From
Maxine Snow
Title
Dalworth Street at Dalworth Creek Drainage Improvements Amendment/Change Order No. 1 to Engineering Professional Consultant Services contract with Pacheco Koch, LLC., in the amount of $70,508
Presenter
Romin Khavari, City Engineer
Recommended Action
Approve
Analysis
January 19, 2017, the City of Grand Prairie awarded a preliminary concept design contract in the amount of $43,625.00 to Pacheco Koch, LLC for two street crossings of Dalworth Creek, at Dalworth Street and NW 2nd Street. The preliminary concept design analyzed the existing storm drain culvert crossings for various frequency storms and provided recommendations for drainage improvements for this reach of Dalworth Creek at these street crossings.
At the Dalworth Street location crossing Dalworth Creek, the preliminary concept design recommended replacement of the existing two 48 inch diameter reinforced concrete pipe culverts with two 8 foot by 7 foot reinforced concrete box culverts to provide a 100-year flood protection at Dalworth Street and channel bank protection upstream and downstream of Dalworth Creek. This location is along a heavily travelled thoroughfare serving this area of the city and these drainage improvements are recommended.
At the NW 22nd Street location crossing Dalworth Creek, the preliminary concept design recommended that the two 2- 7' X 4' Box Culvert at this location remain in place and that due to specific constraints at this location that only staff gage, signage and future flashers be installed to warn against this roadway flooding during the high flows. This location is along a residental street and the preliminary design evaluation determined that the home finished floor elevations adjacent to this location are above the existing 100 year water surface elevations.
This proposed Change Order/Amendment No. 1 in the amount of $70,508.00 to the contract provides for the design of the recommended drainage improvements at Dalworth Street and channel bank protection improvements along Dalworth Creek. Design of the new drainage culverts will provide flood protection for Dalworth Street at the Dalworth Creek drainage crossing for the 100-year storm event. The project scope includes the relocation of the existing 12 inch wastewater line and 12 inch water line if needed.
Design of this project is anticipated to begin in August 2017 with completion in March 2018, with bidding and construction services to follow once the easements are obtained. This engineering services contract will last until construction of this project is completed currently estimated by the end of August 2018.
Financial Consideration
Funding for the Dalworth Street at Dalworth Creek Drainage Improvements Amendment/Change Order No. 1 to Engineering Professional Consultant Services contract with Pacheco Koch, LLC., in the amount of $70,508. is available in Storm Drainage Capital Projects Fund (401592), WO #01705603 (Dalworth St at Dalworth Creek) 68560. Funding for construction is being requested as part of the FY18 CIP Budget Consideration.