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DR0002-PR010531401 ! W. Piano Pkw¥, Suite 108 Piano. Texas 75093 ' Ph: (972) 312-8850 Fax: (972) 312-0675 oei] ~oeidallas.com Hydraulics/Hydrology Civil Engineering Co~sultin8 May 31,2001 Mr. Ken Griffin, P.E. , City Engineer City of Coppell 255 Parkway Blvd Coppell, Texas 75019 RE: Proposal for Engineering Services Box Culvert Extension Meadowcreek Road on Unnamed Tributary of Grapevine Creek Dear Ken: This proposal for engineering services is provided by O'Brien Engineering, Inc. (OEI) to the City of Coppell, Texas (City), concerning engineering and related services to provide plans for the extemion of an existing pipe culvert with 175 feet of a 6'x5' box culvert between two houses along the south side of the street, as called for in the City's Master Drainage Study. The City is proposing to enclose the channel downstream of the existing pipe culvert as a means of eliminating the erosion that occurs in this area. The proposed box will connect to the downstream face of the existing pipe culvert and continue for a distance of approximately 175 feet downstream. The box will pass under an existing sanitary sewer that crosses the creek in an aerial structure. The City obtained a topographic survey of the area fi.om Shimek, Jacobs and Finklea, L.L.P. (SJF) field crews approximately eight months ago. At the present time, the channel collects and conveys local runoff toward Grapevine Creek, in addition to flow fi.om the existing pipe culvert. Therefore, it will be necessary to provide for the local runoffwith area drains, an inlet and a swale. The swale would run above the proposed box culvert, generally along the alignment of the existing channel. The City wishes to abandon the existing easement in the area and obtain additional easement from the property owners to comprise a 20 feet wide easement centered on the proposed box culvert. The unnamed tributary is not a FEMA studied stream. However, as a result of backwater fi.om Grapevine Creek, the portion of the tributary downstream of Meadowcreek Road is designated as zone 'AE' on the current effective flood insurance rate map for Coppell (panel number 480170 0010E dated, April 15, 1994.) Nonetheless, this portion of the tributary, and all of the proposed box culvert, is within the floodway fi'inge. According to the City Floodplain Ordinance, fill may occur within the floodway fringe without submittal to FEMA. Furthermore, based on a review of the creek geometry, the effective FIRM and onsite observations, the proposed improvements will be in an ineffective flow Mr. Ken Griffin, P.E. 5/31/2001 Page 2 area of Grapevine Creek, resulting in no impact on the hydraulics of that creek. It is our understanding that the City will prepare the specifications and contract documents based on construction drawings and quantities to be provided by OEI. The City will also address the protection, replacement and/or repair of sprinkler systems and components. We propose the following: I. BASIC SERVICES A. Data Gathering - Obtain deed and plat records of the subject property and adjoining properties and as-built plans of local utilities from readily available public records. Obtain drainage area map and drainage plan and profile pertaining to the existing culvert. B. Demolition Plan - prepare a demolition plan to identify features that must be removed, repaired, or amended prior to construction of the box culvert. C. Drainage Area Map - using city topography as a base, delineate the contributing drainage area. Calculate the 100-year peak runoffand the hydraulic gradeline in the proposed and existing system elements. Show calculations on the map. D. Storm Sewer Plan and Profile - prepare a design plan showing the box culvert geometric layout and profile that will include calculations for the culvert hydraulics. OEI intends to utilize box culvert geometry, design and details that are included in Texas Department of Transportation standards. Copies of appropriate TXDOT sheets will be provided in the final design set. E. Cross Sections - OEI will prepare cross section sheets to provide culvert sections on a minimum 25 feet spacing along the approximate 175-foot alignment. F. Utility Plan - prepare a design plan for the protection of the aerial crossing of the existing sanitary sewer. This plan will include a plan, profile, and detail(s) for the required construction. At the present, there do not appear to be any waterline conflicts. However, the plan will also indicate any small diameter (less than 10 inch) water distribution line relocations that may be required by the proposed construction. G. Erosion Control Plan - prepare a plan showing initial erosion control measures including silt fence layout, inlet protection, and stabilized site entrance. This plan is intended for use in the Storm Water Pollution Prevention plan required to be completed by the City and selected contractor in accordance with federal law. H. Opinion of Probable Cost - determine construction quantities based on preliminary plans. Prepare an opinion of probable cost. I. Easements - Using the proposed alignment and property descriptions provided on the plat of the subdivision, OEI will prepare preliminary descriptions for use by the City to discuss with the Homeowners and the final legal descriptions for use in legal 'Mr. Ken Griffin, P.E, 5/31/2001 Page 3 recording documents prepared by the City. By field survey, locate additional plat comers along the common property line. Set iron rods at easement comers. J. Submittal - Submit plans and easement documents to City for approval. Meet with City staff for review and comments. Make necessary modifications to plans and easements. Revise construction quantities and opinion of probable cost. Resubmit. K. Construction Services - The City will supply construction administration and construction inspection. OEI will provide one-time field staking of line and grade for the proposed box culvert and grading. Based on documentation provided by contractor at completion of project, we will notate and seal the construction drawings as 'record drawings', assuming there are no significant field changes. Transmit record drawings to City. II. ADDITIONAL SERVICES If additional services, beyond those described are deemed appropriate, these services will be provided as requested by City and, if so desired, a separate proposal will be provided. Additional services may include the following: A. Representing the City at City council or staff meetings, P&Z meetings, and at homeowner meetings, other than, and beyond those identified in Basic Services. B. Preparing special surveys, plats, studies and submissions (other than those identified under basic services) required for approval by any agency having authority over the project or study area. C. FEMA submittals. D. Services associated with obtaining a US Army Corps of Engineers Section 404 permit, verification or PCN, or assistance in developing a plan of mitigation. E. Services associated with the preparation of off-site easements. F. Assistance to the City as an expert witness in any litigation with third parties. G. Services associated with preparing a Notice of Intent for submittal to EPA, development of a storm water pollution prevention plan or MS4 permit. H. Title search of the affected properties, or other services to resolve property boundary conflicts or deficiencies. I. Design, relocation or protection of any utilities other than small diameter water and the sanitary sewer line that may be required to complete construction of the box culverts. J. Construction observation to ensure that construction proceeds in general accor~ with the design plans. · Mr. Ken Griffin, P.E 5/31/2001 Page 4 K. Construction staking beyond that identified under Basic Services. L. Revising construction drawings in preparation of record drawings as a result of alignment changes, recalculation, significant additions/deletions, and the like, to the original plans. III. COMPENSATION Compensation to OEI for the above-described services shall be according to the following schedule: A. Basic Services - At our hourly rates (copy attached) for a cost not to exceed $12,700 without prior written approval. B. Additional Services - on an hourly basis as requested by the City. A copy of our hourly rates is attached. A separate proposal will be provided on any additional services item at City's request. C. In addition to compensation for specified services, OEI will be reimbursed for direct project expenses incurred during the course of the project which are requested by the City, such as blue prints, photographs, printing, travel outside the Metroplex, messenger services and the like. Billings will be on a monthly basis and payment is due 10 days after the billing date. The City may terminate this contract by written notice. Upon receipt of such notice, OEI agrees to cease all work related to the contract within 24 hours. The City agrees, in such case to compensate OEI for reasonable expenses incurred and for services completed through the time of cessation, on an hourly basis at our hourly rates (copy of the rate schedule is attached). The contract may be amended by the mutual agreement of the parties in an addendum to he attached to the contract. OEI appreciates the opportunity to submit this proposal. We are prepared to begin work immediately. The work will take approximately three weeks to complete. The terms of the contract shah be valid for a period of 12 months fi.om the date of this proposal. If the proposal meets with your approval, please sign and return one copy for our files. Sincerely, APPROVED: O'BRIEN ENGINEERING, INC. CITY OF COPPELL [./President attachment 4011 W. Piano Pkwy, Suite 108 Piano, Texas 75093 Ph: (972) 312-8850 Fax: (972) 312-O675 Hydraulics/Hydrology Civil Engineering Consulting HOURLY RATES February 2000 SENIOR HYDROLOGIST $115.00 SENIOR ENGINEER $100.00 GRADUATE ENGINEER $ 85.00 SENIOR TECHNICIAN/CADD OPERATOR $ 55.00 SENIOR DESIGN TECHNICIAN $ 65.00 TECHNICIAN $ 45.00 SURVEY CREW $ 95.00 DRAFTSPERSON/CLERICAL $ 30.00