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HomeMy WebLinkAboutResolution 841 - Approving Floodplain Dev. Permit for Twin Creeks RR X-ing improvementsRESOLUTION NO. 841 A RESOLUTION OF THE PLANNING COMMISSION APPROVING A FLOODPLAIN DEVELOPMENT PERMIT/NO-RISE CERTIFICATE FOR CONSTRUCTION OF TWIN CREEKS RAILROAD CROSSING ROADWAY IMPROVEMENTS WITHIN THE GRIFFIN CREEK FLOODWAY (File No: FP 16002) WHEREAS, the applicant has submitted a Floodplain Development application and No -Rise Certification to construct roadway improvements, including pavement reconstruction, and curb and gutter and sidewalk construction in the Griffin Creek regulatory floodway on a portion of Highway 99 in Central Point, OR 97502. WHEREAS, the No -Rise Certification was prepared in accordance with FEMA's Guidance for "No- Rise/No-Impact" Certification for Proposed Developments in Regulatory Floodways; and WHEREAS, the No -Rise Certification confirms that the proposed roadway improvements will not increase the base flood elevation or floodway profiles relative to the effective FEMA mapping; and WHEREAS, on February 7, 2017, at a duly noticed public hearing, the City of Central Point Planning Cornmrission considered the Applicant's request for floodplain development approval for the Twin Creeks Railroad Crossing Floodplain Development Permit/No Rise Certification (the "Project"); and, NOW, THEREFORE, BE IT RESOLVED that the City of Central Point Planning Commission by Resolution No. 841 hereby approves the Twin Creeks Railroad Crossing Floodplain Development Permit/No-Rise Certification based on the Staff Report dated February 7, 2017, including attachments incorporated by reference (Eklnbit "A"); and PASSED by the Planning Commission and signed by Vminaulthen'ration of its passage this 7h day of February 7, 2017 mission Chair A ST: ,( u� 5i-�- %, CitARepresentative Planning Commission Resolution No. 841 (2/7/2017) City of Central Point, Oregon 140 S 3rd Street, Central Point, OR 97502 541.664.3321 Fax 541.664.6384 www.centralROintoregon.gov Xcoa CENTRAL POINT Oregon STAFF REPORT February 7, 2017 AGENDA ITEM: File No. FP -16002 Community Development Tom Humphrey, AICP Community Development Director Consideration of a floodplain development application to construct Highway 99 roadway improvements within the Special Flood Hazard Area (SFHA) and regulatory floodway for Griffin Creek. Applicant: City of Central Point (Matt Samitore). STAFF SOURCE: Stephanie Holtey, CFM, Community Planner II BACKGROUND The City of Central Point ("Applicant") requests floodplain development approval to construct roadway improvements within the Special Flood Hazard Area (SFHA) and regulatory floodway for Griffin Creek (Attachment "A"). The proposed improvements are needed to complete construction of the Twin Creeks Railroad Crossing project, which is identified in the Twin Creeks Transit Oriented Development (TOD) Master Plan ("Master Plan") and the City's Capital Improvement Program (CIP)(Project No. 202) as a vital link between Twin Creeks and development east of the CORP railroad. To be approved, the Applicant must demonstrate that the proposed improvements do not aggravate flood conditions. Project Description: The Twin Creeks Rail Crossing project will extend Twin Creeks Crossing easterly across the CORP railroad tracks to create a new, signalized "T" intersection with Highway 99. Additional project improvements include the following: • A new at -grade railroad crossing; • Sidewalk, curb and gutter construction along the east side of Highway 99 to the north and south of the new intersection; and, • Pavement reconstruction raising the grade along Highway 99 to match the grade elevation at the intersection. A portion of the pavement reconstruction and sidewalk improvements, including curb and gutter, are within the Griffin Creek SFHA and regulatory floodway. In accordance with CPMC 8.24.200(A), the Applicant submitted a No -Rise Analysis and certification, which evaluates the effective and proposed flood conditions based on construction of the Twin Creeks Railroad Crossing project. According to the No -Rise documentation, the minor grade increases do not increase flood elevations consistent with the City's no -rise standard. ISSUES There are no issues associated with this application. FINDINGS OF FACT AND CONCLUSIONS OF LAW The proposed floodplain development has been evaluated against the Central Point Municipal Code (CPMC) Chapter 8.24 requirements for Flood Damage Prevention and found to comply as evidenced by the Applicant's No -Rise documentation (Attachment `B"). CONDITIONS OF APPROVAL No conditions of approval are recommended. ATTACHMENTS Attachment "A" — Floodway Development Project Location Map Attachment `B" — No Rise Certificate and Analysis (Note: Appendices are included in the record and available for review upon request) Attachment "C" — Floodplain Development Application, dated December 14, 2016 Attachment "D" — Resolution No. 841 ACTION Consider the floodplain development application and 1) approve; 2) approve with modifications; or 3) deny the application. RECOMMENDATION Approve Resolution No. 841 Approving a floodplain development application to construct Twin Creeks Railroad Crossing improvements within the regulatory floodway for Griffin Creek. NOTE MAP AREA SHOWN ON THISPANEL IS LOCATED WITHIN TOWNSHIP 36 SOUTH. RANGE 2 WEST AND TOWNSHIP 1MnTd S1LOr 37 SOUTH RANGE WEST ,'e3 --N 3n •fl } +23� E F� i 2!0 1 I G J . ATTACHMENT "A" Twin Creeks Railroad Crossing Project Location & Flood Map N n 4 &-� [I tai rwn ae.w: aoumy '11—N City of — Central Point 410092 Profile emllne , Jackson County Unincorporated Are" 415589 r..A.m,.,,i'. �� iarV►! �+r.�r ZONE AE AYW>a ` .• IP33.3 f •H V. r "--'ZONE AH 1120.01 ;H PTeSlle ti Bas@llnN ` 12 a n!rNI 4. Approx limits of ,��, _HCIN/114 1 '. N % Pavement fi GilNCrtleE r=� •p1 reconstruction �% 5737 ' 11 4 Extended i flowaII, ? aM1 curb and gutter -" 1267 �rs 11{f Jackson County pincurporatWAreas REFLECT LOMR • EVISEiJ �.�. --� September14, 2016 � h 4�J ,�Z ►' *, AREA w„ 1 l.i " 1' a< 415589 233 ri+4�+1 iart Jackson County. $ .k r..A.m,.,,i'. aawcer wA. �� iarV►! �+r.�r Ik .00(� f SCALE r "--'ZONE AH 1120.01 ;H PTeSlle ti Bas@llnN ` 12 a iiilll I .rr-�ti1 rwv 4. Approx limits of ' % Pavement fi GilNCrtleE r=� •p1 reconstruction V Floodplain res s �^� ' 7255.0 11 4 Extended i flowaII, ? aM1 curb and gutter -" 1267 �rs aawcer wA. �� iarV►! �+r.�r SCALE r prdis Baseline iiilll I .rr-�ti1 rwv •r[ 0.4P,NlCE �XK006�ic4YK1.A0AIIM ![�WanCpn41 —176 l r fi GilNCrtleE r=� •p1 Affected '0 . Floodplain res s �^� ' 7255.0 R �} .151 VIM, REVISED TO REFLECT LOMR ,a EFFECTIVE; �.�. --� September14, 2016 � h 4�J •ra+pl4 r rre 7YUNIN I i_RNAI IONIA. I ATTACHMENT "B" Twin Creeks Rail Crossing Floodway Impact Hydraulic Step Analysis September 2016 Revision 1 Prepared for: City of Central Point c/o ODOT Region 3 Prepared and Submitted by: IYLIN INTERNATIONAL -TY0NIN I ERNAI ZONAL Purpose and Need The City of Central point wishes to extend the Twin Creek Crossing form its current terminus west of the CORP railroad tracks to a T intersection with the Rogue Valley Highway (HWY 063). The project requires the grade of Hwy 063 be raised to match elevation at the intersection location, and will develop sidewalk along the east side of the highway in both directions to connect with approaching sidewalk termini. The project re -constructs a portion of the highway over the twin box culvert passing Griffin Creek. Per the FEMA flood insurance map this development will be within the floodway where Griffin Creek overtops this culvert in the 1% probability (100year) flood event. 1246.0) '+- "IM, Profile 'f Baseline/ 'k `, F Baseline I ,iw.1lpORl11 JAM _LQp * i25� 1',% ANNUAL -CHANCE `FLMD DISCHARGE CONTAINGO o ew.s rz: 1�5 zn Approx limits of Pavement M1* INSTRUCTURE ti e Nu7oN+AROOM wswuNrF.wacs,AM — JACKSON COUNTY(RIEGON reconstruction gnaw 1768„2327 ►/r Affected !i 1257.4 �f ' Floodplain area � °"°^" 1�0 Extended sidewalk 1255.0 curb and gutter _.+�= V N ISTSTNEET 1257.r .5S3w1 REVISED TO " 12611 REFLECT LOMR 1259.9 ,6. G} c p4, s EFFECTIVE; g1 } ,�'•I>.IH,s 1K y' U a September 14, 2016 nrrN y • nn^ aa��' J YrW17G9F W d1029/:1766F 1243.4 - Ionr=. NAY 0, 2011 Floodplain Area Affected Hwy 063 Griffin Creek Culvert Analysis Procedures The location under consideration is currently in public comment for map revision to capture modifications to the intersecting Jackson Creek drainage west of the CORP Railroad alignment. At flood stage Griffin creek overtops the bank to the north and flow is diverted northerly to the Jackson Creek basin. The proximity of this flow modification to the project site, illustrated above, leads to the step backwater analysis performed for that revision as the most current model capturing these already constructed modifications within the drainage system. Therefore, the current published insurance study, Number Twin Creeks Rail Crossing Project N a a L ) 1 Floodplain Impact Analysis (June 29, 2016) TYUNIN rERN.ADONAL 41029V000A effective May 3, 2011, is outdated, and the pending study analysis, to be fully effective September 2016 has been used as the basis for this no rise comparison. The comparison analysis for this no effect documentation was acquired directly from the consultant performing the Letter of Map Revision (LOMR), which fully re -modeled the drainage basin including Griffin Creek. Therefore the cross sections compared do not exactly align with the 2011 effective insurance study, and therefore no annotation of the tabular values in that study can be provided. Fortunately, the work in question is centered about the culvert feature which provides cross sections at that location and can be aligned with all previous flood studies providing a basis of comparison and has established confidence in the existing conditions analysis. The procedure uses the LOMR HEC RAS steady flow step backwater analysis model, expected to be effective September 2016 and as developed originally by Northwest Hydraulics Consultants under contract to the City of Central Point. No new cross section locations were developed for the proposed conditions analysis, hence no calibration of the existing conditions is needed. All modifications have been to the deck elevations to the existing culvert section modelled at River Sta 58+84. The culvert upstream and downstream deck elevations were modified to reflect the proposed road profile above the culvert location and compare to the previous existing condition. vi II;�M Oe�rwn ryw�! Griffin Creek Culvert Existing Road Surface Twin Creeks Rail Crossing Project _. P age 12 Floodplain Impact Analysis (June 29, 2016) iYLININ ! 1 _i1NAHMIA( a Griffin Creek Culvert Proposed Road surface Notably minimal changes in roadway elevation occur, the primary modification to the proposed surface is the inclusion of drainage curb along both side of the highway. To complete the no rise the curb line required lowering from typical design height within the limits of the culvert passing below. The modifications to the culvert section were prepared using the Bentley InRoads design package to model the location of the roadway gutter line. The gutter line establishes the parallel elevation and the various features of the new roadway are installed to re -define the roadway surface for the proposed conditions model. Specifically the upstream culvert roadway was modified to capture drainage curb along the west edge of the roadway to the anticipated limits of the project. The existing points in the cross section were measured and modified to reflect the higher elevation. Downstream culvert roadway surface was similarly modified but extended to the limits of the cross section to reflect the full length installation of new sidewalk curb - ----- td -gutter along the east -side of the highway, In that case-th"levations-recorded are the-greatest-ofthe back of sidewalk (gutter line + 8 inches) or the centerline of the roadway crown. The location to the limits of the culvert required lowering of the sidewalk, similar to a driveway curb -cut, to prevent any calculated rise at the sections examined. Additional cross section points at the road surface were added to both upstream and downstream sections to capture abrupt changes, for the curb along the west side of the highway (upstream) and for the concrete barrier at the culvert along the east side of the highway (downstream). Upon completion of these modifications HEC -RAS software was executed and the resultant predicted water surface elevation differences compared at the local cross sections. Results and Conclusions Comparison of local cross sections: Twin Creeks Rail CroainpProiect P a g e € 3 Floodplain Impact Analysis (June 29, 2016) TYLININfFRf UV 4 )Mid, X -Section Station 5955.071 5884 Culvert U 5884 Culvert D 5807.13 LOMR analysis i Water Surface 100 yr. 1256.4 1256.4 1255.6 1255.0 Proposed Surface Water Surface 100 yr. 1256.4 1256.4 1255.6 1254.9 100 yr. Difference 0.0 0.0 0.0 0.1 The analysis shows no rise for these four stations. Notably the rise at River Sta 58+07.13, just downstream of the culvert is -0.1 feet reflecting a slightly increased flow velocity of the overtopping flow at the downstream culvert end. The final conclusion is that with the proposed sidewalk curb -cut geometry there is no calculated rise within the vicintiy of the roadway modifications. Disclaimer The analysis prepared has relied on information in support of the current LOMR being considered by FEMA to become effective September 2016. Notably at this time it is our understanding that FEMA has accepted the modeling and the LOMR application is currently undergoing the required public review and comment period. While every effort has been expended to verify that this model is consistent with the results as illustrated in the currently effective insurance study, should this LOMR not be placed into effect as scheduled and the modelling subsequently changed it may affect the input into this analysis. With that understanding the goal of this analysis is to verify no rise to the floodway and demonstrate acceptable localized rise for the 1_00 year flood water surface due to the planned roadway develo meet, aind regardless of any modification to the supporting analysis it is reasonable to conclude that the specific results for this location will remain unchanged. Twin Creeks Rail Crossing Proieet_ Floodplain Impact Analysis (June 29, 2016) Page 14 Date fir :a ves1.. m Floodplain Deveiopment Permit No.� City of Central Point Floodway Encroachment Analysis CENTRAL No -Rise Certification POINT PROPERTY INFORMATION PROPERTY OWNER'S NAME City of Central Point PROPERTY ADDRESS (Including Apt, Unit Suite, and/or Mg. No.) OR P.O. BOX NUMBER 140 South 3rd Street CITY STATE ZIPCOOE Central Point Oregon 97502 PROPERTY DESCRIPTION (rAw and TaSlot Numherl BUILDING USE (e.g. Residential, Non•re0deatlei, Detached Garage, Addition, Accessory, etc,) 37 2W 03DB No tax lot Highway FLOODWAY ENCROACHMENT ANALYSIS AND NO -RISE INFORMATION PROJECT/ENCROACHMENT DESCRIPTION (Please be specific. Attach site plan andinclude additional pages If necessary) Raise of grade to accommodate intersection at Twin Creeks Crossing and highway 99 results In some adjustment to highway grade through the Griffin Creek Hoodway. Structural encroachment es ANO T~ Fill placement qfYes 1 No Quantity: 12& Brox, _____..:cubic yards Material Type: Various - Goncrete AACWS and bas_ a aggregate Material Source: Commercial supplier TSD FIRM COMMUNITY -PANEL NO. EFFECTIVE/REVISED DATE BASE ROM ELEVATION (NAVA 14x8) SUPPORTING TECHNICAL DOCUMENTATION 1 Report with analysis 2. 3. COMMENTS: Analysis prepared from current LOMB model effective September 2016 to capture the most current effects at this location. OREGON REGISTERED PROFESSIONAL ENGINEER CERTIFICATION I certify that I am a duly registered professional engineer licensed to practice in the 5tate of Oregon. I certify that the attached technical data supports the fact that the proposed development described herein will not Impact the 100 -year (1% annual cha rice) flood elevations, floodway elevations or floodway widths on the affected stream located both upstream and downstream of the proposed development, at published or unpublished crossections in the FEMA Flood Insurance Study specified in Section a of this No -Rise Certification. Scott M. Nettleton P.E. CERTIFIER'S NAME TY Lin International COMPANY NAME 862$!% Cascade Ave Suite 604 Beaverton OR 97008 ADORE CITY 51'ArE 2IPCO10E r LL IsT RE DATE Expires 12/31/2016 140 South 3rd Street I Central Point, OR 97502 1 (541) 664-7602 www.centralpointoregon.gov Alk Floodplain Development Permit CENTRAL Application POINT ATTACHMENT "C" OFFICE USE ONLY EC No -Rise 'CLOMR Attochments Approved .Denied Subject to COA Instructions: Complete all unhighliehted sections of this application form to provide a complete understanding of your development proposal. Highlighted sections are for office use only. Please incude attachments to help clarify your proposal. These may include a site plan, elevation drawings, detailed drawings and photographs. Refer to the application checklist for a complete list of required supporting documentation. Incomplete applications will not be accepted. Contact the Floodplain Coordinator at 541.664.7602, Ext. 244 if you have any questions. SITE ADDRESS: Map and Taxiot A: 37S 21117 03 -DB Highway 99 at Twin Creeks Crossing FIRM Map& Ponel No.: a1O29C Flood Zone: Jx Floodway BFE: 1255.0-t256.4ft. NAVD88 Base Depth: NPA jt, I Minimum OFF: OWNER NAME: City of Central Point (Matt Samitore) APPLICANT/AGENT NAME: N/A MAILING ADDRESS: 140 South Third Street, CP 97502 MAILING ADDRESS: PHONE: I E-MAIL: PHONE: E-MAIL: 541.664.7602 Matt. Sam itore0centraloointoreaon.aov As part of the Twin Creeks Rail Crossing project (construct new intersection), highway grades must be raised to match the elevation at the new intersection and new sidewalks constructed. The highway grade adjustments and sidewalks will occur within the SFHA and regulatory floodway. A No -Rise Analysis has been prepared and demonstrates no adverse impact. Type of Use (Check one): Residential Mixed Use (residential and non- residential) Non-residential (commercial, accessory) -' Elevated 11 Floodproofed (attach certification) i_7 Manufactured Home F Located on individual lot Located in manufactured home park Type of Activity (Check one): New structure Replacement of existing structure Relocation of existing structure' Addition to existing structure Remodel to existing structure Additions & Remodel Information: 1. Year Built: 2. Existing Bldg. Valuation: $ Source: 3. Proposed Const. Cost: Source: ' Relocated structures are treated as new construction ' Additions and remodels that exceed 501Y of the market 4(a). Addition Type: value of the existing structure are a substantial _'. Vertical improvement, which requires full compliance with Ch. 8.24. J Lateral Improvements are counted cumulatively over a 10 -year 4(b). If Lateral Addition, is it structurally period. connected? a Yes No 1. Lowest habitable floor elevation: 3. Area of enclosed area below the BFE: Other Structural Project Information: feet, NAVD 88 2. Garage Slab Elevation: feet, NAVD 88 sq ft. 4. No, proposed flood openings: Total Area: so ft Check all the proposed non-structural development activities associated with your project, as provided below. 7 Tree, vegetation and/or debris removal i_ Bridge or culvert replacement Excavation qt (cu yards): _; Stream bank stabilization KS Fill placement I City (cu. yards): —125 _ Watercourse alteration Grading (attach project grading plan) _ Subdivision with improvements in the SFHA Fence or wall construction Capital Imrovement Project (Functionally dependent use V.1 Swimming pool installation Other: By signing below, I agree to the terms and conditions of this permit and certify to the best of my knowledge the information contained in this application is complete, true and accurate. Matt Samitore 12-14-2016 (PRINTED name) (SIGNED name) (pate) ffIRIN7F.17 name) Updated 1/13/2012 (SIGNED name) (Date) ATTACHMENT "D" RESOLUTION NO. 841 A RESOLUTION OF THE PLANNING COMMISSION APPROVING A FLOODPLAIN DEVELOPMENT PERMIT/NO-RISE CERTIFICATE FOR CONSTRUCTION OF TWIN CREEKS RAILROAD CROSSING ROADWAY IMPROVEMENTS WITHIN THE GRIFFIN CREEK FLOODWAY (File No: FP 16002) WHEREAS, the applicant has submitted a Floodplain Development application and No -Rise Certification to construct roadway improvements, including pavement reconstruction, and curb and gutter and sidewalk construction in the Griffin Creek regulatory floodway on a portion of Highway 99 in Central Point, OR 97502. WHEREAS, the No -Rise Certification was prepared in accordance with FEMA's Guidance for "No- Rise/No-Impact" Certification for Proposed Developments in Regulatory Floodways; and WHEREAS, the No -Rise Certification confirms that the proposed roadway improvements will not increase the base flood elevation or floodway profiles relative to the effective FEMA mapping; and WHEREAS, on February 7, 2017, at a duly noticed public hearing, the City of Central Point Planning Commission considered the Applicant's request for floodplain development approval for the Twin Creeks Railroad Crossing Floodplain Development Permit/No Rise Certification (the "Project"); and, NOW, THEREFORE, BE IT RESOLVED that the City of Central Point Planning Commission by Resolution No. 841 hereby approves the Twin Creeks Railroad Crossing Floodplain Development Permit/No-Rise Certification based on the Staff Report dated February 7, 2017, including attachments incorporated by reference (Exhibit "A"); and PASSED by the Planning Commission and signed by me in authentication of its passage this 7`11 day of February 7, 2017 Planning Commission Chair ATTEST: City Representative Planning Commission Resolution No. 841 (2/7/2017)