Posted on June 25, 2019
Orange Beach, Alabama has been asked to administer $475,000 of a $3 million Restore Act project studying hydrology and sediment in Perdido Bay from the U.S. 98 bridge in Lillian to the Gulf of Mexico.
“It’s a three-part study for beneficial use of dredged sediment,” Coastal Resources Director Phillip West said.
“The state reached out to us because we have done almost like a phase one for the lower Perdido and that’s one of the three sites to study. Because we had coordinated that they asked us if we could take all the lower Perdido studies, manage those and direct the contractors and consultants.”
The city council OK’d the agreement with the state during the June 4 joint regular session and work session.
Areas in the study include the Denton Oyster Reef, a feasibility study on the restoration of Grand Bay, Mississippi, barrier islands and studying sediment movement in the lower Perdido Bay/Pass area from the U.S. 98 bridge in Lillian to the Gulf. The study is being done in advance of the dredging of the Mobile Harbor Navigation Project and how to use materials removed to deepen and widen the channel.
This would include “complete planning, design, engineering, and feasibility assessments for three project areas where future placement of dredge sediments would achieve habitat restoration. Designing habitat restoration projects that are ready to utilize such materials saves money, creates habitat and is a Gulf-wide objective of the Gulf Regional Sediment Management Master Plan.”
The first step, West said, would be to seek proposals from firms who are interested in conducting the study.
“We’ll put out requests for qualifications once we finalize this agreement with the state,” West said. “Once they give us the green light to do announcement and begin the actual work then we’ll proceed hopefully with the whole process. You put the request for qualifications out for 30 days.
You have the committee score those respondents, select one, negotiate and award the contract. I’m thinking maybe three months.”
Movement of sediment throughout Perdido Pass and the bay will be tracked. The pass is a vital part Orange Beach’s charter fishing program.
“Determining all the forces that go toward moving sediment, displacing sediment, causing erosion, causing hotspots, even accretion if that’s the case, or shoaling,” West said. “Then we’ll determine what is the total sediment budget, what are some of the dredging intervals and how do we best use that sediment in the most beneficial manner to not only mitigate erosion but develop habitat over a long term. When you’re looking at forces that have always been there in the watershed but also, we are considering sea level rise with everything we do along the shorelines now.”
Studying how the U.S. 98 bridge affects the flow of sediment at the north end of the project area will likely be included.
“We’ll have a report for the sediment management study, we’ll have a report for the hydrological study, we’ll have a report for the natural resource inventory,” West said. “We’re probably looking at the 98 bridge or the Lillian bridge. You do have the bridge there that would have some influences and to some point north of the bridge. I’m not sure what the engineers would tell us is sufficient to capture the 98 bridge’s influence on this hydrological element.”
Source: coastalnewstoday.com
