit Approved : The proposed project was reviewed and is in compliance with flood plain management standards as established by FEMA and Larimer County Permit Denied : The project was denied and information is in Flood Review Board files Variance Granted : A variance to the 100 year base flood elevation was granted and information is in Flood Review Board files Variance Granted : A variance was granted from the Code for all or part of the 18 inch lowest floor protection elevation Elevation Certificate : A certificate was returned before a certificate of occupancy was issued Flood Proofing Certificate : Certification was returned before a certificate of occupancy was issued ount} ood Plain Official's Signature Date sK4u. Atcrr Gaywr. �.ut 11 iL� T�L-._ AtL- fg?Mcgrs AIZAr �€ movCD ou r Q 2 _ R A-nV6 6AAE2G6nxy AtcAW AZEPtntfl.E, -M -TKE fra+009 r1aw ^JDtoai+y iS Pfzuvirx"A, P"Ar;- Mom" "17*m W uaer& aw a rAttio ,,AA is-cowh•TTeb AND A-em veo i3y (,Aavv%62 Cauuty 6#4610eWS4&4 ANO WIZM ►S Ahr a%SAT140J Ta p¢otrV)o it ♦r[ vjoelo dy vrztV.c Cauuiy rJ6 P't2T4&GfaT. E HIBIT 9 Flood Plain Development Permit Permit Number 11— FPeVS Date 3 / Owner 5iOEnu.L joyesTMCL97S ULC Phone 470-2Z?-!Mt) Address 912 Wum sTkeam Ftif e- Contractor .c Z2L., G./A,* fitsnAANA Phone 97o-u9'"W Address 37ez. A&,k-w A-M/na PNe 5,76 FO/ Project Address/Locationcflp wwa' SIXe!E� Fees ,r�L4.,vj _ Single Family Residence Multi -Family Residence Manufactured Home Commercial Project Description _ New Construction Channelization _� Fill _ Improvement >50% Bridge/Culvert _Levee _ Improvement <50% Rehabilitation _ Other Explanation: Pi6L wm+iu nic rLwofie,"g- CA -n1e "OrM RIyEIL A.3 4910t Arnrcaev /690/ Flood Hazard Data Watercourse Name 4.,ty- The project is in the Floodway �JO The project is in the Flood Fringe The 100 year base flood elevation for the project is VA E40 - 5ec AipmtecD '01-W 2.o wtv. as pciwam fat Lowest Floor Protection Elevation required add-1-5 feet FiX- Gui Psen.3�u�>inu,, tw ca,ocs Flood Proofing Elevation required N/A _ Fac Au C p►co Source Documents: Reports/Maps used 080& 9 GU9 "7 76 —FtM Fit / U P Proposed Conditions of Annexation Conformance to City Criteria' Meets Exceeds Deficient Residential development will be allowed in the LOMR-F area previously processed in the County Platted lots will be outside of the floodplain ✓ Residential structures (lowest floor & HVAQ will be elevated 2-ft above base flood levels Hydraulic modeling will be performed to assess erosion potential along floodplain boundary Land Owner willing to participate/contribute towards off -site stream bank stabilization MA 1. Realizing at this time current City code is silent on LOMR-F areas granted in the County prior to annexation. 2. This is to correct/improve a section of off -site bank that failed in April of 1999 that the City had to quickly mitigate in order to protect utility lines. It behooves multiple parties, and the general public, to ensure this section does not fail again. Simplified Comparison of County vs. City Regulations Allowed in Allowed in • County City Placement of Fill Material YES YES in 100-year Flood Fringe LOMR-F (FEMA process) to YES YES Remove Area from Floodplain Residential Homes to be Built on Filled Area YESYES Removed from Floodplain 1 S 1. New County policy requires Lowest Floor Elevation (including all HVAC, mechanical and electrical equipment) to be elevated above the Base Flood Elevation. 2. Updated City policy requires a LOMR (FEMA process) before residential development would be allowed. i 1 LJ E HIBIT � 3 Timeline of Discussions and Activities Related to Floodplain Local Authority Having Jurisdiction Date County City Met with County AND City Floodplain oct-2011 Administrators to Discuss Intentions Land Owner, Consultants, County, and City Staff oct-2011 Agreed to Process Moving Forward Nov-2011 Obtained a Flood Plain Development Permit Placed Fill Material in Flood Fringe Nov/Dec-2011 (while performing other site clean-up) Had Fill Material Tested by a Nov/Dec-2011 Geotechnical Engineer Dec-2011/ Had Fill Area Surveyed by a Jan-2012 Licensed Professional Land Surveyor Jan-2012/ Applied for, and Obtained, a LOMR-F Mar-2012 from FEMA Removing Area from Floodplain Apr-2012 Submitted Petition for Annexation °i ZONE AE f� FLOODING EFFECTS FROM ZONE X -4982-4983 CACHE LA POUDRE RIVER ZONE X h � mrn, rn 4966' 4964 a AFRMAN f. DIRT ZONE C zoNe x' ZONE (SaIf" to tbadre Niter ZONE X ZONE A x I ZONE X ro 2 pa � 2008 ZONE — x a U ZONE x 2011 LOMR-F Fill Area M r N ZONE X Cache La Arthur Irrigation Dltch Vwr DRIVE 4 PouAre River U CITY OF FORT COLLINS B`"�Tol 080102 z ''Jt SAT 1460000 FT 9'9N,gq FUI S T ... '�'44fo '� •� C1M 37\Er CITY OF FORT COLLINS 080102 )NE X ZONE x LaM Cam gveFaron GUFn ZONE AE ZONE X -um— MAP SCALE 1"=600' 0 5D0 10016T METER 0 150 3D0 PANEL 0977G FIRM e FLOOO INSURANCE RATE MAP p LARIMER COUNTY, C COLORADO tell. AND INCORPORATED AREAS PANEL 977 OF U20 a (SEE NM NAE% FM FAM PM'EL LAYWII S,!]!5[!11 mN6EN Z1SLl 91Ffn mr wen e,.e my a Ak'W: AWN �u�- 0 O vt AA�,.� Vn C .�j ••mn• MAP NUMBER / ORNSCOTIG 010y7 �C—, 4 MAP REVISED JUNE 17, 2008 Fr4rnl I:mm6mrr M.n. frmew.\ fene7 � "LL0476 U -- ZONE X JOINS PANEL 0979 cacheLa -r m.n F .,nmma m..a r+.en o.•+.» m. m.P m...m,.«�eA.••am 105 V317.ao' wwiroue SHFMN)OD omm 93 E Poudrc .m.,m...,,m..mm,.,.e.�..m...•....e+mLromr.am. E.e a:< Fm Pro urn, mrm.,immm.ns,sm. wmmnaw.mvmre STREET sET Onarvmn .m.eoa m.p.n.<Y nn FEMA Fbm Mw aer..l w.wn•.e F.•.pv. 1996 with 1986 Overlaid at the Project Area and LOMAR-F Fill Area ZONE A7 J J � f6MAV PIT OMIT OF b ^ OEIAIL U G STUDY b n ZONE A b 9Ej b .non Ames Ofth UM U m� c> oy NOF>yA,Ni' L^7 APPROMMAt1 SLAU IN I L _ii IANF Al ZONE Al (UNION PACIFIC WESTVIOOn OPrvF ZONE A I rnmxn noel milli, fn 6 rxn FIRM ZONE A7 \ FLOOD IXSOAANAP 2 LARISIER �n COLORAO Ati'i i - --- Clly OE Fort Collin➢UNnNCORPI1kA AREAmor INCLUOEO I P1NEl I F271 ORERMAN •• ar r.m m n CO11PT ZONE ^ A7 _ loom � t seo gt o Ids IyRANE1 chat 0118one D .se Ab MAP REyEsm: l' MARCH 19. 1916 !! l.:IniliirFl R —__ y^^ 1986 Y m[rlamY M.uPmnl Almey 19j1 \I ZONE A7 1996 'cL ""' \ LOMR-F Fill Area 2011 w.m mp �. e.ro a�.b o.aa ro m. a.la m, ua aVR1YMIP�atlPnnM4]P M.N 4RtlIRMMJ Y.VYK I.m.P. <M[Y tN. FE4I. F6m Mro £u..I xvw.me Yn.• 1996 with 1986 Overlaid at the Project Area L\4 NPPKoX1M,1tE 1LAIA IN 1 t G00 0 1 V,111K IANF 4.9V � 11 — ZONE Al ONE A7 GRAVEL P17 9 UNION eIEIDOF s WEeTW00D MWE FLOODING EFFECTS CREEK FROM RY ► ZONE A _ ARIIARRL IUOE NEr1 f TEPEE ► a I LNAR/ ^ DSTVDY FIRM ► = e III FLOOD INSURAN@%%pI ►� ZONE A7 ZONE A y _ r. LARIMER COLORAD ►A p C4CyA' ON of Fort Collim AREA NOT INCLUDED rUNINCORPORA ABI ,MFh Ames unFn UA+rs.On W 99A� �' 'I PANEII 9 � - [ICERAMR cwERT ZONE I CIO, 71 ro r A8 o `"� C TY PANEL NUMBER 'ii ,L D8010101 is 40Bi H tar�,tEnr:r Im MAP REVISED: MARCH 1N9A . 19 y. 1986 3 i;' mEemyMgemm.A/My 6912 -- ZONE A7 IFL A"I' it ILA, 1996 11 � wnanbnc/b whF. mi. N'n Ocv� n�Rtl .r40Wr�. b My 4i. an IM I.Yf q%n �W IM I.IXI po0.RHrYp`NOYI MM1I YAr1Ae Hitl IAVYeO IT 1n�EMA myl cHtk tlu FEMAfW My Etu..IwM. mF[M+'• A7 a »a P a - LIMRGF y DETAILED STUDY a �ayv ZONEA7 ti ZONE A a as - 9 a cACH� �0 � ,IoiA A., Dh DiwntM Dim b a3 a99A a �'o a ro .. APPRU%IMATL SCALL IN I C \ZONE Al UN10N PACIFIC\ WESTWODD DmvE ZONE - ---- - I1410M FEW MAP Imul FIRM ly FLOOD INSUAA111194WAP lli.''.I LARIMER CDLDRAD RDr ns Colli ! toRINCDEPDRA SI - - PX NOT IN INCLUXED AE �(� ACKEXMAN _ PANELI f77A � COURT ZONE A7 I' ; ggp RlV o i j�'' .� TY1PANEE NIIYIEII pglSl NUNWE egg �ru1 j�� MAP REVISED. MARCH IS. 1996 lvclncr.L IvgA Rli'LR \\JJ F� �r n g Eq]3 Project Area ZONE A7 .. IEL 49] I I 1986 T 0 1 q ).iAwfer? - .gFjf-6'E6 - GI, A APPROXIMATE f ,j ^, _ -_- 1 b� PRORIM SCALE IN FLET — --ZONES ZONEA1 [ III Pq I NATIONAL P1000 INSURANCE PROGRAM1 -- �, 1 ° ZONE AQ FIRM FLOOD INSURANCE RATE MAP ,q City or Fort CnRin: LARIMER COUNTY, AREA NOT INCLUOEO CO OR DO \' (UNINCORPORATED AREAS) PANEL 178 OF 278 ISLE MAP INDEX PORPANELS NOT.A NTF.I IX 40. --- (-1"rl7 nr b q1 " q COMMUNITY PANEL NUMBER x Mn1� 080101 0178 C \ I MAP REVISED: MARCH 18, 1986 I Project Area � L�,&�l lgency Alanpgemenl Agency � 1M n Yr Pf4Y [eq d 1 mrlrm W W �W� r[Ynmm 11aoC m�P Y u[up G.Mi On{irc Tx[mNa fIpllMMmlercnpF[ wnMnenY M[[E rruY YM ONrI mM [ WiYpMn le Irc CIa m ms I m�tlmY Fm1rc Nw11/mWYtlib'mYm IN1 NYeN FimClrcwee� Prrgnm ImE mNs [Mck Ire FEMR Flmf My 61wc N vwx mw k+na � E HIBIT . 1 1 1 i 11 r? .l ♦ • ' t.A � r•+gr� I `t • 1 ti. R • R V' ' it ' � I . .�►� �� 1 • • _ ' \'.a + `W+ �� )�J T 00* S ^ a 'iQ.. •� r .�. < � ` < �• IN AL._ • v ,t I d :�•• . R e 144 w < y fl:• �' in for. a ram. -`M�•r. ytr�+.�l.�.awr.. a.. Ita p`, ', •lam NO . w T 0-00•• fR ` 006 SA Imp •'� .s ,!" • i [ To I �r I � •' �• �, ' 1{ 'din• 11 �f i Igor r li 01, ��Vlne Drive f 11-Year Flood 1rJ Fringe A tell Ir r Orr L'ut h yy d►.. -� ---ter=. �1f riFITMMMO••• .. �` !+ West Vine Drive A A Year Flood 100- i • . 1kI • 1 ,.!s �� •'? /Mfg t,� ii)�' s 1 i �' Aw. IN ON Me 02 =so slIZOMM IWI It jr .r+ i � - arle � � ` b • r • II s •"9 - R 'tow. M ir 1• AT 1 .er.. ti y Pon /4ow.ALI ilia, •_,,; y K 3 IT? r r mow..* .