With Manatee County water supply contract set to expire in March 2025, Sarasota County staff at work on plans for filing the gap

Over past five years, Sarasota County has seen annual customer growth of about 10%

This graphic shows historical and projected water demand trends in Sarasota County. Image courtesy Sarasota County

Over the past couple of years, Mike Mylett, director of the Sarasota County Public Utilities Department, has noted at times that county staff was working to try to extend a contract with Manatee County, to allow Sarasota County to continue purchasing Manatee water after the agreement ends on March 31, 2025.

Sarasota County has been getting a maximum of 5 million gallons per day as a result of that contract, according to county documents.

During a Nov. 15 presentation to the County Commission, Mylett made it clear that Manatee County officials had declined to extend the contract.

Therefore, Mylett said, the Public Utilities Department has been engaged with staff of the Southwest Florida Water Management District (SWFWMD) on a modified permit that would allow the county to increase the water supply capacity of its Carlton Treatment Facility, which is located near Nokomis.

This graphic shows more details about water supply and demand in Sarasota County. Image courtesy Sarasota County

Further, staff is working on plans for new pipelines that would allow for more efficient distribution of water from the southern part of the county to the northern portion, Mylett added. That work will include a loop from Clark Road to Fruitville Road and Lorraine Road, he noted, emphasizing the importance of completing that initiative before the Manatee County contract expires.

Additionally, he pointed out, improvements at the county’s water treatment facilities and upgrading the water distribution system will cost approximately $268,140,000 through 2040.

Mylett’s comments came as he sought commission adoption of the county’s 2020 Water Master Plan, prepared by Carollo Engineers Inc., which was completed this August. The firm is based in Walnut Creek, Calif., though it has an office in Sarasota.

Mike Mylett is the director of the Public Utilities Department. File image

Mylett said he also needed for the board to accept the 10-year Water Supply Facilities Work Plan that Carollo had produced. Further, he sought authorization for county staff to go ahead with the processing of a county-initiated amendment to incorporate that 10-year work plan into the Comprehensive Plan.

The latter step was necessary, Mylett explained, to comply with Florida Statute 163.3177(6)(c). The addition to the Comprehensive Plan, by law, has to be undertaken within 18 months of SWFWMD’s adoption of its Regional Water Supply Plan. SWFWMD’s governing board adopted that plan on Nov. 17, 2020, according to a county staff memo in the Nov. 15 agenda packet.

On a motion by Commissioner Nancy Detert, seconded by Commissioner Michael Moran, the board members voted unanimously to take the steps Mylett had requested.

At the outset of his presentation, Mylett explained, “It takes, on average, seven to 10 years to bring on a new water supply.” Thus, he noted, the county’s planning horizon is 20 years. “We have to be looking out about 20, 30, 40 years …”

Chair Alan Maio, who represents the commission on the board of the Peace River Manasota Regional Water Supply Authority — which supplies the majority of the county’s water — has noted that the county has adequate resources to meet customers’ demand, Mylett pointed out.

Nonetheless, Mylett said, “We’re still seeing 10% increases in our number of accounts” per year, over the past five years.

The Carollo report says that, based on the county’s 2020 Public Supply Annual Report, which was completed as part of its SWFWMD water use permit conditions, the county’s potable — or drinking — water use by customer type was as follows:

  • 58.27%, single-family dwellings.
  • 15.86%, multiple-family dwellings, including mobile homes.
  • 16.03%, industrial/commercial.
  • 9.84%, water loss, which Mylett in the past has attributed primarily to leaking water pipelines that need replacement.

The Carollo report says that the average daily water demand “can be expected to increase to between approximately 25.90 and 29.18 [million gallons per day] by 2040 …”

A chart Mylett showed the commissioners said that the 2020 demand for water, on average, was 81 gallons per person per day (gpcd). For planning purposes, the chart noted, staff is estimating the usage to rise to 100 gpcd.

Among other details, the Carollo report points out that the highest demand for water during a single month from 2010 through 2020 occurred in March in both 2012 and 2020.

This chart provides details about the expense for types of initiatives to meet the county’s water demand. Image courtesy Sarasota County

It also noted that the county used, on average, 3.5 million gallons of water per day (mgd) from the Peace River Authority in the 2007 fiscal year. That had grown to 13.225 mgd by the 2011 fiscal year. Then, since the 2016 fiscal year, the average has been 15.060 mgd.

The maximum amount of water per that the county has obtained from the Authority from FY 2016 to the present is 21.084 mgd, a chart shows.

Actions underway and the planning stage

After rehabilitation work has been completed at the Carlton facility, Mylett told the County Commission, its capacity will increase from 12 mgd to 15 mgd.

Half of the Venice Gardens Water Treatment Facility (WFT) is out of service, he continued, because the reverse osmosis system “just is antiquated and doesn’t work anymore.” The previous week, he noted, staff was able to use it to produce 2 mgd, to supplement the Carlton plant while work continues at the latter facility.

The Venice Gardens plant will remain a facet of the county’s water supply production over the next 10 years, Mylett said. “It’ll be a high-service pump station in the future and a ‘tank farm’ for the southern portion of the county’s water supply system, he added.

This graphic provides details about the timelines for work to meet the water demands of county customers. Image courtesy Sarasota County

A slide Mylett showed the commissioners said that the planned rehabilitation of the Venice Gardens WFT would allow it to maintain production capacity of 1 mgd through 2025, when it would be “converted into a ground storage tank and pumping facility.”

Another water source is the University Wellfield, located in the north-central portion of the county, the Carollo report explains. That wellfield has seven active wells that produce an average annual capacity of 2 mgd.

This graphic shows the locations of the county’s water treatment facilities and offers details about the one at University Parkway. Image courtesy Sarasota County

Around 2030, Mylett told the commissioners, after the Peace River Authority has constructed and filled a new reservoir, the county most likely will get more water from the Authority.