Officials pitch mobile "satellite" pumps to boost Henderson Bayou station capacity

District staff on May 12 proposed deploying mobile, semi-permanent "satellite" pumps at the Henderson Bayou pump station to increase drawdown capacity ahead of storms, saying the existing two 500-cubic-feet-per-second (CFS) pumps cannot be operated early without risking cavitation. The board discussed the idea but took no formal vote; staff said it will develop designs, cost estimates and contract documents and return for approval.

The proposal matters because, staff said, the Henderson Bayou station is permitted and configured so its pumps cannot be turned on until water reaches about elevation 4. "We're not supposed to turn the pumps on until it hits elevation four," the presenter said, adding that the station begins cavitating near elevation two and so cannot create pre-event capacity. The inability to draw down before a storm, staff said, meant the district battled rising water during the recent event rather than pulling levels down in advance.

The presenter displayed photos of the station and examples of mobile pump units observed in Terrebonne Parish, describing a concept in which multiple portable pumps would be placed at a levee intake to supplement the fixed pumps. He said roughly four portable units would be required to equal one of Henderson's 500 CFS pumps on a portable scale and that the units could be configured to be redeployable across sites. "It would take at least four pumps, portable pumps, to equal one of the pumps at Henderson," the presenter said.

Commissioners voiced broad support for testing the approach as a faster, lower-cost alternative to building an added full station. Commissioner Francis cited a homeowner account and a July 2021 flood, saying a reported high-water elevation of about 3.68 feet in that event illustrated the danger of the current pump-start threshold. "Not being able to turn the pumps on until 4 leaves a discrepancy that needs to be solved," Francis said.

Staff outlined next steps: if the board supports the concept, administration will move forward with design work, seek core (Corps) approvals and permits, and prepare contract documents and a budget request. On funding, staff recommended budgeting to self-fund initial design and procurement while pursuing state capital outlay or other nonfederal "quick money," characterizing federal funds as slow to materialize. "If it's not quick money and certainly not federal, we can just add 10 years to this project," staff said, urging the board to plan for local funding or capital outlay.

The board did not take formal action on the proposal at the meeting. Staff said they will return with designs, estimates and formal contract items for future consideration.