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March was the driest on record in Florida. Can the Everglades cope?

Adriana Brasileiro, Miami Herald on

Published in Weather News

MIAMI -- In the Everglades, it's all about the water.

The fragile ecosystem hasn't seen much rain during this unseasonably dry season and by the time summer arrives, sea grass could be dying and the rich peat soil that supports life could be collapsing.

"One of the meteorologists at the district characterized the month of March as showing 'exceptional, long-lived, unprecedented dryness,'" said John Mitnik, chief engineer at the District South Florida Water Management District. "Basically it didn't rain and it was very dry," as he pointed to a graph during a video conference meeting in which district board members were warned about potentially dire consequences of the "big red deficit of rainfall" last month.

South Florida may have seen some thunderstorms over Easter weekend but the rain hardly dented the scorching trend that has dried off canals and led water managers to impose strict irrigation restrictions April 10. The region is heading into dangerous weather territory as the first three months of the year were the hottest on record, creating conditions for soil collapse in the Everglades and sea grass die-offs in Florida Bay.

March was the hottest month on record for Florida, with an average of just 0.24 inches of rain -- the driest in 89 years, according to the Water Management District.

The deepening drought has lowered Lake Okeechobee to worrisome levels, while many groundwater wells are drying up. The lake irrigates farms and fills up canals that help prevent saltwater intrusion across South Florida. It also serves as a backup water source for many cities during times of drought.

The situation was so extreme last month -- with water conservation areas falling below safe levels -- that water managers last Friday stepped up water restrictions, ordering residents to cut landscape irrigation to just twice a week, between 7 p.m. and 7a.m. with no more than an inch of water applied to lawns each week.

While water is being allocated for agricultural use, there is hardly any freshwater flowing south into Everglades National Park, as a recent presentation at the district's monthly board meeting showed.

Big Cypress National Preserve was among the areas with the biggest rainfall deficit, Mitnik said.

The water that's flowing south for water supply maintenance in southern Miami-Dade County isn't enough to make it to Taylor Slough, a key conduit that takes freshwater south to Florida Bay. A large portion of Taylor Slough, which stretches from the east Everglades to the northern part of Florida Bay, is located inside the park, and is visible from the Anhinga Trail boardwalk near the Royal Palm visitor center.

It's an area that should always have deeper water than the surrounding marshes, and where a slow current is present, like a shallow and slow-moving river.

With water depths decreasing dramatically since the start of the year, nothing is making its way south to Florida Bay, and salinity levels have become critically high, Lawrence Glenn, the district's water resources chief, said during the video conference meeting of the governing board.

"There's concern that we are in the same sort of setup for the sea grass die-off that we saw in 2015," he said.

A drought in South Florida that began in 2014 and continued into 2015 severely reduced freshwater flows into Florida Bay. This period of low rainfall, high temperatures and calm winds increased evaporation, leading to a spike in salinity levels inside the basins in Florida Bay.

 

Within Garfield Bight, for example, water temperatures exceeded 93.2 degrees for more than 77 days and reached a maximum water temperature of 100 degrees at the end of July. That combination of factors led to a catastrophic collapse in the bay's ecosystem.

Florida Bay's sea grasses aren't the only potential victim of this year's record-dry conditions: peat soil, an essential component of the Everglades, is also at a higher risk of collapsing. As less freshwater flows through the River of Grass, salt water is moving farther inland. Saltwater intrusion and the drying up of the marshes can lead the soil to break down, with elevation dropping quickly, exposing the roots of the vegetation, which eventually dies.

"This is a time when these marshes are most vulnerable to the drivers of peat collapse," said Stephen Davis, a senior ecologist at the Everglades Foundation. "It starts with exposure to salt water, followed by the drying off of those areas. We are seeing these two factors right now."

Davis said the completion of fresh water restoration projects is critical to give the fragile ecosystem a chance at staying properly hydrated, or at least in a condition that's similar to how the Everglades functioned before it was severely altered over the last century.

A key project is a massive storage reservoir and treatment area south of Lake Okeechobee that's supposed to hold about 78 billion gallons of water. The basin is designed to divert polluted water from Lake Okeechobee that is now sent down the Caloosahatchee River to the west and the St. Lucie to the east, flows that have contributed to fish-killing algae blooms.

The project will also help send more water south, passing it through treatment areas and toward the water-starved southern Everglades marshes and Florida Bay. There is no date for completion of the project.

The district will build a large stormwater treatment area while the U.S. Army Corps of Engineers will construct the reservoir in the joint state-federal project.

In the meantime, all managers and conservationists can do is pray for rain.

"We will be watching what's going on here, and waiting for the rain," Glenn said.

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