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Resolution 806 - Twin Creeks floodway dev. permit for mitigation project
• RESOLUTION NO. 806 A RESOLUTION OF THE PLANNING COMMISSION APPROVING A FLOODPLAIN DEVELOPMENT PERMIT FOR THE TWIN CREEKS FLOODWAY MITIGATION PROJECT (File No: FP 14001) WHEREAS, the applicant has submitted a floodplain development application to conduct grading and channel protection activities on property identified on the Jackson County Assessor's map as 37 2W 03CA, Tax Lots 900 and 1600; 37 2W 03DB Tax Lot 900; 27 2W 03BD Tax Lot 4200; 37 2W 03BC Tax Lot 100; 37 2W 03B, Tax Lots 1602 and 1800 in Central Point, OR 97502. WHEREAS, the project site is located in the TOD-OS, Open Space zoning district; and WHEREAS, the application has been found to be consistent with the applicable approval criteria set forth in Chapter 8.24, flood damage prevention standards for floodway development and per conditions noted in the Staff Report dated August 5, 2014; and WHEREAS, on August 5, 2014, at a duly noticed public hearing, the City of Central Point Planning Commission considered the Applicant's request for floodplain development approval for Twin Creeks Floodway Mitigation Project (the"Project"); and, NOW, THEREFORE, BE IT RESOLVED that the City of Central Point Planning Commission by Resolution No. 806 hereby approves the Twin Creeks Floodway Mitigation Project based on the findings and conditions of approval as set forth in Exhibit "A" the Revised Staff Report dated August 5, 2014, including attachments incorporated by reference; and BE IT FURTHER RESOLVED that the Planning Commission hereby modifies Condition No. 2 of the Staff Report dated July 1, 2014 for North Village Phases I, II, and-I-I!Tentative Plan (File No.,Ff 140(4) to allow grading within the Project's floodplain in accordance with Condition No. 2 of the Staff Report dated August 5, 2014 (File No. FP 14001). PASSED by the Planning Commission and signed by me in authentication of its passage this 5th day of August, 2014 7 Planning Commission Chair A E'• ' City 'e'resentative Planning Commission Resolution No. 806 (08/05/14) City of Central Point, Oregon CENTRAL Comm 140 S 3rd Street, Central Point, OR 97502 Unity Development Fax 541.664.6384 POINT Tom Humphrey,AICP pment www.centralpoinrego � Community Development Director REVISED STAFF REPORT August 5, 2014 AGENDA ITEM: File No FP 14001 Consideration of a Floodplain Development application to complete floodway including both in-channel bank protection for Griffin Creek, and upland grading activities. The is located in the Twin Creeks Master Plan area, OS, Open Space mitigation activities the Jackson County Assessor's map as 37 2W 03CA, Tax Lots 900 and 1600. 37 p e zoning district and is identified on hx project 27 2W 03BD Tax Lot 4200; 37 2W 03BC Tax Lot 100; 37 2W 03B, Tax Lots 1602 dDl 00 Tax Central Lot 900; Point, OR 97502. Applicant: Twin Creeks Development Co.,LLC; Agent: Dan O'Connor. or. STAFF SOURCE: Stephanie Holtey,Community Planner II BACKGROUND: When originally approved the Twin Creeks TOD was not subject to special flood hazards and Chapter 8.24, Flood Damage Prevention requirements. With the adoption of the new FEMA Flood Insurance Rate Map in 2011 a substantial percentage of Twin Creeks was placed in the special flood hazard area, including 68 lots in the floodway(Attachment "C ' nc Creeks requires mitigation to eliminate floodway impacts on commercial and residential 1 twin s. time the applicant has prepared engineered plans (Attachment "B")and submitted a floodplain this development application to reduce flood hazards within the Twin Creeks Master Plan area. This project proposes to mitigate floodway impacts that currently limit development potential. The mitigation of floodway impacts not only requires a Floodplain Development Application, but it also includes approval of the following agencies: • FEMA to conditionally modify the Flood Insurance Rate Map (Attachment "A"); • Army Corps of Engineers to conduct fill and removal activities; and, • National Marine Fisheries to verify Endangered Species Act compliance. The proposal includes construction and grading activities to efficiently convey floodwaters from Griffin Creek northward through an existing channel parallel to the railroad tracks and direct flow westward into Jackson Creek(Attachment "B"). Construction activities proposed include: • Protecting Griffin Creek channel from erosion; • Expanding the existing stormwater ponds located south and north of the existing bioswale; and, • Grading to widen the existing bioswale channel from 30 to 75 feet. The applicant's analysis of the project impacts provided in Attachment"A"demonstrates that floodway impacts to commercial and residential lots will be eliminated and floodplain boundaries and floodwater depths will be reduced. Page 1 of'3 The proposed floodplain development application has been evaluated against the applicable review criteria as presented in the Planning Department Findings(Attachment "D"). ISSUES: 1. FEMA Review& Construction Timing. FEMA review and approval is mandatory(CPMC 8.24.170). At this time the FEMA application has been prepared and pending submittal. The City's approval of a Floodplain Development Application is conditional,pending FEMA approval. The pending review by FEMA will confirm that the proposed mitigation activities will result in the flood map changes shown in the application,including: • Removal of all residential and commercial lots from the regulatory floodway; • Reduction of the floodplain boundaries and flood depths; During the review process,FEMA may require changes to, or conditions on the project and/or the hydraulic models. To address the potential for project changes, staff is recommending conditional approval of the Floodplain Development Application subject to written approval by FEMA in the form of a Conditional Letter of Map Revision(CLOMR) approving the project as provided in Attachment "A". 2. The Applicant has requested that grading within the floodplain be permitted prior to issuance of a CLOMR. Chapter 8.24,Flood Damage Prevention does not prohibit grading within the floodplain. However, any grading within the area of the Floodplain Development Application needs to be consistent with the FEMA's CLOMR,which has not been submitted. The Applicant has agreed to accept all responsibility and outcomes relative to grading within the floodplain, coordination with FEMA throughout the CLOMR review, and ultimate issuance of a LOMR. CONDITIONS OF APPROVAL: 1. Prior to the start of construction (grading within floodplain), the applicant shall submit to the City: a. Proof of submittal of CLOMR to FEMA; and b. A copy of all local, state and federal agency permit approvals. Project timing and habitat monitoring requirements set forth in agency approvals shall be a condition of this Floodplain Development Application. 2. Prior to start of construction (grading& channel protection within the floodway), the applicant shall submit to the City: a. A copy of the CLOMR from FEMA. b. A copy of all local, state and federal agency permit approvals. Project timing and habitat monitoring requirements set forth in agency approvals shall be a condition of this Floodplain Development Application. ATTACHMENTS: Attachment"A"—Twin Creeks CLOMR Submittal Application Attachment`B"—Twin Creeks Floodway Mitigation Engineered Plans Attachment"C"—Effective&Proposed Flood Conditions Attachment"D"—Planning Department Supplemental Findings of Fact(Available upon request.) Attachment"E"—Resolution No. 806 Page 2 of 3 ACTION: Consideration of Resolution No. 806, Floodplain Development Application for Twin Creeks Floodway Mitigation with Conditions of Approval. RECOMMENDATION: Approve Resolution No. 806,Floodplain Development Application for Twin Creeks Floodway Mitigation with Conditions of Approval. y Page 3 of 3 ATTACHMENT `Ef� Memorandum Northwest Hydraulic Consultants 16300 Christensen Road,Suite 350 Seattle, WA 98188 206.241.6000 206.439.2420 (fax) DATE: July 28, 2014 TO: Bret Moore NHC PROJECT:200044 COMPANY/AGENCY: Twin Creeks Development Company, LLC FROM: Peter Brooks, P.E. SUBJECT: FEMA Conditional Letter of Map Revision Application for the Twin Creeks Development Project Introduction Northwest Hydraulic Consultants Inc. (NHC) has been retained by the Twin Creeks Development Company LLC(TCDC)to prepare a Conditional Letter of Map Revision(CLOMR) application package for the Twin Creeks Development in the City of Central Point(City),Jackson County,Oregon (FEMA Community Number 410092). The Twin Creeks Development is located along a recently designated FEMA 100-year floodplain (Zone AE), with regulatory floodway, which became effective with the adoption of the Jackson County Flood Insurance Study(FIS) in May,2011(FEMA,2011). The floodplain overbank of Griffin Creek to the the development is an overflow path that connects the left ri ht overbank of Jackson Creek. right conceptual-level flood improvement design has been developed to more efficiently convey Griffin Creek overflow through the site. The primary improvement consists of excavating a continuous overflow channel along the eastern edge of the project site. This design includes a proposed double- barreled culvert structure routing flows below the Twin Creeks Crossing. The Twin Creeks Crossing will serve as a main arterial connecting the development with Pacific Highway(State Highway 99), located to the east (see Figure 1). In addition,bank protection measures are proposed to stabilize the transition where Griffin Creek overflows into the Twin Creeks Development. Anticipated flood improvements associated with these features include lowered Base Flood Elevations (BFEs)and reduced 100-year floodplain and floodway extents, relative to effective conditions. This memorandum summarizes the approach and results of the technical analysis conducted by NHC for the Twin Creeks Development CLOMR. Background The Twin Creeks Development is located within a recently designated Special Flood Hazard Area (SFHA) between two separate flooding sources,Jackson and Griffin Creeks (see Figure 1). The SFHA, including regulatory floodway, were determined through detailed studies of Jackson and Griffin Creeks conducted by NHC for the City of Central Point(City)and FEMA as part of the Jackson County FIS(FEMA, 2011). Findings from these studies indicated that flooding in the area originates from overflow of Griffin Creek, immediately upstream of Pacific Highway,and continues to the northwest to merge with Jackson Creek. grater resource specialist 12 rifle Page 2 The reach connecting Griffin and Jackson Creeks within the development is referred to as the 'Jackson Creek Overbank'. III 916111 Cr'4 , `° :-.,,,,-;-:- '-- - *„,4-,— ,.„.. r-A,-. tiri,:-,It-,:-....,„_:....,,,..,.,.....,:41-7f.,::, -.. -a:1r* .;4' ., :,,-,.,.. 4 x 1 . ,Y ti 'a k. a.# ti o ' , ihr. µ 4a° f g " f •te r e =IC xY ,sF. Proposed Flood t y >- Channel :n l t , ! `� ` 3, ; r. s Alignment ; " k f '''',,q' ' } �,M"' f g a .` f+��F'' ^A ,YI�iRy .., I: }" r 7 .; =r- . .,4, ,. ,ti,„::::::::„.ma ` ,- kr_4 t•,,. a ,, i �j . 431.; st ,i ,:;„,. ....4.-,— ' ;,'.1,'„ ".;!';#:„..:„:'' '''' ir: ,.i.,,�` � � «.y 4.� 7�s�a 5 *'T 4 4^P' �' ��0t�... / r7 __1• l�„�'t x tlt ; er 1 Proposed Twin to— Creeks Culvert ; "`"�"� I �y�n l �� �,al! t. Crossing,.,. ,. ,._.. : ,, .�a Vic' ,w d` d'f`�", ,.i€+IN„ '� +{ '' ,� Proposed.at� a r 7, ', .i.,'f, ` Y�.,' a. �,. Bank t , l � , "`” s� - Protection w : x +yt• Sf n ra.t, . "a wpb -»- /14.x.5 � . t ?'fi •I ii_ „ ,:,i3,,, y, = # i al . ; t Ar^ r Effective Zone AE y .' r .�Y Y „Artily , EEffective Zone X t. v vs r.4 * 7, f at / t EffecitveFloodw 'a,: y i��d,i [. Figure 1 Effective FEMA flood hazard mapping and proposed Twin Creek flood Improvement measures, The effective floodplain mapping between the two study reaches,through the Twin Creeks Development,is broad and unconfined, resulting in a relatively wide floodway delineation. It should be noted that this reach does not receive perennial flow and would function as an overflow channel during 13 Page 3 infrequent, high magnitude flood events (there has been no observed flooding from Griffin Creek at the project site). Draft mapping for Griffin and Jackson Creeks was provided to FEMA in 2008, and the restudies of both creeks became effective when the Jackson County FIS was adopted by FEMA and Jackson County on May 3,2011. The Twin Creeks Development is a master plan community that precedes the most recent FEMA studies within the City. When construction of the Twin Creeks Development began, HC's as a detailed studies of Jackson and Griffin Creeks,the area was not mapped g prior SFHA. initiation n n NHC's continued while the technical analysis for the updated FIS was beingconducted(2 Development the City began using preliminary flood hazard mapping, (2006 to 2009).development.2009, Thereafter,construction within the Twin Creeks Development provided limited to areas ouside what is the effective floodway. To date, development within the Twin Creeks project site is compliant with both and City floodplain management regulations. snow oth CLOMR Submittal Information This memo contains appropriate supporting information for the CLOMR submittal. A narrative on the technical analysis is provided in the following text. Other supporting information prepared by NHC is provided in the appendices as follows: Appendix A. Certified Topographic Floodplain and Floodway Map Appendix B. Annotated FIRM Appendix C. Completed MT-2 Application Forms Appendix D. NFIP Regulatory Requirements, including a proposed example public announcement and notification letter for floodway revision Additional supporting information to be attached to this submittal includes: Conceptual-Level Flood Improvement Design Plans (provided by Whetstone Engineering) Endangered Species Act (ESA) Compliance Documentation (provided by the TCDC) Technical Analysis NHC completed several technical tasks for this CLOMR following FEMA MT-2 instructions and procedures. Model scenarios presented include a Duplicate Effective Model that replicates the water surface elevations in the effective Jackson County FIS, and a Revised Conditions Model simulating the proposed construction of the flood channel. Elevations specified in this memo are referenced to the NAVD 1988 vertical datum. Data Description Duplicate Effective Conditions NHC completed the most recent detailed'flood studies of Griffin and Jackson Creeks for the City and FEMA as part of the recently adopted Jackson County FIS(FEMA, 2011). As such,NHC already has possession of the duplicate effective hydraulic models for both Jackson and Griffin Creeks,as well as the 2006 City of Central Point LiDAR topographic data used for the floodplain mapping. These data were located in the Technical Support Data Notebook(TSDN)submitted to FEMA at the conclusion of the Jackson County FIS. 1 l Page 4 Revised Conditions Revised condition topographic data in the form of a master grading plan of the Twin Creeks Development were originally provided to NHC by Farber Surveying on May 30, 2008. The master grading plan consisted of a Triangulated Irregular Network(TIN)surface in AutoCAD format and included areas developed after the 2006 LiDAR was collected and while the effective FEMA study was being conducted from 2006 to 2009. Minor revisions to the master grading plan were subsequently made and provided to NHC by Whetstone Engineering on June 17,2014. A grading plan of the proposed overflow channel was provided to NHC by Whetstone Engineering on December 18,2012. NHC merged the original and revised master grading plans with that of the proposed overflow channel to construct a Revised Condition digital elevation model(DEM) in ArcGIS. The Revised Condition DEM includes a continuous flood(or overflow)channel and culvert structure at the Twin Creeks Crossing. The flood channel would connect with the existing detention pond adjacent to Griffin Creek and proceeding northward toward Jackson Creek. Physically,the flood channel terminates at a proposed detention pond at the northern limit of the Twin Creeks Development, but during a 100-year event this area will be inundated and drain overland toward the Scenic Avenue Bridge crossing to the west on Jackson Creek. The proposed flood channel would consist of a compound channel (see Figure 2). The top width of the proposed flood channel would range from 65 to 75 feet with approximately 20-foot wide flood benches located on either side of an existing 20-foot wide drainage swale. This swale was constructed between 2006 and 2009 and includes six approximately 2- foot high check dam structures located within the channel for stormwater treatment purposes. The culvert structure at Twin Creeks Crossing will consist of a pair of 18-foot wide, 9-foot tall CMP arch structures. Twin Creeks Crossing will serve as the primary arterial between the development and Pacific Highway. Bank protection measures are being proposed along the left bank of Griffin Creek. The measures were designed by Whetstone Engineering and consist of installation of two large woody debris (LWD)pieces at the upstream and downstream limits of existing rip-rap bank protection that is showing evidence of unraveling. Each LWD piece includes a trunk and root wad; however,only the root wad will be exposed in the channel as the trunk will be keyed into the existing bank and ballasted with rip-rap. The proposed bank protection measures are located within the Griffin Creek floodway;however, it is our understanding that they will be placed such that they will not cause a hydraulic impact. Trunks will be buried into the banks. Root wads that extend into the channel will blend in with the existing dense vegetation along the entire left bank. Furthermore,flood levels along this reach of Griffin Creek are primarily controlled by the constrictions at the railroad bridge and Pacific Highway culvert located immediately downstream. These crossing create a backwater and ineffective flow areas along the banks,further validating that these measures are not expected to substantially affect flood levels. Based on the factors presented above and engineering judgment,the proposed LWD bank protection features are not expected to have a definable adverse impact to flood levels on Griffin Creek. Conceptual-level flood improvement plans for the proposed channel,culvert structure and bank protection, prepared by Whetstone Engineering, are attached to this submittal. 15 Page 5 Jackson Creek Hydraulic Model Plan:Revised Floodplain 2/28/2013 River.,gWpn O.erbrN Rarn. 1251 t15 Upper Main RS.2e0.8 091--._______.+—.as —• 1'- - tA5 10DYR k G putl Inn:Ste I 12! ■ 1 \ : 246 \2 , 1244- 12Q o ' MI 00 —� Smm inl 150 �, Figure 3 Cross-section profile of proposed compound channel(River Station 2350.68) — Engineering Methods—Hydraulic Modeling General Model Description The Jackson Creek HEC-RAS hydraulic model includes the mainstem of Jackson Creek located to the west the Twin Creeks Development(see Figure 1), but also includes Jackson Creek Overbank reach which was used to compute flood levels within the Twin Creeks Development. As previously mention st waters enter the Jackson Overbank reach from Griffin Creek where overtopping mentioned clood urs upstream of Pacific Highway. Discharges escaping the Griffin Creek system and entering the Jackson Overbank reach were computed through a series of lateral structures within the HEC-RAS model for the 10-, 50-, 100-,and 500-year return periods. Discharges from the effective FIS were used for this CLOMR analysis and are given in Table 1. Table 1.Computed Flood Discharges Entering the Jackson Creek Overbank Reach from Griffin Creek (FEMA, 2011). Return Period l0-year 50-year 100-year Discharge(cfs) 122 500-year 2a 1850 Duplicate Effective and Revised Condition HEC-RAS models are being submitted as part of this CLOMR analysis. Two HEC-RAS 'plans'are associated with each modeled condition: a Floodplain and Floodway plan. Separate Floodplain and Floodway plans were developed because changes to the geometry files were necessary to perform the encroachment analysis (e.g. turning off optimization of lateral weirs). Duplicate Effective Model The effective model is available, as previously discussed; however, it was developed using HEC-RAS Version 3.1.3. The effective model was re-run in HEC-RAS Version 4.1.0 for the CLOMR analysis and the 100-year and Floodway simulations have been reproduced within 0.01 feet at FEMA lettered cross- sections C through N (Table 2). Differences at cross-section A and B are a maximum of 0.23 feet and are the result of late modifications made to the Jackson Creek model that did not get incorporated into the adopted Jackson County FIS(FEMA,2011). 16 Page 6 The Duplicate Effective Model consists of the entire Jackson Creek HEC-RAS model, including the Jackson Creek Overbank reach,which spans the area proposed to be physically modified by the project. The effective Jackson Creek Overbank reach contains a total of 16 cross-sections, 14 of which are lettered(A to N)as shown in Appendix B. The upstream and downstream limits of the Jackson Creek Overbank reach are delineated by study break lines. Therefore, changes on the Overbank Reach do not propagate upstream and impact conditions in Griffin Creek as long as the submergence of the lateral structures does not change. Downstream,the Jackson Overbank reach ties into the mainstem of Jackson Creek between cross-sections D and E. Revised Condition Model The Revised Condition Model was created by adding the proposed flood channel and twin barrel culvert structure combined with the revised condition grading plan mentioned in the Data Description section. A total of 33 new cross-sections were inserted into the Jackson Overbank reach in the Revised Conditions Model to augment the 16 cross-sections in the Duplicate Effective Model(see Appendix A). The new cross-sections were added to:: • Extend the model to include the entire development • Represent geometries of the six existing check-dam structures • Include geometry of the Twin Creeks Crossing culvert structure • Represent geometry of the proposed check-dam structure at the outlet of the upstream detention pond An additional modification made to the Revised Condition Model included splitting the Jackson Creek Overbank reach into parallel reaches between effective cross-sections I and N, to separately compute flood levels between the proposed flood channel and the left overbank. The most prominent difference between the Duplicate Effective and Revised Condition models is the downstream extension of the floodway in the latter. Three additional cross-sections were added downstream of effective Cross-Section A on the Jackson Overbank Reach to represent extension of the flood channel and routing of flood waters westward through a proposed open space in the development. The confluence of the Jackson Overbank floodway still occurs between cross-section D and E on Jackson Creek, but the reach length between was increased due to the additional cross- sections and longer flow path. To account for the added reach length,the floodway width at the downstream limit of the reach was expanded from 220 to 260 feet. As mapped,the Revised Condition floodway overlaps effective Cross-Section D on Jackson Creek; however,this portion of the cross-section is ineffective due to the influence of the Scenic Avenue road embankment downstream. In addition to the widening and shifting north of the floodway connection between Jackson Overbank and Jackson Creek,a portion of the effective floodway along the southern edge would be deleted as part of the proposed revision. The proposed floodway realignment,from a diagonal to angular alignment,would also require that a portion of the effective floodway be removed (see Appendix A). 17 Page 7 Table 2. Comparison of Effective FIS to Duplicate Effective Water Surface Elevations for th and Floodway Simulations. the 100-year Effective Fly Cross- Section 100-year Flora d;►Cain Roadway w? 4 v'f 4 R(HEC-MS v 4r> > c Statian in t; ' 41' (Le ,�, w Pa renthesis) to Zr.: q 6y A. (793.2) 1238.36 1238,49 -0.11 8 (951,f1) 1238.61 1238.84 -0.23 . 1239.18 1139..E8 0.00 f(1188.3) 1239.72 1239.60 1.?:3'��t 0� 1240.75 �� 1240.56 1240.58 0,00 D(1554.$) 1240.75 124 E(1689.0) 1241.82 1241.81 0.01 1242.55 242...5 Q,00 F(1966.3) 1242.82 1242.82 0.00 Q,QO 6' 1243.76 1 (2113.1) 1243.65 1243.65 0.00 ;44,3 35 Q,QQ 1 ff(2270.1) 1244.36 1244,37 -0.01 44,54 1244.x4 Q,OQ 1245.29 1 1(2422.0) 1245.25 1245.25 0.00 45..29 0� 1 .1(2548.0) - 1245.86 1245.97 1245.97 Q.00 , K(3071.0) 1248.35 124834 0.01 1249.25 1249.25 0.00 1.(3454.7) 1250.99 1250,99 0.00 0.00 1251.94 1251 M(3722.3) 1252.21 1252.21 0.00 94 0,00 1253.18 1243 ' N(3956.5) 1254.01 1254,01 .18 0.00 0.00 1254.05 1254.05 0.00 Overall,the Revised Condition Model shows reductions in flood levels along the entire Jackson Creek Overbank reach compared to the effective conditions (Table 3). The upstream and downstream limits of the Jackson Creek Overbank reach are delineated by study reach breaklines, between Griffin Creek an the mainstem of Jackson Creek, respectively. Downstream,the Revised Condition Model simulates and effective conditions to within 0.38 feet, which is within the 0.5 foot threshold specified by FEMA. Upstream, the proposed work within the Twin Creek Development will not impact the quantity of overflow entering the project (Table 1), thus changes to BFEs will not propagate upstream into Griffin Creek and the flood hazard boundaries are effectively tied-in at the study breakline between the two reaches. Table 4 tabulates the FEMA Floodway Data Table information from the Revised Model. 8 Page 8 Table 3, Comparison of Duplicate Effective and Revised Conditions. River Station 100-Year Floodplain IRoodway Efteotive Rewised l[FE10 mss,- , u ` eitita1,V C LT to t ,�: 0 v c a o c es u u• as H w H G3 .� 4 ca: - 0.15 - 1237.79 - 1238.68 - 01 - 1237.98 - - 1238.73 - 0.25 - 1237.94 1238.67 • 753.2(A) 0.2.3 1238.49 1233.34 -0.15 1239.18 1238.89 -0.29 951.8(8) 160.54 1238.84 1238.48 -0.36 1239.60 1239.08 -0.52 232,77 - 1238.51 - 1239.16 - - 247.95 - 1238.53 - - 1239.17 - - 265.49 - 1238.54 1239.26 1188.3(C) 401.53 123932 1238.63 -1.09 1240.56 2239.56 -1.00 - 579.14 - 1239.28 - - 1239.99 - - 706.95 - 1239.65 - - 1240.42 - - 71152 - 1239.70 - - 1240.38 . 731.28 - 1240.03 1240.63 15542(D) 733.83 124075 124019 -0.56 1241.33 1240.86 -0.47 1689.0(E) 1002.15 1241.81 1241.41 -0.40 1242.55 1241.74 -0.81 - 11172 - 1241.92 - - 1242.26 .• - 1187.03 - 1242.22 - - 1242.63 - - 1200.04 - 1242.32 - - 1242.58 - - 1211.98 - 1242.47 1243.01 1966.3(F) 1249.04 1242.82 1242.58 -0.24 1243.76 1243.27 .0.49 2113.1(G) 1358.7 1243.65 1243.19 -0.46 1244.54 1243.73 -0.81 2110.1(K) 1495.18 124437 1243.93 -0.44 1245.29 1244.28 -1.01 2422.0(I) 1646.26 1245.25 1244.75 -0.50 1245.97 1244.94 -1.03 - 1664.09 - 1244.90 - - 1245.04 - 1671.51 - 1244.91 - - 1245.03 - - 1691 - 1245.41 - - 1245.44 2548.0(1) 175749 1245.86 1245.69 -0.17 1246.71 1245.80 -0.91 - 1866.28 - 1246.13 - - 1246.27 - 2019.16 - 1246.92 - - 1247.08 - 2138.75 • 1247.67 - - 1247.79 - - 2153.71 - 1247.57 - - 1247.70 - 307L0(14) 2178.49 , 1248.34 1248_33 -0.01 1249.25 1248.43 -0.82 - 2350.68 - 124915 1249.28 - 3454.7(1) 2564..28 1250.99 125011 -0.88 1251.94 1250.23 -1.71 2611.46 - 1250.37 - - 1250.49 - 2626.62 . - 1250.38 - - 1250.50 - 2642.965 1250.76 - - 1250.89 - - 2673.75 1250.81 - - 125094 - 2732.76 1250.86 - 1250.98 3721.3(64) 2832.34 . 1252.21 1251.22 -0.99 1253.18 125135 -1.83 - 2865.01 - 125136 1251.49 - 2927.39 - 1251.79 • 1251.94 3048.78 1252.8 . - 1253.416 3956.5(s) 3067.82 1254.0 1252.83 -1.18 1254.05 125108 -0.97 - 311036 1252.85 1253.10 3143.45 1252.97 - 1253.23 . - 3141.92. 1253.41 1253.66 - 3355.18 - 1253.29 1253.55 337037 - 1253.65 3253.85 - 3639.01 1254.33 - 1254.53 19 Page 9 Table 4. Revised Floodway Information. Ef ertnie RAa River Station(F[lk� Cintr_,s- Rear ise�f Serf- iota,in RAS Width Area(sq 114ezn W itihorat With parenthi5,aaa River (feet) ft) Velocity Fd akaay Fi at Increase aprprotrrrate) Station (hlsmc) (feet) (feet) (facet) 0.15 255 821 .1.5 0.20 255 1232.8 1238.7 0,9 - 0.8 1238.0 1238.7 0.8 0.2.5 7g 342 3.4 1237.9 1233.7 0.7 793,2 G41 028 65 951.8(8) 160.54 65 329 3.5 12311.3 1139..9 0.6 " 2.32.77 65 307 3.1 113,8.5 11.39..1 C4.6 232.7 4.0 1233.5 1239,2 28.3 4.3 1233.5 0.7 265.49 66 302 1239,2 0.fi 1188.3(C) 401.53 64 4.1 1238, 123.9.3 275" 579.14 64 243 4.4 113$.6 1239,6 00:97 9 706.55 64 S.0 1239.3 1240,0 0.7 718.95 240 5.1 1239. 63 204 124!1.4 0.8 ` 731.28 63 6.0 123'4.7 124114 1554.8 q 238 5.1 1240.0 0.7 ( ) 783.33 63 232 12a0.ty a.7 1689.0(E) 10112.15 63 5.3 1240.2 1240.9 1117.8 64 223 5.5 1241.4 0.3 211 1242.3 0.3 - 1187.03 63 5.8 1241.9 1242.3 0.3 - 1287.03 63 i 09 5.8 1242.1 1242.6 0.4 1211.04 64 7.0 1242.3 1242.6 0.3 1966.3(F) 1249.04 222 5.5 1242.5 1243.0 0.5 69 237 5.1 1242.6 1243.3 0.7 2113.1(6) 1358.7 72 2270.1(6) 1 1358.7 78 244 5.0 1243.2 1243.7 0.5 2270.0(I4 1495.28 78 245 5.0 1243.9 1244.3 220 5.5 1244.8 0.3 1664.09 77 219 1244.9 0.1 ` 1677.51 76 5.6 1244.9 1245.0 0.1 186 6.6 1244.9 1245.0 - 1691.00 76 239 5.1 0.0 2548.0(1) 1757.49 76 1245.4 1245.4 0.0 �� 5.0 1245,7 1245.8 0.1 1866.28 77 5.3 " 2019.16 74 1246.1 1246.3 0.1 218 5.6 1246.9 1247.1 - 2138.75 75 213 5.6 1247.7 0.2 - 2153.71 g0 1247.8 0.1 3071.0 K 168 7.3 1247.6 1247.7 ( ) 2178.49 75 244 0.I. ` 2350.68 76 5,0 12483 1243.4 0.1 3454.7 ! 241 5.1 1249.2 1249.3 () 2564.28 74 226 0.1 - 2611.46 73 236 5.4 1250.1 1250.2 0.1 2626.62 73 206 5.2 1250.4 1250.5 0.1 2626.62 5.9 1250.5 75 12513.4 r 0.1 254 4.1 1250..8 1250,9 - 2673.75 68 270 4.5 1250.8 0.1 2732,76 52 209 1251,0 0.1 3712.3(M) 2332.34 49 S.3 1250.9 1251,0 0.1 - Y93 6,3 1251,2 1251,4 0.1 2865.01 42 191 6.4 ' 2927.39 42 236 5,2 1251...4 1251,5 0.1 2927.38 1251.8 1251.9 3355.5(FF) 3068.78 42 278 4.4 125.2,3 1253,1 0.3 43 272 1252.8 1253,1 0,3. 4.5 311.0.56 43 242 5.1 12.5.2.9 1253.1 0,3 . 3143.45 49 255 0.3 ` 3343.42 52 4.7 115:3.0 12512 0.3 275 ,18 49 213 ' 31'55 4.4 1253,4 12517 0,3 1355.57 54 Si 1251..3 1153.6 0,3 281 4..3 1253.3 12515 3639.01 66 265 01.1 4.6 1254.3 1254,5 �.z 0 Page 10 Notification This CLOMR lowers BFEs, reduces the extent of the 100-year floodplain, and proposes to narrow the floodway. In order to comply with NFIP and FEMA standards and policy for a proposed floodway revision,the FEMA MT-2 instructing state that the community can either be alerted through a published public announcement or individual letters sent to affected landowners. Examples of the proposed public announcement and notification letter for floodway revision are provided in Appendix D. Following acceptance of the language in these documents one or the other will be used to alert the community of the proposed project. Compliance with Endangered Species Act The TCDC has completed environmental permitting that documents that the project does not "take"or harm endangered species and is therefore in compliance with the Endangered Species Act. The relevant ESA compliance documentation, provided by the TCDC, is attached to this submittal. References Federal Emergency Management Agency(FEMA). 2011. Flood Insurance Study,Jackson County, Oregon and Incorporated Areas. Flood Insurance Study Number 41029V000A. May 3. Northwest Hydraulic Consultants (NHC). 2008. Hydraulic Summary,City of Central Point,Jackson County, Oregon. Document prepared for Michael Baker Jr. Corp. July 10. ►y 1 Appendix A. Certified Topographic Floodplain and Floodway Maps P 22 h.0 i t }`t - • i a• •!:;_ :_ 'z // - 1• y L i i >o _- I !. � � ' ;�- r\ _Jt i - , is w I "4n f J p ip a., 1/. 7.-"f_"' ,I .. E Y + - J N•,..e..n.. qrcn .' il s. egend �.. t Effective Study Breakline - r Revised Cross-Sections - _ -- '` $.1. 111 ,4A . Revised Base Flood Elevation - j,' 1� / �i )1 \ �/: )� Revised Profile Beeline - \ + '.G i1 Revised Floodway - - _ Revised Floodway(Removed) p � \�`� `, x y•�'Revised Zone AE '•\ it __J Revised Zone AH Revised Zone X T-- - _ - Effective Cross-Section _ - - - - Effective Base Flood Elevation _i --- - -_. Effective Profile Baseline 't, i — C i r�'Y Twin Creeks Development Boundary A 1 e _ ? \ ;r -__ rY( PPros n & _ -- City Boundary .. . . v � -. _ s E Effective Zone AE - 1 fi ,. . .;Effective Zone - - - - -- -- I Effecitve Floodway _. - '- -"� - - �.. - Taslots Revised Grading Contours � --- ---_. r t et:tt,'In mm� Z:41.na%.61.q NTm.,eiNEwnamnq - pmnapwnnNNOJJOmeenWlap4na6ewn,nrROmaib,um a.e Nwp9p i.`1el, 1%In(WA.Om eWpmeni 11,(1\IN EMae maYRW an.n,tmu from R•xmnarv6,R�Inp.w e.NNC n3op9 / .;:ti'...../././t1,Fl fax pi bu Rm ,Je.ae•Cava, �:( 1trm.y ,'' \i, Jackson Creek Overbank ����/' Workmap Al F.NI yMs�'y .I 4,.A.11`ya'Y" bole 1 3.IO4 l 'rT- a .......-: 5os969 2 iF.#'": l' AllillWriggrallir-411111Mitii4 fillialliiill"...- lir 1 LIMB OF ,t - ' O ETAILED STU•V O !4 ! 7= T.36 S. ZONE AE ' .. 1235 ' �� ` pARKwOOD AVENUE '. .Avenue Bridge -�--'� vim .... 1r© T.37 S. - se930°°m N N .. - �-' vs- - �_ —�'��FLOODWAY-CON7AINE.-IN.CNgNN L p �'Tie to Effective 1234; }RZS. - .1 _ a,o. ;. 123 0..•,�In 129.. . t Prime Bridge -_ '_..- . ..:7.- i a ,r� „ 112 Tie to Effective �5 '�2' 1Za! _ 4 Floodway �y "i;2 r :,,'°*40-1 r .„'r hWLSOO►(4 �,• 45 S 5 �fi i L,� 1 'C 11�+' '�' y „3 1 t( t © JACKSON COU .f. f- ,a,- 4 r�,..:111,,,,i:°'A ,„. .4 7. -h` t t - 1242 UNINCORPORATED A .� Remove Effective , ti �'r ;?r5 '..u ' -4 `f` �z1 r'f -1, ` ', ;- Floodway y .R ,.4k - •yey.s, �k� � r mien Structure Al, et9ta^���=,.--. 2...3 7 RINCESS ro JW 415..9 ` ^. (, ..- •O , Y 74.4X-r14; � '++ �� PRINCESS 0 ,, ,, .,, 1,/,,...,..",-free,40;4:4):N A A.:".---1 .:0•.ev� `- 7 y+ T 0 I.• .....:44, .. ii.... 1 .•�' � � s %w 2 d .Lim.' F rPdWi►'A / nA 77#r �md0' r 0 11414 147 Ridge• .•_. ,,, ,,„.• ...,r, Noy 4,Iiiiiv.;1 ,,... ,,sv:., ,,,,,,,:.,, ,., ,: ._, 71,...,,,..,,,,...,!roe",:„,,41%.ix.1, At' ''; 4.,7,711.1171221.111111k J � ;.'1 �i� 256 t?'-�� ;�_did GROU' R ZM yyt ��, n` it Tie to Effective F 1009 nein Creeks Cress • I. �x ,`` .�,�,-. 469266an N 1?50 " ty:. 001.17:E.,5.2.., sc , 0 GAr,ia ,l a 1Q ti ZONE Jackson Creek 0 r A 1253 ®= 1 4' ;e'9' r i 4 \v AE VIM �a r QJ......4-#401.':,OliivE 0 1254 - j ' O I J 55 ,N, ?s. i.t e�,t o t NZ0214 ANHORN ROAD ;�:1257 STEAM• DRIVE BLU Tie to Effective 126r raitatuor ii PROFILE BASE LINE *1411P, ��/ JACKSON COIINTI I ,d 258 GRIFFIN .- O UNINCORPORATED AREAS 1ULANE AVENUE 415569 ,259 w —����. 'i, ZONE t 1 c c o b i . 9 r.°°y'� 1262 Itia tiLv.91' w BLACK OAK DRIVE ( 6 1265 k r'ijfin Creek 42'22'30.0" '^ j`�. 4 '. }j,y^1rr{rs 122'58'15 D' © 0 1264 JACKSON COUNTY JOINS PANEL H0171 creek PROFILE BASE LINE 4265000 FT UNINCORPORATED AREAS 415589 Legend Effective Study Breakline Revised Jackson Creek Overbank Profile Baseline EZRevised Floodway Twin('reeks Development CLOMR Revised Zone AH Revised Zone AE Revised Zone X Jackson Creek Overbank Annotated FIRM 41029C 1768E Scale-1:6,000 `' soo 2so ° soo Feet -tile � Floodway_Removal coon/cyst.:UTM Zone ION hors datum NAD 63 nor:units feet northwest hydraultc casMtents project no 206041 27-Jo1-2014 9 505966 Ayr Appendix C. Completed MT-2 Application Forms 2 6 w U.S.DEPARTMENT OF HOMELAND SECURITY FEDERAL EMERGENCY MANAGEMENT AGENCY OVERVIEW& CONCURRENCE FORM Erp re r February 28.1660-0016 2014 IPAPERWORK BURDEN DISCLOSURE NOTICE Public reporting burden for this form is estimated to average 1 hours per response.The burden estimate includes the time for reviewing instructions, searching existing data sources,gathering and maintaining the needed data,and completing,reviewing,and submitting the form.You are not required to respond to this collection of information unless it displays a valid OMB control number.Send comments regarding the accuracy of the burden estimate and any suggestions for reducing this burden to:Information Collections Management,Department of Homeland Security,Federal Emergency Management Agency, 1800 South Bell Street,Arlington,VA 20958-3005,Paperwork Reduction Project(1660-0016).Submission of the form is required to obtain or retain benefits under the National Flood Insurance Program.Please do not send your completed survey to the above address. PRIVACY ACT STATEMENT AUTHORITY:The National Flood Insurance Act of 1968,Public Law 90-448, as amended by the Flood Disaster Protection Act of 1973,Public Law 93- 234. PRINCIPAL PURPOSE(S):This information is being collected for the purpose of determining an applicant's eligibility to request changes to National Flood Insurance Program(NFIP)Flood Insurance Rate Maps(FIRM). ROUTINE USE(S):The information on this form may be disclosed as generally permitted under 5 U.S.0§552a(b)of the Privacy Act of 1974,as amended.This includes using this information as necessary and authorized by the routine uses published in DHS/FEMA/NFIP/LOMA-1 National Flood Insurance Program(NFIP);Letter of Map Amendment(LOMA)February 15,2006,71 FR 7990. DISCLOSURE:The disclosure of information on this form is voluntary;however,failure to provide the information requested may delay or prevent FEMA a determination regarding a requested change to a(NFIP)Flood Insurance Rate Maps (FIRM . A. REQUESTED RESPONSE FROM DHS-FEMA This request is for a(check one): ® CLOMR: A letter from DHS-FEMA commenting on whether a proposed project,if built as proposed, would justify a map revision,or proposed hydrology changes(See 44 CFR Ch. 1,Parts 60,65&72). ❑ LOMR: A letter from DHS-FEMA officially revising the current NFIP map to show the changes to floodplains, regulatory floodway or flood elevations.(See 44 CFR Ch. 1,Parts 60,65&72) B. OVERVIEW 1. The NFIP map panel(s)affected for all impacted communities is(are): Community No. Community Name State Map No. Panel No. Effective Date Example:480301 City of Katy TX 48473C 0005D 480287 Harris County 09/28/90 410092 City of Central Point OR 402C 768F 05/03/11 OR 4110299 1 C 1768F 05/03/11 2. a. Flooding Source: b.Types of Flooding: ®Riverine ❑Coastal ❑Shallow Flooding(e.g.,Zones AO and AH) ❑Alluvial fan ❑Lakes ❑Other (Attach Description) 3. Project Name/Identifier:Twin Creeks Development 4. FEMA zone designations affected:AE,X (choices: A,AH,A0,A1-A30,A99,AE,AR,V,V1-V30,VE,B,C,D,X) 5. Basis for Request and Type of Revision: a. The basis for this revision request is(check all that apply) ®Physical Change ❑Improved Methodology/Data ®Regulatory Floodway Revision ❑Base Map Changes ❑Coastal Analysis ®Hydraulic Analysis ❑Hydrologic Analysis ❑Corrections ❑Weir-Dam Changes ❑Levee Certification ❑Alluvial Fan Analysis ❑Natural Changes ®New Topographic Data ❑Other(Attach Description) Note: A photograph and narrative description of the area of concern is not required,but is very helpful during review. FEMA Form 086-0-27,(2/2011) Previously FEMA Form 81-89 MT-2 Form 1 Page 1 of 3 27 I ■ b. The area of revision encompasses the following structures(check all that apply) Structures: l ❑Levee/Floodwall _ I evee/Floodwall ®Bridge/Culvert { ❑Dam 0 Fill ❑Other (Attach Description) i 6. ®Documentation of ESA compliance is submitted(required to initiate CLOMR review). Please refer to the instructions for more information. C. REVIEW FEE Has the review fee for the appropriate request category been included? ❑ Yes Fee amount: $0 Please see the DHS-FEMA Web site at9riC1 Aiwa tuna v,+i�d.- . ,,a ® No,Attach Explanation { cY A�4Af W'fiGAfIMrY(~rb;1_fF!tts_SIt:tSe for Fee Amounts and Exam.lions. D. SIGNATURE All documents submitted in support of this request are correct to the best of my knowledge. I understand that any false statem fine or imprisonment under Title 18 of the United Stales Code,Section 1001. ant may be punishable by Name: Bret Moore Company: Twin Creeks Development Co.,LLC Mailing Address: Daytime Telephone No.: Fax No.: E-Mail Address: Signature of Requester(required): Dale; As the community official responsible for floodplain management,I hereby acknowledge that we have received and reviewed this L (LOMB)or conditional LOMB request. Based upon the community's review,we find the completed or proposed project meets or is designed to meet all of the community floodplain management requirements,including the requirements for when fill Is placed In the regulatory floodway,and that all Revision necessary Federal,State,and local permits have been,or in the case of a conditional LOMR,will be obtained. For Conditional LOMR requests,the applicant has documented Endangered Species Act(ESA)compliance to FEMA prior to FEMA's review of the Conditional LOMR application.For LOMR requests,I acknowledge that compliance with Sections 9 and 10 of the ESA has been achieved independently of FEMA's process, For authorized,funded,or being carried out by Federal or State agencies,documentation from the agency showing its compliance with Section 7 a 2 of the ESA will be submitted. In addition,we have determined that the land and any existing or proposed structures to be removed from the SFHA actions re or will be reasonably safe from flooding as defined in 44CFR 65.2(c),and that we have available upon request by FEMA,all analyses and OO documentation used to make this determination, } I Community Official's Name and Title: Community Name: Mailing Address: Daytime Telephone No.: Fax No.: E-Mail Address: Community Official's Signature(required): Date: CERTIFICATION BY REGISTERED PROFESSIONAL ENGINEER AND/OR LAND SURVEYOR This certification is to be signed and sealed by a licensed land surveyor,registered professional engineer,or architect authorized by law to certify elevation information data,hydrologic and hydraulic analysis,and any other supporting Information as per NFIP regulations described in the MT-2 Forms Instructions. All documents submitted in support of this request are correct to the best of my knowledge. I understand that ` any false statement may be punishable by fine or imprisonment under Title 18 of the United States Code,Section 1001, paragraph 65.2(b)and as .wa-`:r...s'-..u:..aww -y....ra,.nWy,,�•y+3W.,.y:'fnMln.• Certifier's Name: Peter Brooks . .. . Date: License No.: 87092PE / --_— _ Expiration Date: 12/31/15 Company Name: Northyvp4t ydra lrGtionsul.tgrit- ---- __ _ ` Telephone No 206-241-6000 t ) , -- — --�— Fax No 2 06-439.242 Signature: J / f - 0 Date: .�1.(,1 E-Mail Address: pbrooks.nhcweb.com 9u ITMA Foim 086-0-2./.(2/2011) v Previously FEMA Form 81-89 MT-2 Form 1 Page 2 of 3 •::ttYa*... s+rsia3+• r �...;.skar-Jiw..i...yle...} .a..'..:.. ;_ _...,, .c:...+d`.....xw, .,l:.. Ensure the forms that are appropriate to your revision request are includes ed in your submittal Form Name and(Number) "{ur'- - r ; Required if... �:) , :1/41(s It f 1_:. }7 ® Riverine Hydrology and Hydraulics Form(Form 2) New or revised discharges or water-surface elevations X4:...),:7.'\ ❑ Riverine Structures Form(Form 3) ( ) Channel is modified,addition/revision of bridge/culverts, f�/: f 1 addition/revision of levee/Iloodwall,addition/revision of dam �?:r �/ , ❑ Coastal Analysis Form(Form 4) New or revised coastal elevations f,';F y„, "�'��<<?!c ❑ Coastal Structures Form(Form 5) Addition/revision of coastal structure �'' " ' + )� "s4a Odt ❑ Alluvial Fan Flooding Form(Form 6) Flood control measures on alluvial fans f EXPIRES: - I 7 0 J FFMA Form 006-0-27,(2/2011) Previously FEMA Form 81.130 M1-2 For 1 Page 3 of 3 Form 1,C. Review Fee—Explanation No review fee is attached because this as this submittal is an amendment to a previously submitted, still active, CLOMR application. A fee of$4,400 was paid by the Twin Creeks Development Company and p y in 2013 for the original submittal. Relevant project identifier information is provided below: LLC Case No.: 13-10-0914R Community: City of Central Point, OR Community No.: 410092 Requester: Peter C. Brooks, P.E. Identifier: Twin Creeks Development Flooding Source: Jackson Creek Overbank FIRM Panel Affected: 41029C1768F . U.S.DEPARTMENT OF HOMELAND SECURITY FEDERAL EMERGENCY MANAGEMENT AGENCY O.M.B No. 1660-0016 RIVERINE HYDROLOGY & HYDRAULICS FORM Expires February 28,2014 PAPERWORK BURDEN DISCLOSURE NOTICE Public reporting burden for this form is estimated to average 3.5 hours per response.The burden estimate includes the time for reviewing instructions, searching existing data sources,gathering and maintaining the needed data,and completing,reviewing,and submitting the form.You are not required to respond to this collection of information unless a valid OMB control number appears in the upper right corner of this form.Send comments regarding the accuracy of the burden estimate and any suggestions for reducing this burden to: Information Collections Management,Department of Homeland Security,Federal Emergency Management Agency, 1800 South Bell Street,Arlington VA 20958-3005,Paperwork Reduction Project (1660-0016). Submission of the form is required to obtain or retain benefits under the National Flood Insurance Program.Please do not send your completed survey to the above address. PRIVACY ACT STATEMENT AUTHORITY:The National Flood Insurance Act of 1968,Public Law 90-448,as amended by the Flood Disaster Protection Act of 1973,Public Law 93-234. PRINCIPAL PURPOSE(S):This information is being collected for the purpose of determining an applicant's eligibility to request changes to National Flood Insurance Program(NFIP)Flood Insurance Rate Maps(FIRM). ROUTINE USE(S):The information on this form may be disclosed as generally permitted under 5 U.S.0§552a(b)of the Privacy Act of 1974,as amended.This includes using this information as necessary and authorized by the routine uses published in DHS/FEMA/NFIP/LOMA-1 National Flood Insurance Program(NFIP);Letter of Map Amendment(LOMA)February 15,2006,71 FR 7990. DISCLOSURE:The disclosure of information on this form is voluntary;however,failure to provide the information requested may delay or prevent FEMA frprocessing a determination regarding a requested change to a NFIP Flood Insurance Rate Maps (FIRM). -.Flooding Source: Jackson Creek Overbank Note:Fill out one form for each flooding source studied A. HYDROLOGY 1. Reason for New Hydrologic Analysis (check all that apply) ® Not revised(skip to section B) ❑ No existing analysis ❑ Improved data ❑ Alternative methodology ❑ Proposed Conditions(CLOMR) ❑ Changed physical condition of watershed 2. Comparison of Representative 1%-Annual-Chance Discharges Location Drainage Area(Sq.Mi.) Effective/FIS(cfs) Revised(cfs) 3. Methodology for New Hydrologic Analysis (check all that apply) ❑ Statistical Analysis of Gage Records ❑ Precipitation/Runoff Model 4 Specify Model: ❑ Regional Regression Equations ❑ Other(please attach description) Please enclose all relevant models in digital format,maps,computations(including computation of parameters),and documentation to support the new analysis. 4. Review/Approval of Analysis If your community requires a regional,state,or federal agency to review the hydrologic analysis,please attach evidence of approval/review. 5. Impacts of Sediment Transport on Hydrology Is the hydrology for the revised flooding source(s)affected by sediment transport? ❑Yes ❑No If yes,then fill out Section F(Sediment Transport)of Form 3. If No,then attach your explanation.. 31 FEMA Form 086-0-27A,(2/2011) Previously FEMA Form 81-89 MT-2 Form 2 Page 1 of 3 1 B. HYDRAULICS 1. Reach to be Revised Description Cross Section Water-Surface Elevations(ft) Downstream Limit' _Jikson Ov i-bank d/s reach Effective Proposed/Revised limit A Upstream Limit* acr on Overbank u/s rea h —at 1238 4g 1238.3_ ties i hrPaklina n/—�_ n/n/._ 'Proposed/Revised elevations must tie-into the Effective elevations within 0.5 foot at the downstream and upstream limits of revision. 2. Hydrauli Method/Mod I Used: HEC-RAS 4.1.0 3. Pre-Submittal Review of Hydraulic Models" DHS-FEMA has developed two review programs,CHECK-2 and CHECK-RAS,to aid in the review of HEC-2 and HEC-RAS hydraulic models, respectively. We recommend that you review your HEC-2 and HEC-RAS models with CHECK-2 and CHECK-RAS. 4. Models Submitted Natural Run File Name: Floodvg Run Duplicate Effective Model' Plan Name: File Name: Datum JAFISOct04.P10 DupEffect Floodplain JAFISOct04.P15 pffe Name: y Corrected Effective Model' File Name: Plan Name: Du Effect Floodway _NAVD88 File Name: Plan Name: Existing or Pre-Project File Name: ----- Conditions Model Plan Name: File Name: _ Plan Name: Revised or Post-Project File Name: �: ---_-____ Conditions Model Plan Name: File Name: JAFISOct04.P17 Revised Floodplain JAFISOct04.P20 Plan Name: Other-(attach description) File Name: Plan Name: Revised Floodway NAVD88_ File Name: Plan Name: 'For details,refer to the corresponding section of the instructions. ® Digital Models Submitted?(Required) C. MAPPING REQUIREMENTS A certified topographic work map must be submitted showing the following information(where applicable):the boundaries of the effective,existing, and proposed conditions 1%-annual-chance floodplain(for approximate Zone A revisions)or the boundaries of the 1%-and 0.2%-annual-chance floodplains and regulatory floodway(for detailed Zone AE,AO,and AH revisions);location and alignment of all cross sections with stationing control indicated;stream,road,and other alignments(e.g.,dams, levees,etc.);current community easements and boundaries;boundaries of the requester's property;certification of a registered professional engineer registered in the subject State;location and description of reference marks;and the referenced vertical datum(NGVD,NAVD,etc.). ED Digital Topographic Information: Proposed .radin. elan 1-foot con ourrs Mapping(GIS/CADD)Data Submitted(preferred) Source: Grading plan from Whetstone Engineering Date: 12/18/12.06/17/14 Accuracy: Note that the boundaries of the existing or proposed conditions floodplains and regulatory floodway to be shown on the revised FIRM and/or FBFM must tie-in with the effective floodplain and regulatory floodway boundaries.Please attach a copy of the effective FIRM and/or FBFM,at the same scale as the original,annotated to show the boundaries of the revised 1%-and 0.2%-annual-chance floodplains and regulatory floodway that tie-in with the boundaries of the effective 1%-and 0.2%-annual-chance floodplain and regulatory floodway at the upstream and downstream limits of the area on revision. ® Annotated FIRM and/or FBFM(Required) 32 FEMA Form 086-0-27A,(2/2011) Previously FEMA Form 81-89 MT-2 Form 2 Page 2 of 3 D. COMMON REGULATORY REQUIREMENTS* 1. For LOMR/CLOMR requests,do Base Flood Elevations(BFEs)increase? ❑Yes 18] No a. For CLOMR requests,if either of the following is true,please submit evidence of compliance with Section 65.12 of the NFIP regulations: • The proposed project encroaches upon a regulatory floodway and would result in increases above 0.00 foot compared to pre-project conditions. • The proposed project encroaches upon a SFHA with or without BFEs established and would result in increases above 1.00 foot compared to pre-project conditions. b. Does this LOMR request cause increase in the BFE and/or SFHA compared with the effective BFEs and/or SFHA? If Yes,please attach proof of property owner notification and acceptance(if available). Elements of and examples of property o❑w err notifications can be found in the MT-2 Form 2 Instructions. 2. Does the request involve the placement or proposed placement of fill? ❑ Yes ® No If Yes,the community must be able to certify that the area to be removed from the special flood hazard area,to include any structures or proposed structures,meets all of the standards of the local floodplain ordinances,and is reasonably safe from flooding in accordance with the NFIP regulations set forth at 44 CFR 60.3(A)(3),65.5(a)(4),and 65.6(a)(14). Please see the MT-2 instructions for more information. 3. For LOMR requests,is the regulatory floodway being revised? 0 Yes 0 No If Yes,attach evidence of regulatory floodway revision notification. As per Paragraph 65.7(b)(1)of the NFIP Regulations,notification is required for requests involving revisions to the regulatory floodway. (Not required for revisions to approximate 1%-annual-chance floodplains (studied Zone A designation)unless a regulatory floodway is being established.Elements and examples of regulatory floodway revision notification can be found in the MT-2 Form 2 Instructions.) 4. For CLOMR requests,please submit documentation to FEMA and the community to show that you have complied with Sections 9 and 10 of the Endangered Species Act(ESA). For actions authorized,funded,or being carried out by Federal or State agencies,please submit documentation from the agency showing its compliance with Section 7(a)(2)of the ESA. Please see the MT-2 instructions for more detail. Not inclusive of all applicable regulatory requirements. For details,see 44 CFR parts 60 and 65. 33 FEMA Form 086-0-27A,(2/2011) Previously FEMA Form 81-89 MT-2 Form 2 Page 3 of 3 DEPARTMENT OF HOMELAND SECURITY FEDERAL EMERGENCY MANAGEMENT AGENCY RIVERINE STRUCTURES FORM O.M.B.Feb 1 PAPERWORK BURDEN DISCLOSURE NOTICE Expires Februaary ry 28 28,2 2014 Public reporting burden for this form is estimated to average 7 hours per response.The burden estimate includes the time for reviewing searching existing data sources,gathering and maintaining the needed data,and completing, You are not required to respond to this collection of information unless a valid OMB control number appears g Send comments regarding the accuracy of the burden estimate and any suggestions for reducing this burden to:n Information Collections form. Management,Department of Homeland Security,Federal Emergency Management Agency, 1800 South Bell Street,et Arlingtton,VA 20598-3 form. Paperwork Reduction Project(1660-0016).Submission of the form is required to obtain or retain benefits under the National Flood Insurance Program.Please do not send your completed survey to the above address. 20598-3005, PRIVACY ACT STATEMENT AUTHORITY:The National Flood Insurance Act of 1968,Public Law 90-448,as amended by the Flood Disaster Protection Act of 1973,Public Law 93-234. PRINCIPAL PURPOSE(S):This information is being collected for the purpose of determining an applicant's eligibility to request changes to National Flood Insurance Program(NFIP)Flood Insurance Rate Maps(FIRM). ROUTINE USE(S):The information on this form may be disclosed as generally amended.This includes using this information as necessary and authorized by the routine uses published in DHS/FEMA/NFIP/LOMA-1 National Flood Insurance Program;Letter of Map Amendment(LOMA)February 15,2006,71 FR 7990. §552a(b)of the Privacy Act of 1974,as DISCLOSURE:The disclosure of information on this form is voluntary;however,failure to provide the information requested may delay or prevent FEMA from processing a determination regarding a requested change to a NFIP Flood Insurance Rate Maps(FIRM). Flooding Source: Jackson Overbank Note:Fill out one form for each flooding source studied. Complete the appropriate section(s)for each Structure listed below: Channelization complete Section B Bridge/Culvert complete Section C Dam complete Section D Levee/Floodwall complete Section E Sediment Transport complete Section F(if required) Description Of Modeled Structure 1. Name of Structure: Twin Creeks Flood Channel Type (check one): Channelization ❑Bridge/Culvert ❑Levee/Floodwall Location of Structure: Easternmost edge of development ❑Dam Downstream Limit/Cross Section: RS 0.28 Upstream Limit/Cross Section:FILM= 2. Name of Structure: Twin Creeks Crossing Culvert Type (check one): ❑Channelization ®Bridge/Culvert ❑Levee/Floodwall Location of Structure: Crosses flood channel a..rox.3400 feet u/s of confluence with Jackson Creek mainstem Dam Downstream Limit/Cross Section: RS 2927.39 Upstream Limit/Cross Section: 3048.78 3. Name of Structure: Type (check one) ❑Channelization ❑Bridge/Culvert ❑Levee/Floodwall ❑Dam Location of Structure: Downstream Limit/Cross Section: Upstream Limit/Cross Section: NOTE:FOR MORE STRUCTURES,ATTACH ADDITIONAL PAGES AS NEEDED. FEMA Form 086-0-278,(2/2011) Previously FEMA Form 81-898 MT-2 Form 3 Page 1 of 11 34 B. CHANNELIZATION Flooding Source: Jackson Overbank Name of Structure: Twin Creeks Flood Channel 1. Hydraulic Considerations The channel was designed to carry approx1220(cfs)and/or the 100-year flood. The design elevation in the channel is based on(check one): Subcritical flow ❑ Critical flow ❑ Supercritical flow ❑ Energy grade line If there is the potential for a hydraulic jump at the following locations,check all that apply and attach an explanation of how the hydraulic jump is controlled without affecting the stability of the channel. ❑ Inlet to channel ❑ Outlet of channel ❑ At Drop Structures ❑ At Transitions ❑ Other locations(specify): 2. Channel Design Plans Attach the plans of the channelization certified by a registered professional engineer,as described in the instructions. 3. Accessory Structures The channelization includes(check one): ❑ Levees[Attach Section E(Levee/Floodwall)] ❑ Drop structures ❑ Superelevated sections ❑ Transitions in cross sectional geometry ❑ Debris basin/detention basin (Attach Section D(Dam/Basin)] ❑ Energy dissipator ❑ Weir ❑ Other(Describe): 4. Sediment Transport Considerations Are the hydraulics of the channel affected by sediment transport? ❑Yes ®No If yes,then fill out Section F(Sediment Transport)of Form 3. If No,then attach your explanation for why sediment transport was not considered. C. BRIDGE/CULVERT Flooding Source: Jackson Overbank Name of Structure: Twin Creeks Crossing Culvert 1. This revision reflects(check one): ® Bridge/culvert not modeled in the FIS ❑ Modified bridge/culvert previously modeled in the FIS ❑ Revised analysis of bridge/culvert previously modeled in the FIS 2. Hydraulic model used to analyze the structure(e.g.,HEC-2 with special bridge routine,WSPRO,HY8):HEC-RAS 4.1.0 If different than hydraulic analysis for the flooding source,justify why the hydraulic analysis used for the flooding source could not analyze the structures. Attach justification. 3. Attach plans of the structures certified by a registered professional engineer. The plan detail and information should include the following (check the information that has been provided): ® Dimensions(height,width,span,radius,length) ❑ Distances Between Cross Sections ® Shape(culverts only) ® Erosion Protection ® Material ® Low Chord Elevations—Upstream and Downstream ❑ Beveling or Rounding ® Top of Road Elevations—Upstream and Downstream ❑ Wing Wall Angle ® Structure Invert Elevations—Upstream and Downstream ❑ Skew Angle ® Stream Invert Elevations—Upstream and Downstream ❑ Cross-Section Locations 4. Sediment Transport Considerations Are the hydraulics of the structure affected by sediment transport? ❑Yes ®No If Yes,then fill out Section F Sediment Transport of Form 3. If no,then attach an ex.lanation. FEMA Form 086-O-27B,(2/2011) Previously FEMA Form 81490 MT-2 Form 3 Page 2 of 11 35 D. DAM/BASIN Flooding Source: Name of Structure: 1. This request is for(check one): ❑Existing dam/basin ❑New dam/basin 2. The dam/basin was designed by(check one):❑Federal agency 0 agency ❑Modification of existing dam/basin 9 gency ❑Private organization 0 Local government agency Name of the agency or organization: 3. The Dam was permitted as(check one): ❑Federal Dam ❑State Dam Provide the permit or identification number(ID)for the dam and the appropriate permitting agency or organization Permit or ID number Permitting Agency or Organization a. ❑Local Government Dam ❑Private Dam Provided related drawings,specification and supporting design information. '4. Does the project involve revised hydrology? ❑Yes ❑No If Yes,complete the Riverine Hydrology&Hydraulics Form(Form 2). Was the dam/basin designed using critical duration storm?(must account for the maximum volume of runoff) ❑ Yes,provide supporting documentation with your completed Form 2. ❑ No,provide a written explanation and justification for not using the critical duration storm. 5. Does the submittal include debris/sediment yield analysis? ❑Yes ❑No If Yes,then fill out Section F(Sediment Transport). If No,then attach your explanation for why debris/sediment analysis was not considered? 6. Does the Base Flood Elevation behind the dam/basin or downstream of the dam/basin change? ❑Yes ❑No If Yes, complete the Riverine Hydrology&Hydraulics Form(Form 2)and complete the table below. Stillwater Elevation Behind the Dam/Basin FREQUENCY(%annual chance) FIS REVISED 10-year(10%) 50-year(2%) 100-year(1%) 500-year(0.2%) Normal Pool Elevation 7. Please attach a copy of the formal Operation and Maintenance Plan E. LEVEE/FLOODWALL FEMA Form 086-0-27B,(2/2011) Previously FEMA Form 81-898 MT-2 Form 3 Page 3 of 11 36 1. System Elements a. This Levee!Floodwall analysis is based on(check one): upgrading of a newly reanalysis of ❑ an existing ❑ constructed an existing levee/floodwall levee/floodwall ❑ levee/floodwall system system system b. Levee elements and locations are(check one): ❑ earthen embankment,dike,berm,etc. Station to ❑ structural floodwall Station to ❑ Other(describe): Station to c. Structural Type(check one): ❑ monolithic cast-in place reinforced concrete ❑ reinforced concrete masonry block ❑ sheet piling ❑Other(describe): d. Has this levee/floodwall system been certified by a Federal agency to provide protection from the base flood? ❑Yes ❑ No If Yes,by which a en ? FEMA Form 086-0.278,(2/2011) Previously FEMA Form 81-89B MT-2 Form 3 Page 4 of 11 37 e. Attach certified drawings containing the following information(indicate drawing sheet numbers): 1. Plan of the levee embankment and floodwall structures. 2. A profile of the levee/floodwall system showing the Base Flood Elevation(BFE), Sheet Numbers: levee and/or wall crest and foundation,and closure locations for the total levee system. 3. A profile of the BFE,closure opening outlet and inlet invert elevations,type and size Sheet Numbers: of opening,and kind of closure. Sheet Numbers: 4. A layout detail for the embankment protection measures. 5. Location,layout,and size and shape of the levee embankment features,foundation treatment, Sheet Numbers: Floodwall structure,closure structures,and pump stations. Sheet Numbers: 2. Freeboard a. The minimum freeboard provided above the BFE is: Riverine 3.0 feet or more at the downstream end and throughout ❑Yes ❑No 3.5 feet or more at the upstream end ❑Yes ❑No 4.0 feet within 100 feet upstream of all structures and/or constrictions ❑Yes ❑No Coastal 1.0 foot above the height of the one percent wave associated with the 1%-annual-chance stillwater surge elevation or maximum wave runup(whichever is greater). ❑Yes ❑No 2.0 feet above the 1%-annual-chance stillwater surge elevation ❑Yes ❑No Please note,occasionally exceptions are made to the minimum freeboard requirement. If an exception is requested,attach documentation addressing Paragraph 65.10(b)(1)(ii)of the NFIP Regulations. If No is answered to any of the above,please attach an explanation. b. Is there an indication from historical records that ice-jamming can affect the BFE? ❑Yes ❑No If Yes,provide ice-jam analysis profile and evidence that the minimum freeboard discussed above still exists. 3. Closures a. Openings through the levee system(check one): ❑exists ❑does not exist If opening exists,list all closures: Channel Station Left or Right Bank Opening Type Highest Elevation for Type of Closure Device Openingjnvert (Extend table on an added sheet as needed and reference) Note: Geotechnical and geologic data In addition to the required detailed analysis reports,data obtained during field and laboratory investigations and used in the design analysis for the following system features should be submitted in a tabulated summary form. (Reference U.S.Army Corps of Engineers[USACE]EM-1110-2-1906 Form 2086.) FEMA Form 086.0-27B,(2/2011) Previously FEMA Form 81-89B MT-2 Form 3 Page 5 of 11 38 4. Embankment Protection a. The maximum levee slope land side is: b. The maximum levee slope flood side is: c. The range of velocities along the levee during the base flood is: (min.) to (max.) d. Embankment material is protected by(describe what kind): e. Riprap Design Parameters(check one): ❑ Velocity ❑ Tractive stress Attach references Flow Curve or Stone Riprap Reach SI eslope Depth Velocity Straight Depth of Toedown D,00 D50 Thickness Sta to Sta to Sta to Sta to Sta to Sta to (Extend table on an added sheet as needed and reference each entry) f. Is a bedding/filter analysis and design attached? ❑ Yes ❑ No g. Describe the analysis used for other kinds of protection used(include copies of the design analysis): Attach engineering analysis to support construction plans. 5. Embankment And Foundation Stability a. Identify locations and describe the basis for selection of critical location for analysis: ❑ Overall height: Sta.: ,height ft. ❑ Limiting foundation soil strength: Strength = degrees,c= psf Slope: SS= (h)to (v) (Repeat as needed on an added sheet for additional locations) b. Specify the embankment stability analysis methodology used(e.g.,circular arc,sliding block,infinite slope,etc.): c. Summary of stability analysis results: FEMA Form 086-0-27B,(2/2011) Previously FEMA Form 81-89B MT-2 Form 3 Page 6 of 11 9 E. LEVEE/FLOODWALL(CONTINUED) 5. Embankment And Foundation Stability(continued) Case Loading Conditions - Critical Safety Factor End of construction II Sudden drawdown III Critical flood stage 1.0 IV Steady seepage at flood stage - VI Earthquake(Case I) (Reference: USACE EM-1110-2-1913 Table 6-1) 1.0 d. Was a seepage analysis for the embankment performed? ❑Yes ❑No If Yes,describe methodology used: e. Was a seepage analysis for the foundation performed? ❑Yes ❑No f. Were uplift pressures at the embankment landside toe checked? ❑Yes ❑No g. Were seepage exit gradients checked for piping potential? ❑Yes ❑ No h. The duration of the base flood hydrograph against the embankment is hours. Attach engineering analysis to support construction plans. 6. Floodwall And Foundation Stability a. Describe analysis submittal based on Code(check one): ❑ UBC 1988 ( ) ❑ Other(specify): b. Stability analysis submitted provides for: ❑ Overturning 0 Sliding If not explain: c. Loading included in the analyses were: ❑ Lateral earth @ PA= psi; Pp= psf ❑ Surcharge-Slope @ , ❑ surface psf ❑ Wind @ Pw= psf ❑ Seepage(Uplift); ❑ Earthquake @ P„= %g ❑ 1%-annual-chance significant wave height: ft. ❑1%-annual-chance significant wave period: sec. d. Summary of Stability Analysis Results: Factors of Safety. Itemize for each range in site layout dimension and loading condition limitation for each respective reach. Criteria(Min) Sta Loading Condition To To Overturn Sliding Overturn Sliding Overturn Sliding Dead&Wind 1.5 1.5 Dead&Soil 1.5 1.5 MEM Dead,Soil,Flood,& 1.5 1.5 Impact Dead,Soil,&Seismic 1.3 1.3 -_■--, FEMA Form 086-0-27B,(2/2011) Previously FEMA Form 81498 MT-2 Form 3 Page 7 of 11 40 (Ref: FEMA 114 Sept 1986;USAGE EM 1110-2-2502) Note:(Extend table on an added sheet as needed and reference) E. LEVEE/FLOODWALL(CONTINUED) 6. Floodwall And Foundation Stability(continued) e. Foundation bearing strength for each soil type: Bearing Pressure Sustained Load(psf) Short Term Load(psf) Computed design maximum Maximum allowable FEMA Form 086-0-27B,(2/2011) Previously FEMA Form 81-888 MT-2 Form 3 Page 8 of 11 41 f. Foundation scour protection❑is,❑is not provided. If provided,attach explanation and supporting documentation: Attach engineering analysis to support construction plans. 7. Settlement a. Has anticipated potential settlement been determined and incorporated into the specified construction elevations to maintain the established freeboard margin? ❑Yes ❑No b. The computed range of settlement is ft.to ft. c. Settlement of the levee crest is determined to be primarily from ❑ Other(Describe):0 consolidation ❑ Embankment compression d. Differential settlement of floodwalls ❑ has ❑ has not been accommodated in the structural design and construction. Attach engineering analysis to support construction plans. 8. Interior Drainage a. Specify size of each interior watershed: Draining to pressure conduit: acres Draining to ponding area: acres b. Relationships Established Ponding elevation vs.storage ❑Yes ❑No Ponding elevation vs.gravity flow ❑Yes ❑No Differential head vs.gravity flow ❑Yes ❑No c. The river flow duration curve is enclosed: ❑Yes ❑No d. Specify the discharge capacity of the head pressure conduit: cfs e. Which flooding conditions were analyzed? • Gravity flow(Interior Watershed) ❑Yes ❑No • Common storm(River Watershed) ❑Yes ❑No • Historical ponding probability ❑Yes ❑No • Coastal wave overtopping ❑Yes ❑No If No for any of the above,attach explanation. e. Interior drainage has been analyzed based on joint probability of interior and exterior flooding and the capacities of pumping and outlet facilities to provide the established level of flood protection. ❑Yes ❑No If No,attach explanation. g. The rate of seepage through the levee system for the base flood is cfs h. The length of levee system used to drive this seepage rate in item g: ft. E. LEVEE/FLOODWALL(CONTINUED) 8. Interior Drainage(continued) i. Will pumping plants be used for interior drainage? ❑Yes ❑No If Yes,include the number of pumping plants: For each pumping plant,list: FEMA Form 086-0-27B,(2/2011) Previously FEMA Form 81-89B MT-2 Form 3 Page 9 of 11 42 Plant#1 Plant#2 The number of pumps The ponding storage capacity The maximum pumping rate The maximum pumping head The pumping starting elevation The pumping stopping elevation Is the discharge facility protected? Is there a flood warning plan? How much time is available between warning and flooding? Will the operation be automatic? ❑Yes ❑No If the pumps are electric,are there backup power sources? ❑Yes ❑No (Reference: USACE EM-1110-2-3101,3102,3103,3104,and 3105) Include a copy of supporting documentation of data and analysis. Provide a map showing the flooded area and maximum ponding elevations for all interior watersheds that result in flooding. 9. Other Design Criteria. a. The following items have been addressed as stated: Liquefaction ❑is ❑is not a problem • Hydrocompaction ❑is ❑is not a problem Heave differential movement due to soils of high shrink/swell ❑is ❑is not a problem b. For each of these problems,state the basic facts and corrective action taken: Attach supporting documentation c. If the levee/floodwall is new or enlarged,will the structure adversely impact flood levels and/or flow velocities floodside of the structure? ❑Yes ❑No Attach supporting documentation d. Sediment Transport Considerations: Was sediment transport considered? ❑Yes ❑No If Yes,then fill out Section F(Sediment Transport). If No,then attach your explanation for why sediment transport was not considered. 10. Operational Plan And Criteria a. Are the planned/installed works in full compliance with Part 65.10 of the NFIP Regulations? ❑Yes ❑No b. Does the operation plan incorporate all the provisions for closure devices as required in Paragraph 65.10(c)(1)of the NFIP regulations? ❑Yes ❑No c. Does the operation plan incorporate all the provisions for interior drainage as required in Paragraph 65.10(c)(2)of the NFIP regulations? ❑Yes ❑No If the answer is No to any of the above,please attach supporting documentation. E. LEVEEIFLOODWALL(CONTINUED) FEMA Form 088-0-276,(2/2011) Previously FEMA Form 81-89B MT-2 Form 3 Page 10 of 11 43 11. Maintenance Plan Please attach a copy of the fomal maintenance plan for the levee/floodwall 12. Operations and Maintenance Plan Please attach a copy of the formal Operations and Maintenance Plan for the levee/floodwall. CERTIFICATION OF THE LEVEE DOCUMENTION This certification is to be signed and sealed by a licensed registered professional engineer authorized by law to certify elevation information data hydrologic and hydraulic analysis,and any other supporting information as per NFIP regulations paragraph 65.10(e)and as described in the MT-2 Forms Instructions. All documents submitted in support of this request are correct to the best of my knowledge. I understand that any false statement may be punishable by fine or imprisonment under Title 18 of the United States Code,Section 1001. Certifier's Name: License No.: Expiration Date: Company Name: Telephone No.: Fax No.: Signature: Date: E-Mail Address: F. SEDIMENT TRANSPORT Flooding Source: Name of Structure: If there is any indication from historical records that sediment transport(including scour and deposition)can affect the Base Flood Elevation(BFE); and/or based on the stream morphology,vegetative cover,development of the watershed and bank conditions,there is a potential for debris and sediment transport(including scour and deposition)to affect the BFEs,then provide the following information along with the supporting documentation: Sediment load associated with the base flood discharge: Volume acre-feet Debris load associated with the base flood discharge: Volume acre-feet Sediment transport rate (percent concentration by volume) Method used to estimate sediment transport: Most sediment transport formulas are intended for a range of hydraulic conditions and sediment sizes;attach a detailed explanation for using the selected method. Method used to estimate scour and/or deposition: Method used to revise hydraulic or hydrologic analysis(model)to account for sediment transport: Please note that bulked flows are used to evaluate the performance of a structure during the base flood;however,FEMA does not map BFEs based on bulked flows. If a sediment analysis has not been performed,an explanation as to why sediment transport(including scour and deposition)will not affect the BFEs or structures must be provided. FEMA Form 086-0-27B,(2/2011) Previously FEMA Form 81-898 MT-2 Form 3 Page 11 of 11 44�g {Date} {Affected property owner name) {Affected property owner mailing address) Re: Notification of Floodway Revision for Jackson Overbank Dear Mr./Ms./Mr. &Mrs. {Affected property owner) The Flood Insurance Rate Map (FIRM) for a community depicts the floodplain, the area which has been determined to be subject to a 1% (100-year) or greater chance of flooding in any given year. The floodway is the portion of the floodplain that includes the channel of a river or other watercourse and the adjacent land area that must be reserved in order to discharge the base flood without cumulatively increasing the water-surface elevation by more than a designated height. The City of Central {insert appropriate community department for floodplain management), in accordance with National Flood Insurance Program regulation 65.7(b)(1), hereby gives notice of the Twin Creeks Development Co., LLC's intent to revise the floodway, along the Jackson Overbank Reach located between Griffin and Jackson Creeks, west of Highway 99. Specifically, the floodway shall be revised from a point upstream of the confluence with Jackson Creek to the confluence with Griffin Creek near the crossing with Highway 99. As a result of the floodway revision, the floodway shall uniformly be narrowed by a maximum of approximately 380 feet. In addition, the 1% annual chance water-surface elevations and the 1% annual chance floodplain shall be revised along the Jackson Overbank Reach. As a result of the revision, the 1% annual chance water-surface elevations shall decrease and the 1% annual chance floodplain shall narrow within the area of revision. Maps and detailed analysis of the floodway revision can be reviewed at the {insert location} at {insert location address). If you have any questions or concerns about the proposed project or its affect on your property, you may contact {name of appropriate community official} of {name of community} at {community official contact information} from ... to ... {insert dates during which community contact person can be contacted). Sincerely, {Community official name) {Community official position} {Community official contact information} 46 The City of Central {insert appropriate community department for floodplain management}, in accordance with National Flood Insurance Program regulation 65.7(b)(1), hereby gives notice of the Twin Creeks Development Co., LLC's intent to revise the floodway, along the Jackson Overbank Reach located between Griffin and Jackson Creeks, west of Highway 99. Specifically, the floodway shall be revised from a point upstream of the confluence with Jackson Creek to the confluence with Griffin Creek near the crossing with Highway 99. As a result of the floodway revision, the floodway shall uniformly be narrowed by a maximum of approximately 380 feet. In addition, the 1% annual chance water-surface elevations and the 1% annual chance floodplain shall be revised along the Jackson Overbank Reach. As a result of the revision, the 1% annual chance water-surface elevations shall decrease and the 1% annual chance floodplain shall narrow within the area of revision. Maps and detailed analysis of the revision can be reviewed at the {insert location} at {insert location address). Interested persons may call {insert community contact name or position} at {insert contact phone number) for additional information from ... to ... {insert dates during which community contact person can be contacted). � f ;;_ .� ,.`_ L, '1, ../. . .. T. ,I . k.'F (J. ,. 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T ! i gqi El'tgn N. . 1 E i Wii 111 i cciwl nth Z Gji 0 1 I r'.. ,._ I ----'-- 7 k.),1;1 [42, . 4..i co 0 Pi 1 I / 7/ \' 5 •I Z i U WI CC I 0 1 •• s- .....I I> P "1 Is - - - ' Z.T. 1 "4 , .....,-* _ •=it-7,' It -, i - API.1 01'41 w t 1 •17^;,:,,-,:"-f- 0)01 14 /ii 01 hitkccip 0, Luiz n iil r 11 0N-04.ii ....—MM.Nliill10 tt lit 0.: ; 0 Elz" ) CC . --`- „,fx r . • I.= r:Iii i 7. , - . .:... E ;c-• / It ......., /\ ,, hi . I I-. 2 161 g - ' 05 tli 11 --I Ci 71:61 i i ill z ,,g 11 1111 Pi 11 glii I ! 4 ip 141 0 ..., i ili tl g i ! 52 ol c A ATTACHMENT ".C..". C N L Twin Creeks Floodway Mitigation Project � sect fa . \ A :„ ,. i 9 Tik #A t la. VA v., 7,.. ,... c.,/..) . .,..„ ,,, .., ofr N. • • :.. 4 %� 40 Or 0 1 295 e 590 I # # 1180 Feet t 1 Legend source informatics: rp_st*eams FE1.14 Flood Insurance Rate Map Map No 410290 Panel tic,. 1768F t,,'%% Re.sset iocd�:ay—re'r2C! i Eife �et.f3; 3, 2011 Ree sed Zcne.AE_re 2C f s NorthNest Hy 'aulic C3n:3Jitar#s,Inc. Re..sei_Zone.=,H_re•42C, Pr,p;sedFloo s'3. and Zen?:=.E re.isicr 20 Si crt s 14. Tax Lots O'eated%y: Stephanie Holey. OFM Efle.zr,eZcne.=,E 53 Jul: 28.2014 E`rea`re Ficcdvay ATTACHMENT "E PLANNING COMMISSION RESOLUTION NO. 806 A RESOLUTION OF THE PLANNING COMMISSION APPROVING A FLOODPLAIN DEVELOPMENT PERMIT FOR THE TWIN CREEKS FLOODWAY MITIGATION PROJECT (File No: FP 14001) WHEREAS, the applicant has submitted a floodplain development application to conduct grading and channel protection activities on property identified on the Jackson County Assessor's map as 37 2W 03CA, Tax Lots 900 and 1600; 37 2W 03DB Tax Lot 900; 27 2W 03BD Tax Lot 4200; 37 2W 03BC Tax Lot 100; 37 2W 03B,Tax Lots 1602 and 1800 in Central Point, OR 97502. WHEREAS,the project site is located in the TOD-OS, Open Space zoning district; and WHEREAS,the application has been found to be consistent with the applicable approval criteria set forth in Chapter 8.24, flood damage prevention standards for floodway development and per conditions noted in the Staff Report dated August 5, 2014; and WHEREAS, on August 5, 2014, at a duly noticed public hearing, the City of Central Point Planning Commission considered the Applicant's request for floodplain development approval for Twin Creeks Floodway Mitigation Project. NOW, THEREFORE,BE IT RESOLVED that the City of Central Point Planning Commission by Resolution No. 806 hereby approves the Twin Creeks Floodway Mitigation Project based on the findings and conditions of approval as set forth in Exhibit "D," the Planning Department Staff Report dated August 5, 2014, including attachments incorporated by reference. PASSED by the Planning Commission and signed by me in authentication of its passage this 5th day of August, 2014 Planning Commission Chair ATTEST: City Representative Planning Commission Resolution No. 806 (08/05/14) y 5 4