26-2703: Resolution - A Resolution of the City Council of the City of Mansfield, Texas, Approving Professional Services Contracts Between the City of Mansfield, Texas and Westra Consultants, LLC for Design Services and Brittain & Crawford, LLC for Surveying Services, and Approving Funding in an Amount Not to Exceed $474,000.00 for the Design of the Willowstone Pond & Downstream Drainage Improvemen

Staff Report & Agenda Item Details

As a result of flooding that occurred in 2022, staff contracted an analysis study December 12, 2022 of the drainage area for the Willowstone Estates detention pond. The analysis report dated May 4, 2023 concluded the initial design of the pond was undersized by roughly half. A feasibility study was authorized July 8, 2024. The feasibility report dated January 29, 2025 concluded improvements to the pond were necessary to provide adequate protection from flooding for downstream properties. The proposed scope of work is to design construction plans for a pond expansion to be completed as soon as possible. Initial engineering for the pond expansion was completed as part of the feasibility study. The work to expand the pond capacity is completely located within existing drainage easement and construction can be authorized as soon as plans are completed. Expanding the pond alone will significantly increase the level of service for the pond and reduce flooding frequency to downstream properties, but does not meet the typical design standard for protection from a 1% storm event. Concurrent to the pond expansion design, the consultant will design a new underground system to receive floodwaters from the expanded pond, convey those flows along existing right of way in Spirit Walk St, and eventually discharge into an existing storm drain box culvert located in The Trails subdivision on Goodnight Trl. This will include initial evaluation of different scenarios to evaluate cost effectiveness. The additional storm drain work will require new easements and take considerably longer to design. The sequence was presented to a stakeholder group of local residents in a meeting with staff in order to provide as much protection from flood risk as quickly as possible. The proposed scope covers the cost of design for construction plans for all improvements, initial survey to support the design, investigative survey to ensure utility conflicts are avoided, and preparation of necessary easeme

This motion is scored as EXPANDS_GOVERNMENT (Impact Weight: 4.9/10). Under the Bastiat Liberty Watchdog Index, measures that increase tax rates or fee schedules, issue new debt or Certificates of Obligation, expand regulatory/zoning restrictions on private land use, or authorize unbudgeted spending expansions reduce an official's Freedom Score when voted YES (and reward dissenting NO votes).