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HomeMy WebLinkAbout024925 - Construction-Related - Contract - Halff AssociatesHE Halff Associates ENGINEERS • ARCHITECTS • SCIENTISTS PLANNERS• SURVEYORS April 1, 1999 AVO 1008-98-9811 Mr. Doug Rademaker, P.E. City of Fort Worth 1000 Throckmorton Fort Worth, Texas 76102 8616 NORTHWEST PLAZA DRIVE DALLAS, TEXAS 75225 (214) 346-6200 FAX (214) 739-0095 CITY SECRETARY /,, CONTRACT NO. 1 Re: Wetland Mitigation Evaluation, Section 404 Wetland Permit and Landscape Mitigation Plans for Wayside Avenue Drainage Channel, City of Fort Worth, Project 199800004 Dear Mr. Rademaker: Halff Associates is pleased to submit this proposal for the evaluation of alternative wetland mitigation sites and preparation of mitigation landscape plans for the Wayside Avenue Drainage Channel. The services we propose to provide are described herein. Scope of Work Based on the Section 404 Permit meeting held at the Corps of Engineers office, we are pleased to present our proposal to assist the City of Fort Worth in obtaining a Nationwide Permit No. 26 for the Wayside Channel project. Our understanding of the requested information from the Corps is described in the following tasks: I. Description of pre-existing conditions of the channel prior to the "current" construction. This will be documented from City photographs and cross sections of pre -construction conditions. II. A description of what has been done from the former construction contractor and what needs to be done to complete the proposed project. III. A mitigation plan needs to be prepared which will describe proposed tree plantings along the Wayside Channel project and the restoration or enhancement of another similarly sized stream segment in the Sycamore Creek watershed. The additional mitigation needs to occur on public property and could include some of the following activities: A. habitat restoration in the form of tree plantings along a stream to create a new riparian corridor; B. re-establish stream meanders or riffle/pool complexes in a previously channelized stream segment; and C. correct erosion problems, thereby stabilizing a water quality deterrent. The mitigation plan must satisfy the Corps' evaluation of providing offsetting benefits from the impacts of the proposed project. The development of the mitigation plan will require coordination with City Staff of the Public Works and Park Departments to identify an appropriate mitigation area. A mitigation plan will be developed and presented to the City prior to reviewing it with the Corps. The plan will be reviewed with the Corps in the field and then modified, if required, based on the Corps' initial review. DALLAS • FORT WORTH • HOUSTON • McALLEN TRANSPORTATION • WATER RESOURCES • LAND DEVELOPMENT • MUNICIPAL • ENVIRONMENTAL • STRUCTURAL MECHANICAL • ELECTRICAL • SURVEYING • GEOGRAPHIC INFORMATION SYSTEMS ARCHITECTURE • LANDSCAPE ARCHITECTURE • PLANNING H! Halff Associates ENGINEERS • ARCHITECTS • SCIENTISTS PLANNERS •SURVEYORS Mr. Doug Rademaker, P.E. April 1, 1999 Page 2 The mitigation plan will be shown on a scaled map of the project site, and proposed planting and construction activities to be accomplished. It is assumed that the City will provide Halff Associates a digital topographic file of the project area. Subsequently, an application for a Nationwide Permit No. 26 will be prepared and submitted for Corps processing. Landscape Plans On -Site Mitigation (Wayside Avenue Channel Site) We will prepare a planting plan, illustrating the planting locations for 30 one -inch to 2 inch trees. These tree plantings will supplement the existing trees on the northern half of the channel. Details for the planting of these trees will be included on the plans. Off -Site Mitigation Emergent Herbaceous/Aquatic Wetlands We will design six to eight excavated planting areas in the channel bottom adjacent to the toe of the channel side slope, each approximately 25 feet long by ten feet wide. We will indicate planting locations for four or five Buttonbush shrubs, and for the sprigging of each area with native sedges or rushes for erosion and siltation control. Riparian Corridor Plantings We will prepare planting plans for the installation of approximately 50 five -gallon and 20 two-inch caliper trees at the Helen Meadows Park site on the north side of the creek. In addition, the plans will identify plantings for approximately 50 five gallon and 20 two-inch caliper understory trees. The plans will identify areas to be grassed with native grasses. On the south side of the creek we will prepare plans for the planting of 30 one to two-inch trees. Specifications We will prepare bid specifications for the plant materials and site improvements. These specifications will set forth minimum standards for the selection of plant materials, and the proper installation of the materials. Prepared soil backfill for the plantings will also be specified. %i Halff Associates ENGINEERS • ARCHITECTS • SCIENTISTS PLANNERS• SURVEYORS Mr. Doug Rademaker, P.E. April 1, 1999 Page 3 Specifications will identify erosion control fabric material to be used at select locations of the project and will provide general guidance for its installation. Guidance for the grading of planting areas, where applicable will be noted on the plans. Meetings We will attend up to two meetings with the City of Fort Worth during the course of this design phase of the project. Fee We will provide the services outlined above for a Lump Sum Fee of $9,823.73. Costs incurred will be carefully monitored during the progress of this project. Our services will be invoiced monthly, based on a percentage of work completed. Direct costs, including printing and reproduction, postage, messenger service, long distance telephone calls and travel outside of the Dallas/Fort Worth Metroplex will be considered reimbursable and billed at 1.10 times the direct cost incurred. The fees established above are based on obtaining an approved site plan prior to start of work. The site plan will be prepared by the Architect or Engineer. The fee established above does not include revisions once the design is underway. If revisions are requested by the Owner, a revision to the scope and budget will be required. If this proposal is satisfactory, please sign both original copies and return one to us for filing and as your notice for us to proceed with the work. If you have any questions, please do hesitate to call me or Mr. Brian Bristow at (214) 346-6267. ATCV DV Sincerely, HALF ASSOCIAT S, INC. David S. Morgan, Enviro ntal Scientist Vice President c: Mr. Brian Bristow, RLA lff Asso es, Inc. Approved by: ate: APfl0VED AS TO P0E* AND LEGALITY ANNis;dnt City Attorney Contract Authoi.ization 6 -8-99 Date w