Dona Bay Watershed 1507130330

Dona Bay Watershed Restoration Program

Case Study

Dona Bay Watershed Restoration Program


Dona Bay Watershed Restoration Program


Sarasota County, Fla., Public Utilities Department


The Cow Pen Slough was constructed in the 1960s. The change in regional drainage increased the Dona Bay watershed from 15 to 75 square miles by redirecting 60 square miles from the Myakka River watershed. As a result, Dona Bay was adversely affected by significantly increased freshwater inflows, reducing salinities to levels incompatible with native flora and fauna and increasing nutrient loads to Dona Bay. The change also reduced freshwater flows to their original destination, the lower Myakka River and the downstream waters of Charlotte Harbor.


With previous experience in Florida, Sarasota County contracted with Glover Construction to update its conveyance system. With a 200-acre site, the scope of work included clearing, erosion control, 1.1 million cubic yards of earthwork, placement of stone on roads, as well as the update of the existing ponds. These ponds serve as a natural filtration system for the water flowing out of the canals before it enters the wetland. Glover Construction also installed nearly one mile of 72-inch concrete pipe. During the peak grading period, Glover Construction hauled an average of 10,000 to 15,000 cubic yards per day. As a result of the project, more than 18,000 pounds of nitrogen are removed annually for less than $40 per pound.


The scheduled completion date was May 2017. However, the project was completed significantly ahead of schedule, despite excessive winter rainfall and Tropical Storm Hermine. Approximately 95 percent of the project was completed by December 8, 2016. The water quality benefit to Dona Bay and the public began in November 2016 when Phase 1 of the project was effectively operational with Cow Pen Slough diverted via the concrete diversion dam through the project.

Additionally, no injuries were reported for the duration of the project, and it won multiple awards,:

  • The 2017 American Public Works Association – Florida Chapter Environment Project of the Year
  • The 2017 American Society of Civil Engineers SunCoast Branch (Florida) Project of the Year
  • Additionally, this project was nominated for the National American Public Works Association Environmental Project of the Year for the $5 million – $25 million category

Contract Value: $11 million