Title
Consider and take action on a resolution authorizing a professional services agreement with LJA Engineering, Inc. (LJA) for design work related to the City-Wide 2-D Drainage Model (DR2007) in an amount not to exceed $772,588 (Director of Engineering)
Background:
Approval of this resolution will authorize the City Manager to enter into an agreement with LJA design work related to the City-Wide 2-D Drainage Model for an amount not to exceed $772,588.
In 2010, the City commissioned a Master Drainage Plan. The first phase of this plan was completed by Dannenbaum Engineering in December 2010 and concentrated primarily on updating the previous 1990 City Master Drainage Plan’s hydrologic and hydraulic models, aerials, drainage areas within the City, Tributary Model updates, and incorporating the most current FEMA floodplains. A second phase of the Master Drainage Plan was completed in April 2014 by LAN Engineering. This second phase primarily established drainage projects and prioritized them into a five (5) to seven (7) year implementation plan.
Since the 2010 model updates, the City’s population has grown by approximately 20,000 people and we have seen new development in previously undeveloped areas on the western side of the City and the eastern side of the City is almost fully developed at this time. In 2019, FEMA updated the flood plain maps for this area and NOAA released their Atlas 14 Paper which showed that the industry standard rainfall intensities that engineers had been using for years to aid in the design of stormwater systems was inaccurate. The Atlas 14 paper provided new rainfall intensities for our area.
In the aftermath of the Hurricane Harvey flooding, City Staff began working towards securing grant funding to assist with an update to the City’s Master Drainage Plan. In May 2018, Staff submitted a Notice of Intent (NOI) for a City-Wide 2-D Drainage Model project to the Texas Hazard Mitigation Grant Program (HMGP). This NOI was accepted...
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