Countywide Underdrain Infrastructure Improvements

Description

Throughout St. Johns County, underdrain is installed along roadways in residential areas as a means of controlling groundwater levels and conveying it into the storm sewer system. Underdrain construction consists of open trench excavation, rock bed installation, placement of perforated plastic pipe wrapped in filter fabric with rock backfill. Over time these systems age and deteriorate or are damaged during irrigation system or utility installations. Underdrain failure is typically caused by a blockage or when soil penetrates and moves thru the conveyance system forming a void around the underdrain. These voids cause the material above them to settle such as driveways, curb sections or asphalt pavement. The CUI Program will address these failures and prevent further damage to County assets. The Fiscal Year 2025 budget for this project is $500,000.