Sarasota County to need another 12 million gallons of water supply per day within 20 years, Public Utilities director tells commissioners

Population growth driving higher demand

This chart shows water demand projections through 2045 for Sarasota County. Image courtesy Sarasota County

As part of his final appearance this week before the Sarasota County Commission, with his retirement pending, Mike Mylett, director of the county’s Public Utilities Department, pointed to the growth in water demand, especially over the past three years.

Within the next 20 years, Mylett said, the county will need another 12 million gallons of water per day (mgd) to serve its customers.

This year, he noted, the county experienced its first day ever of demand that hit the 30 mgd mark.

Over the 25-year history of the county’s system, he told the board members on Nov. 14, “We’ve had a pretty consistent growth rate on our utility.” Overall, Mylett continued, that rate was just under 2% per year. However, he added, “We’ve really grown really dramatically over the last three years.” During that period, the annual rate has been 5%.

“The growth is challenging our systems,” Mylett pointed out.

Yet, he continued, Sarasota County is not alone in that situation. “Our neighbors are experiencing the same growth rates.” He was referring to Charlotte and Manatee counties, Mylett noted.

By 2045, a slide showed, the county’s customers are anticipated to need 37.62 mgd. The actual estimated demand per day this year is 25.94 mgd, the slide noted.

Then, referring to another slide, Mylett added that the county is paying for about 15 million gallons of water a day from the Peace River Manasota Regional Water Supply Authority, in which it is a partner, along with Charlotte, DeSoto and Manatee counties. The City of North Port is a customer of the Authority, he noted.

This slide shows details about the population growth in Sarasota County and neighboring counties, plus the City of North Port. Image courtesy Sarasota County

Just last week, he reminded the board members, they participated in the commissioning of the second phase of improvements at the county’s T. Mabry Carlton Jr. Water Treatment Facility near Venice, which has the capacity to provide 12 mgd. Recently, he added, the county received the necessary permits to be able to withdraw that much water from the treatment plant.

Additionally, he continued, staff has been able to extend its contract to purchase water from Manatee County for three more years.

Nonetheless, Mylett said, “We’re seeing, as we continue through the years, we’re going to need additional water.” Already, he added, staff has told the leadership of the Peace River Authority that the county will need 4 mgd more by 2028. “They’re planning on that right now.”

Then, he emphasized, “We’re going to need an additional 8 million gallons,” above the extra 4 mgd, by 2045.

He also explained, “It takes on average seven to 10 years to put new supply online, for it to be usable.” Therefore, Mylett added, staff has to tell the Authority seven years in advance about the extra water it will need at the end of that window.

Because the county expects to need the first additional 4 million gallons of water a year by 2033, he continued, staff will have to sign “on the line” for that amount in 2026.

The goal of his Nov. 14 presentation, he noted, was to receive County Commission approval to provide the county’s latest water demand projections to the Peace River Authority, to help the organization in its planning. That annual action is a requirement of the county’s agreement with the organization, he said.

The Authority is working on construction of a new reverse osmosis treatment facility for brackish groundwater that would provide an extra 9 mgd, Mylett said, as well as an expansion of its 9-billion-gallon surface water reservoir and its 18-mgd surface water treatment plant. The total expense of those initiatives is almost $500 million, he pointed out.

This graphic provides further details about projected water demand in Sarasota County. Image courtesy Sarasota County

The debt service on bonds for the Authority projects would be “roughly about $7 million a year,” he said.

Representatives of the Authority also have begun working with staff of the Southwest Florida Water Management District (SWFWMD) and the Legislature to try to win funding to help reduce the overall expense of those initiatives, Mylett noted; he believed that the Authority had won assurance that it would be able to get about $100 million. That would leave the partners in the Authority with having to cover the rest of the expense, which could run as high as $375 million, he said.

In the spring of 2024, Mylett said, staff will come back to the commissioners with a contract calling for the initial, additional 4 mgd by 2028.

Following the presentation, Commissioner Neil Rainford made the motion to approve the water demand documentation for the Peace River Authority, and Commissioner Michael Moran seconded it; it passed 5-0.