Monday, March 8, 2021

Are we running dry?

Weir at Rt 41 Aug 19 2008. Submitted photos

Weir at Rt 41 Aug 19 2008. Submitted photos

By Danielle Dodder

A drought can feel deceptively non-urgent when you live on an island surrounded by water, until the smoky haze of wildfires to the east drifts downwind. Residents of South Florida are long used to being told not to overwater their lawns during dry season, so it’s easy to overlook the black and yellow ‘Severe Drought’ signs posted along State Road 951.

According to the South Florida Water Management District (SFWMD), the signs are anything but pro-forma; October to February saw the driest season in 80 years. “We are incredibly dry throughout the entire district,” explains SFWMD representative Gabriel Margasak.

“As a backdrop, we started the season on the Southwest Florida coast having gotten only 58% of the average rainfall,” adds Margasak. According to the National Weather Service, a La Nina condition is helping foster drier conditions. “We are expecting the upcoming [rainy] season to be average or below average. It’s a concern.”

The only way to recharge the system is through the seabreeze cycle that pushes moisture onshore and creates summer rain showers. “We need the everyday soakings to get back the water levels,” says Margasak. He adds that weeks of steady rain are necessary to break the drought. Currently, SFWMD is monitoring conditions 24 hours a day through hundreds of rain gauges. “We’ve been keeping records since 1932. It’s a sound science,” says Margasak.

 [/caption] href=””>As the District works to allocate scarce water, the city of Marco Island has gotten a lucky break. The lake that supplies Marco’s aquifers is currently about 1.6 feet above sea level: “not typical,” according to Dr. Bruce Weinstein, senior project manager for the water utility.

The previous dry season saw freak February rainfalls in our area that gave the lake, which supplies about three million gallons of water to the island daily, a boost that has lasted even as the utility has had to pump extra water from it. Another three million gallons per day comes from the ASR well system under the lake, which can store slightly over one billion gallons in a freshwater ‘bubble.

“We have to fill the well in three months, then we need that water to last a year,” explains Weinstein. “Let’s say the drought stays, we can increase the difference with [pumping] the water in the ASR.” According to Weinstein, the ASR can supply water to the island for ten months without touching the lake, if need be.

The city’s reverse osmosis wells are a drought- immune, if expensive alternative, to capturing surface water. The water that supplies them fell to earth somewhere between 30 and 50 thousand years ago, according to SFWMD geologists. Unfortunately, our proximity to the Gulf

Marco Lakes, Raw Water Plant, 7130 Collier Blvd.

Marco Lakes, Raw Water Plant, 7130 Collier Blvd.

means the water has a high salt content and “the higher the salt content, the higher the cost” to make the water usable, says Weinstein.

Keeping the scenery green when no rain is falling is the biggest water waster for SFWMD to fight. “50 percent of potable (drinkable) water is used for irrigation,” says Margasak. Consequently, SFWMD promotes water reuse as a policy and compliance is high in the District overall.

In contrast, just three percent of Marco irrigation is done with reuse water, according to the recent study released by Burton and Associates.

Both Margasak and Weinstein agree that water conservation needs to be a long-term cultural habit to ensure a healthy water supply. Water use on the island has dropped significantly from its growth peak in 2003, when daily water use averaged about nine million gallons per day. Weinstein’s data show that in 2010 it reached an all-time low of 6.6 million gallons per day.

Whether this drop is due to block rates on water bills inducing conservation, or a reaction to rising costs of water during a severe economic pinch is debatable.

As the SFWMD watches ever-shrinking basins, Margasak’s message is clear: “Be mindful when you use water at home. There are approx. 7.7 million people in the area. If every one of them turned the water off when they brushed their teeth, think of the amount of water saved.”



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