Title
Consider and take action on a resolution authorizing a professional services agreement with Kimley-Horn and Associates, Inc. (K-H) for design work related to the Magnolia Creek and Cedar Gully Channel Improvement Project (DR 1906) in an amount not to exceed $924,200 (Director of Engineering)
Background
Approval of this resolution will authorize the City Manager to enter into an agreement with K-H to design drainage improvements along Magnolia Creek and Cedar Gully for an amount not to exceed $924,200.
In 2014, a drainage study for League City was conducted by LAN Engineering. The study recommended an erosion control project for portions of Magnolia Creek and Cedar Gully. The study recommended 2 primary mitigation actions:
• Modify the outlets of 3 detention ponds so that the stormwater inflows are stored in the ponds and discharged at a rate to reduce impact to flows in the channel during 1% exceedance events.
• Modify the Summer Place Culvert crossing in Mag Creek to match the dimensions of the channel section upstream of the crossing.
A secondary action was to address the existing erosion issues which could mean removal of dead and diseased trees and trees within the channel/channel banks or near the top of bank (if there is risk of falling), correct the channel’s cross-section to a more uniform earthen pattern, and riprap around existing discharge points in an effort to reduce further erosion within Magnolia Creek and Cedar Gully.
The Magnolia Creek and Cedar Gully watersheds provide drainage for over 2,000 homes and several dozen commercial developments within League City. In the aftermath of the Hurricane Harvey flooding, Staff saw deterioration along these channels and began working on scoping an erosion control project. Staff submitted grant applications to Texas Hazard Mitigation Grant Program, but the project did not meet the minimum Benefit-Cost Ratio to be considered for funding. This project was included as part of a list of drainage proj...
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