Aransas County commissioners, at their regular meeting Monday, Nov. 9, heard a report from Mott MacDonald Engineering’s Aaron Horine about the plans for the opening of Cedar Bayou this spring.
Work on the $8,959,700 project is scheduled to begin in April 2021.
The cost breakdown for the project is:
• FEMA - $6,427,574
• TP&WD Fisheries Enhancement Program - $1,000,000
• Texas Department of Emergency Management - $535,630 (75% of the 10% match
• Aransas County - $178,543 (25% of the 10% match)
• Aransas County - $817,953
(Note: Congressman Michael Cloud and State Representative Geanie Morrison attended a kickoff event Aug. 17 in Rockport for the restoration of Cedar Bayou at which the federal and state funding was announced, and the aforementioned figures were released.)
At Monday’s meeting, Horine addressed the 95% Design Approach, recent data collection, modeling and analysis, estimated costs, and the path forward.
95% Design Approach
This basically means plans are approximately 95% complete, and when final FEMA approvals, etc. are finished, Request of Proposals will go out.
The plans call for minimal impacts to sensitive habitats, reduced dredge volumes, a more natural channel (matching historical channel alignments), and maximum flow through Cedar Bayou and Vinson Slough.
Horine noted recent hurricanes, which passed by Aransas County, actually reconnected the bayou to the Gulf of Mexico at moments of extreme high water. He also said although Hurricane Harvey pushed sand into the bayou and slough, it also lowered the Gulf side sand level at the mouth (to the Gulf).
A habitat survey identified 13 habitat types, and areas of sensitive habitats.
The importance of avoiding those habitats, when designing the proposed dredge template, was noted, as well.
Horine then showed a picture of the historical channel centerlines dating back to 1969 (10 years before Cedar Bayou was plugged as a protective measure after the Ixtoc oil well blowout in the Bay of Campeche). Those natural flow paths and trends were used to help guide the design of the dredging project
Modeling and analysis
Based on circulation modeling, Horine noted the previous dredging model, which has basically a straight cut in the bayou, and slough, will not be used this time. Instead, the channel will take on a more meandering look. Cedar Bayou will enter perpendicular to the Gulf.
Horine noted there are two approved dredge disposal sites, and the one furthest away from the mouth of the bayou will be used. This will mean fewer blockages to natural migration (changing path of the channel).
Commissioner Charles Smith asked if there is any advantage to annual maintenance dredging once Cedar Bayou and Vinson Slough are dredged.
Horine said the cost of mobilizing equipment would make that cost too high.
No specific costs were presented, since those presented at the August funding announcement.
Bid opening for the project, as well as awarding of contract, should be completed by the end of this year.
Mobilization to site is planned for the end of April 2021, with dredging to start June 5.
The project must be finished by Nov. 1 before the whooping cranes make their return to the Aransas National Wildlife Refuge.