Title
Consider and take action on a resolution authorizing an amendment to the professional services agreement with Lockwood, Andrews & Newnam, Inc. for added Drainage Modeling work related to the Bensons Bayou Detention Project, Phase 1 (DR2006) in an amount not to exceed $64,440 (Director of Engineering)
Background:
Approval of this resolution will authorize the City Manager to execute an amendment with Lockwood, Andrews & Newnam, Inc. (LAN) to further analyze Benson Bayou to determine the volume of detention necessary along Benson Bayou for flood risk reduction while accounting for Atlas 14 based rainfalls in an amount not to exceed $64,440.
In November 2019, Council approved a Professional Services Agreement with LAN to provide preliminary engineering services for drainage improvements along Benson’s Bayou. The PSA was for an amount not to exceed $379,250. These fees were split between an H&H study for a segment of Benson Bayou and related additional services that may have been needed. The crux of the initial PSA was based on an H&H study of the portion of Benson Bayou primarily between SH 96 and FM 646. This area had originally been identified in the City’s 2014 Master Drainage Plan, Phase 2, so the first step in this current project was going to update that study area using the new Atlas 14 rainfall intensity rates. Also, as part of this agreement, LAN was to provide 2 options for staff to consider related to drainage improvement projects. The goal of these options was to reduce the potential for flooding in affected neighborhoods while increasing the capacity and conveyance in Benson’s Bayou.
The initial H&H study was completed in late February 2020 and confirmed that Benson Bayou is inadequate for major rainfall events which results in widespread street flooding and in extreme cases, structural inundations.
The first option the study evaluated as a potential solution was for new detention storage to be constructed in the open area adjacent to Bens...
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