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HomeMy WebLinkAboutWORK ORDER - RFP - 7084 CONSULTING ENGINEERING SERVICES (19)EXHIBIT "A" WORK ORDER FORM PURSUANT TO AN AGREEMENT BETWEEN THE CITY OF FORT COLLINS And Ayres Associates. 102(o3O March 26, 2012 Work Order Number: NA — 12-001 Project Title: FEMA modeling and documentation for Poudre River/McMuny Commencement Date: April 1, 2012 Completion Date: November 30, 2012 Interim milestones to meet project needs as listed below: Interim milestones: 1. King Surveyorsbegin survey within 2 weeks after Notice to Proceed. 2. King complete survey no later than 4/27/2012 3. Ayres begin modeling effort no later than 5/14/2012 4. Ayres submit package to Larimer County and City of Fort Collins no later than 9/14/2012 S. Flood Review Board hearing in October 2012 6. Package submitted to FEMA in mid -November 2012 Maximum Fee: Not to exceed $80,652 Project Description: See attached description Scope of Services: See attached Scope of Services service Provider agrees to perform the services idenaned above The attached forms consisting of zero (0) pages are end on the attached farms in accordance with the terms and hereby accepted and incorporated herein by this conditions contained herein and In the Services Agreement between the parties. in the event of a conflict between or reference, and Notice to Proceed is hereby given. ambiguity in the terms of the services Agmenrenl and this work ordcrtincluding the atloched rarnul, the se'lew Agmnacni shall central. Service Provider By: Date: APPROVAL: 4t,143 City of Fort Collins n" Collins �t By: "�,r•/P Dpp ra-k jBate: c,,.s� 2 /r 2 d / 2— -10SzO-7. SZ12I b 3/13/2012 Scope of Work for Page I of 6 FEMA Modeling and Documentation for Poudre River/McMurry Project EXHIBIT:A SCOPE OF WORK . FOR FEMA MODELING AND DOCUMENTATION FOR POUDRE RIVER/MCMURRY PROJECT. PURPOSE The purposc of this work -is to. develop hydraulic modeling: and documentation for the Poudre River improvements as part of Phase 2 of the McMurry Natural Area. TASK I -PROJECT COORDINATION AND ADMINISTRATION This task.allows for coordination with City staff:and other project team members; along with preparation of monthly. progress -reports and invoices. It also allows for coordination with external stakeholders; including FEMA/Michael Baker (specifically regarding the timing and coordination of the CLOMR submittals for the McMu ry project and the Shields Street bridge project) and the West Vine Outfall project team (specifically regarding the location and design of the West Vine outfall into the Poudre River). TASK 2-.DATA COLLECTION 2.1 Topographic/bathymetric survey (by King Surveyors). King surveyors will perform fieldsurveying of channel cross sections at specific locations and topography of the Phase I area recently re -graded by the City;'as indicated in the attached.figure. The Phase 1 area topography will be of sufficient detail and quality to provide 2-foot elevation contours. King Surveyors will provide cross section data and a surface digital terrain model of the subject river reach and Phase I area. King surveyors will also spot- check the City's 1999 2-ft contour topography at.10 locations. 2.2 Field reconnaissance. Ayres engineers will perform a site reconnaissance visit. Ayres will observe, photograph and document hydraulic aspects of the site, including the items listed below. • Roughness characteristics of the channel bed, lower bank, upper bank and overbank areas of each cross section • : Validity of topographic mapping based on visual observation • General heights of bank segments at various locations • Hydraulic controls or structures in the channel or overbanks that could affect large-scale flow patterns or energy losses- 3/13/2012 Scope.of Work for Page 2 of 6 FEMA Modeling and Documentation for Poudre River/McMurry Project Ayres will prepare a package of field notes, photographs and captions for inclusion in the Floodplain Modeling Report (see Section 7). Field reconnaissance for the sediment impact analysis, to be conducted by a senior geomorphologist, is itemized under Task 8. 2.3 Other relevant data.: Ayres will gather and examine other relevant data, including utility locations; the LOMR-Fill information' for the Bender Mobile Home Park; and photos and repair information for the right bank scour in April 1999. TASK 3- DUPLICATE EFFECTIVE (DE) MODELS 3.1 Verify study reach. The potential study reach is from a downstream limit roughly 0.6 river miles downstream of Shields Street (at the location of Cross Section Cl on FEMA FIRM Panel 977) to an upstream limit just upstream of the Josh Ames diversion structure, roughly 0.3 miles upstream of Shields Street. Any impact from the McMurry project should be small and should be expected to propagate no further than the . downstream face of the Shields Street Bridge. It is possible, -however, that the impact from the project could propagate as far as the Josh Ames structure.. Project work in the flood fringe, for example, could be allowed to cause flood:profrle changes of as much as 0.5 feet at, the project.site, with the effect carrying.upstream to the Josh Ames structure. The modeling scope for the McMutry project is complicated. by fact that Ayres will be conducting modeling of roughly the same river reach for the Shields Street Bridge replacement project. The fee proposal for the McMurry project incorporates the full model reach from Cross Section Cl to the Josh Ames structure. It assumes, however, that the physical changes incorporated in the Corrected Effective, Existing Conditions and Proposed Conditions modeling effort for.the.McMurry project will be limited strictly to the cross sections downstream of Shields Street. Any.physical changes to cross sections upstream of Shields Street will be handled as part of the Shields Street Bridge project. Under this subtask Ayres will verify the study.reach and will compile and extract the relevant segments of the current FEMA effective models. The FEMA-recognized effective models for the reach include two HEC-2 models in the downstream portion (one of which is a separate model depicting the 0.5-foot surcharge floodway) and a HEC-RAS model in the upstream portion. This scope of work assumes that the City will provide the effective HEC-2 models.to Ayres. 3.2 Develop Duplicate Effective (DE):REC-RAS.model of studyreach:.Ayres will develop a HEC-RAS model comprised of.the relevant portions of the effective HEC-RAS model and imported_data, from the.relevantportion of:the effective HEC-2 model. Discharge rates will be assigned to individual cross sections or groups of cross sections to match the effective HEC-RAS and HEC-2 models.:This scope of work excludes any new hydrologic analysis by Ayres for the DE models or, any models in the study. 3/13/2012 Scope of Work for Page 3 of 6 FEMA Modeling and Documentation for Poudre River/McMurry Project 3.3 Run DE models and process: results. Ayres will run and troubleshoot the DE models for the 10-, 50-, 100-, and 500-year floods and the effective 100-year, half -foot surcharge floodway. Ayres will prepare tables comparing the results of the DE model to the FEMA-recognized effective flood profiles.. TASK 4- CORRECTED EFFECTIVE (CE) MODELS 4.1 Add cross section locations. Ayres will add new cross section locations as will be needed to properly assess the impacts of the project. 4.2 Modify geometry data. Ayres will modify the cross section geometry to reflect the new survey.data within the main channel and overbank topography as represented by the City's 1999 2-foot contour topography (assuming spot-checking of Task validates the 1999 topography). Ayres will add ineffective. flow areas and/or blocked obstructions as necessary to accurately reflect the flow patterns at the cross section. 4.3 Correct apparent errors. Ayres will follow FEMA protocol in correcting any errors that are apparent in the DE model. Such corrections could include, but are not limited to: Manning n values,ineffective flow, incorrect reach lengths, etc. 4.4 Run CE models and:process results. Ayres will run and troubleshoot the CE models for the 10-, 50-, 100-, and 500-year floods and the effective 100-year, half -foot surcharge floodway. The discharge rates in the CE models will match those.in the DE models, with propagation or interpolation as appropriate to cross sections in -the CE models that are not included in the DE models. Ayres will prepare tables comparing the results of the CE model to the DE results. TASK 5- EXISTING CONDITION (EC) MODELS 5.1 Modify geometry input to reflect existing conditions. Ayres will modify the cross- section geometry to reflect significant recent physical changes to the floodplain. Specifically the recent re -grading of the.McMurry.Phase I area, the Bender Mobile Home Park LOMR-Fill, and the April 1999 bank erosion and repair will be incorporated, along with the updated overbank topography in the vicinity of Shields Street recently surveyed by King Surveyors in connection with the Shields: Street Bridge replacement. project. 5.2,Run EC models and.process results. Ayres will run and troubleshoot the EC models for the 10-; 50-, 100-, and 500-year.floods and the effective 100-year, half -foot surcharge floodway. The discharge rates in the EC. models will be the same as those in the CE models. Ayres will prepare tables comparing the results of the EC model to the CE results. 3/13/2012 Scope of Work for Page 4 of 6 FEMA Modeling and Documentation for Poudre River/MeMurry Project TASK 6- PROPOSED CONDITION (PC) MODELS 6.1 Modify geometry data to reflect proposed conditions. Ayres will modify the model geometry to reflect the proposed physical changes associated with the Poudre River restoration project. 6.2 Run PC 100-year models and evaluate compliance with floodplain regulations. Ayres will run and troubleshoot the PC models for the 100-year flood and the effective 100-year, half -foot surcharge floodway. The discharge rates in the PC models will be the same as those in the EC models, unless the proposed design for the West Vine Outfall project will affect the discharge rates, in which case Ayres will enter modified flow rates into the PC models to reflect post -project hydrology performed by others. Ayres will compare the results of the PC models to the EC and CE models to assess compliance with regulations. Ayres will consult with the City floodplain administrators as necessary and will meet with the project team to advise on design changes that may be needed to achieve compliance. 6.3.Assess the need for floodway revisions and revise as necessary. Ayres will evaluate the suitability of the effective regulatory floodway relative to.the proposed changes associated with the project and also considering the effects of the Shields Street bridge replacement project as relevant to the McMurry project reach. If the modeling shows that the effective floodway would cause surcharges exceeding 0.5 feet at any cross section, Ayres will develop proposed revisions to the floodway as needed, and in consultation with the City floodplain administrators to keep the surcharge at or below 0.5 feet. 6.4 Run updated PC models and process results. After the design has been modified as needed, Ayres will tun and troubleshoot the updated PC models for the 10=, 507, 100-, and 500-year floods and the effective 100-year, half -foot surcharge floodway. Ayres will prepare tables comparing the results of the PC model to the EC and CE results. TASK 7—PREPARE FLOODPLAIN REPORT AND CLOMR PACKAGE 7.1 Prepare Floodplain Report. Ayres will prepare a floodplain analysis report meeting the requirements of the City's Floodplain Modeling Guidelines and Chapter 10 of the City Code. The report will include narrative explaining the analysis approach and the results. The comparison tables referenced in the task descriptions above, will be incorporated into the report, along with printouts of the HEC-RAS inputs and results. Narrative will be included to explain the probable reasons for any differences in flood profiles between the various modeling conditions. Workmaps will be prepared illustrating the effective floodplain boundaries along with the inundation from the CE, EC and PC models. The workmaps will also depict the effective floodway boundaries and any proposed changes to the floodway. 3/13/2012 Scope of Work for Page 5 of 6 FEMA Modeling and Documentation for Poudre River/MeMurry Project 7.2 Compile CLOMR application package. Ayres will compile a CLOM&package consisting of the report and workmaps described above, along with MT-2 forms, public notice letters, annotated FIRM.panels .annotated FIS.tables, updated FIS profiles, GIS files, survey documentation and other required data. 7.3 Process CLOMR package through local jurisdictions. Ayres will submit the CLONM package to the floodplain administrators at both the City of Fort Collins and Latimer County. Ayres will attend a pre -application meeting with the County and also meet with the City. floodplain administrators to discuss the project and its impacts and mitigations. Ayres wilt attend.the County Flood Review Board hearing on the CLOMR package. Once the required signatures are obtained.from Larimer County and the.City, the CLOMR package will be submitted to both FENQu Michael Baker and the Colorado Water Conservation Board. This subtask also allows for Ayres to develop appropriate responses to comments from any of the relevant stakeholders. The fee -proposal assumes Ayres will respond to two rounds of comments from local jurisdictions prior to submitting the CLOMR package and one round of FEMA/Michael Baker comments. Note that the fee proposal assumes any CLOMR or permit fees due to FEMA or other reviewing jurisdictions will be paid by the City of Fort Collins and are excluded from Ayres' contract. Also note that Endangered Species Act clearances must be obtained prior to submission of the CLOMR package, and must be included in the submittal to FEMA/Michael Baker. TASK 8-ASSESS SEDIMENT TRANSPORT IMPACTS 8.1.Geomorphic data review and field reconnaissance. A senior geomorphologist on Ayres' staff will gather and examine available data, and perform a site visit to assess and document the following: • Overall lateral and vertical stability of the main channel in the reach of interest • Identification and comparison of geomorphic subreaches, based on channel planform, slope, bank height, flow characteristics, etc. • Size distribution of cobbles on the surfaces of bars (assume 4 Wolinan counts) • Obtain samples of the sandy gravel bed material beneath the cobble surface layer (assume 4 samples) • History of stability problems that have occurred in other reaches of the Poudre River (through conversations with City staff) 8.2 Grain size distributionanalysis: The bed material samples mentioned above will be taken to a local geotechnical engineeringfirm with appropriate equipment to obtain grain size distributions. This scope of work assumes 4 samples will be analyzed. 3/13/2012 Scope of Work for Page 6 of 6 FEMA Modeling and Documentation for Poudre River/McMurry Project 8:3SIAM analysis.of.existing conditions for frequent flows. Sediment transport impacts from the project could be realized under frequent flow conditions. Ayres will use the Sediment Impact Analysis Methods function within HEC-RAS to assess the potential for such impacts. The method involves dividing the reach of interest into geomorphically similar subreaches; computing the annual sediment transport capacity of each subreach; and comparing the transport capacity in each reach to the sediment supply. If a subreach has greater transport capacity than supply, the annual sediment deficit (representing degradation potential) will be computed: If the supply is greater than the transport capacity the annual sediment surplus (representing aggradation potential) will be computed. A SIAM analysis of existing reach conditions will be performed to develop an analysis baseline for each subreach. 8.4 SIAM analysis of proposed conditions for frequent flows. Ayres will perform a SIAM analysis of proposed conditions. The results will be compared to the results from existing conditions. If the proposedconditions analysis shows a significant change in the sediment deficit or surplus values: for a subreach compared to existing:conditions, that subreach will be identified as potentially impacted. 8.5 Laursen's live -bed analysis of existing conditions. Sediment impacts from the project could also be realized under relatively short -duration flood conditions. Ayres will use Laursen's live -bed scour equation;as presented in the Fourth Edition of HEC-18, to assess the potential for. contraction scour or deposition within subreaches; under existing conditions. The existing -conditions analysis.will be consider the l0-year, 50-year and 100-year flood events. 8.6 Laursen's live -bed analysis:of proposed conditions. Ayres will perfornialive-bed scour analysis of proposed conditions. The results will be compared to the results from existing conditions. If the proposed conditions analysis shows a significant change in the potential for contraction scour or deposition in subreach compared to existing. conditions, that subreach will be identified as potentially impacted.. The proposed - conditions analysis will be consider the I O.-year, 50-year and 100-year flood events. 8.7 Recommend design modifications and update analyses. Ayres will discuss potentially impacted reaches, as.identified under.Tasks 8.4 and 8.6 above, with the design team and.provide conceptual recommendations for design changes to mitigate the impacts. Ayres will update the SIAM and Laursen's analyses as needed to. reflect design changes. 8.8 Prepare and submit technical memo. Ayres will prepare a memo summarizing the results of the Task 8 activities for inclusion, as an appendix to FloodpWn Report. . Ayres Associates • Professional Sarvlcas Fee Proposal A\R W FEMA Modeling and Documentation for Poudre River/McMurry Project ASSOCIATES Ayres Associates - Professionals Services Fee Proposal AV�L� FEMA Modeling and Documentation for Paudre River/McMurry Project ASSOCIATES Based on Scope of Services dated 3/12/2012