MANASOTA & PEACE RIVER BBDs Meeting Notebook 10-21-09.docx

L615
Sarasota Imp. BMPs Alligator Creek
Project Type Cooperative Funding
AOR(s)
Flood Protection, Water Quality
Basin(s) Manasota
Cooperator(s)
Sarasota County
Project Manager SMITH, RANDY
Task Manager(s)
Status Ongoing
Description
This is a multi-year funded project to perform an element of the District's Watershed Management Program (WMP) for
the Implementation of Best Management Practices (BMPs) in the Alligator Creek Watershed. The watershed covers
an area of approximately 10.7 square miles and is located in Sarasota County. This project will implement several
improvements in the following areas: 1) Banyan Drive - culverts and pond expansion with wetland plantings, 2)
Briarwood area - upsizing of culverts and outfall pipe, 3) Bal Harbour Drive - stormwater collection system, 4) Venice
East Drive - modify the control structure at Heron Lakes, and 5) Venice East Boulevard - installation of box culvert.
Several of the roadways contiguous to these improvement areas become impassable during the 10, 25, and 100-year
storm events that result in a health and welfare threat to residents by creating changes in traffic flow and emergency
vehicle routing. In addition, the project is expected to improve water quality by installing several Nutrient Separating
Baffle Boxes to reduce non-point source pollutant loads. This project is also expected to improve water quality by
increasing residence time through conversion of the old Briarwood wastewater treatment percolation ponds into
stormwater ponds and by expanding the existing lake system storage capacity. This project includes construction of
the BMP only.
Benefits
The project is expected to meet level of service criteria during a 25-year storm event, improving roadway access by
increasing conveyance and providing additional storage in the watershed. The project is also expected to improve
water quality by increasing residence times and installing several Nutrient Separating Baffle Boxes to reduce non-point
source pollutant loads. According to the County, the project will provide approximately $2.3 million in present-value
flood mitigation benefits assuming a 50-year useful life.
Costs
The total budget amount for this project is $4,220,000, of which the District's share is $1,500,000 over FY2007,
FY2008 and FY2011. The District appropriated $750,000 in their FY2007 budget and $375,000 in their FY2008
budget. The County withdrew its FY2010 funding request of $375,000 because those funds would not be expended
until FY2011. The County will request the remaining funds in FY2011 to complete the project. The District's share is
being funded entirely by the Manasota Basin Board. The County budgeted $2,720,000 over FY2006, FY2007, FY2008,
and FY2009. When each task is completed the project budget may require refinement based on the information
gathered. The District funding amounts shown in the table include staff salaries, travel and central garage charges.
Additional Information
The WMP includes five major elements: 1) Topographic Information, 2) Watershed Evaluation, 3) Watershed
Management Plan, 4) Implementation of BMPs, and 5) Maintenance of Watershed Parameters and Models.
Implementing elements of the WMP with local governments is one of the Comprehensive Watershed Management
(CWM) initiative strategies. The probable construction cost for this project was based on the BMP alternative analysis
developed by the County in its Alligator Creek Basin Master Plan. The County previously budgeted funds for the
project design, development of construction documents, construction permitting, land acquisition, and bidding and
contractor selection. The County will be required to acquire easements in order to implement the BMPs. A cooperative
funding expenditure agreement with County was developed as a multi-year funded project contingent on the approval
of future funding to complete the Implementation of BMP's. The County will manage the project, where the District
project manager must approve any agreements to accomplish project tasks.
021 - Manasota Basin 300