An environmental engineering firm has submitted a preliminary plan to the town of Oak Bluffs for fixing an enormous puddle that spans County Road in even moderate rainstorms.

Horsley Witten Group of Randolph studied the drainage environment near the Trade Winds Field Preserve and determined that approximately 35.5 acres of land drain into that one spot, creating a hazard that often lasts well after the rain stops.

In its summary, the report says the proposed improvements would eliminate the flooding during the worst storms.

“Storms greater than a one-year event may result in some ponding at the low point but a much lower level,” the report found. “Additionally, sediment suspended solid loads reaching the current flooding issue would be greatly reduced.”

The engineering firm said one persistent problems is sediment that flows toward County Road, overwhelming previous attempts at installing drainage systems.

“We did install some drainage there about six years ago,” said Oak Bluffs highway superintendent Richard Combra Jr. “but it’s failed because of the runoff from private property that is full of silt and mud which has destroyed the drainage and clogged all the stone that’s on the edge of the road there. We have to move to the next level. It’s gotten a little bit worse in the last couple of years.”

The plan is to stabilize paved and packed surfaces in the drainage area, install several graded areas with basins to catch sediment before it gets to a new drainage system, which will include sub-surface infiltration chambers, and enhanced surface infiltration at the low point in the topography.

“We still have a little bit of discussions with the land bank on installing it,” Mr. Combra said. (The land bank owns the preserve.) Mr. Combra said the town will also need to discuss repairs with private landowners in the area. “Now that we have the report we can move forward with talking with them,” he said.

The engineering report includes a preliminary cost estimate of $252,956.

Mr. Combra said the town has saved its annual allotment of state highway funds, known as Chapter 90 funds, over the last two years in anticipation of funding the drainage project.

“My hope is to have construction early spring and be done before the summer season starts,” Mr. Combra said. “We’ll use Chapter 90 funds that are already in place.”