Low Impact Development

Weeki Wachee Rogers Park

HSW Engineering was retained by the Southwest Florida Water Management District (SWFWMD) to provide a retrofit design of an existing parking area and stormwater management system utilizing Low Impact Development (LID) techniques.  LID is an approach to stormwater design which seeks to replicate the pre-development hydrology of a site by minimizing site impact and through the use of specifically designed Best Management Practices (BMPs). The retrofit design will enhance water quality on the Weeki Wachee River, an Outstanding Florida Water and first-order magnitude spring system, by reducing pollutant loads from the park. The enhancements will provide for direct infiltration of stormwater runoff into subsurface soils with subsequent treatment of excess runoff in bioretention cells.

Services provided by HSW included stormwater management design, development of construction plans, environmental permitting (i.e., 10/2 General Permit), engineering economic studies, project management and quality assurance/control.

The LID practices incorporated in the design include:

  • Re-graded parking and drive areas that lengthen flow paths and increase time of concentration;
  • Parking and drive areas re-surfaced with porous asphalt to increase storage capacity and infiltration rate;
  • New exfiltration system beneath parking and drive areas to increase percolation;
  • New trench drain to re-direct sheet flow from a directly connected impervious surface to the new exfiltration system; and
  • New bioretention cells (2) to increase infiltration.