WEATHER

Loxahatchee River suffers after blue-green algae outbreak

Kimberly Miller
kmiller@pbpost.com
Park manager Mark Nelson guides his boat through the Loxahatchee River in Johnathan Dickinson State Park in Martin County, Florida, August 27, 2018. (Greg Lovett / The Palm Beach Post)

Palm Beach County was largely spared last summer’s scourge of algae that bled toxic streams of green into northern estuaries, but it didn’t escape entirely, and one treasured waterway still suffers.

The Loxahatchee River, one of only two federally designated Wild and Scenic rivers in Florida, is getting less fresh water than recommended after the City of West Palm Beach detected algae in a canal that sends water through Grassy Waters Preserve into the river during the dry season.

The city shut off its canal feed from Lake Okeechobee in May, and as the preserve dried down because of lower summer rainfall and no supplemental lake water, it couldn’t send water to the river.

As of Friday, recommended flows of 50 cubic-feet-per-second (cfs) of fresh water needed to fight saltwater flowing in from the Jupiter Inlet haven’t reached the river since Oct. 26. Since then it has fluctuated between 3.6 cfs and 48 cfs.

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While it would take 20 consecutive days of flows below 35 cfs for the saltwater to cause significant harm to the Loxahatchee’s flora and fauna, members of Sustainable Palm Beach County called the lack of reliable freshwater a chronic problem exacerbated by drought, and now, regularly occurring bouts of summertime algae.

“It took us 10 to 15 years to get us closer to where we should be, then you have a dry spell, and potential algae issues, and the damage grows cumulatively,” said former Palm Beach County Commissioner Karen Marcus, who is president of Sustainable Palm Beach County. “It’s a concern when the water starts slowing down.”

Loxahatchee’s dilemma is man-made. Roads have cut off natural water flows that fed freshwater to the river and canals divert water to keep communities that were built on wetlands from flooding. The permanent opening of the Jupiter Inlet in 1947, and dredging of oyster bars, send a twice-daily fire hose of seawater flooding up the river.

In 1973, the United States Geologic Survey called the Loxahatchee a "river in distress."

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During the dry season, the northwest fork doesn't get enough freshwater moving downstream to keep the saltwater at bay. Over the years, majestic cypress trees native to the waterway have retreated deeper and deeper as brackish water-loving mangroves overran riverbanks.

“Anytime we don’t have adequate water flow in the Loxahatchee it just aggravates the issue with the saltwater,” said Scott Kelly, assistant city administrator for West Palm Beach. “This year, we had a drought during the wet season.”

West Palm Beach had its driest fall in 130 years, and that was coming off a rainy season that saw below normal rainfall. But 2017's Hurricane Irma and record May rainfall fouled Lake Okeechobee with fertilizer-laden runoff that helped grow an algae bloom that eventually seeded the Caloosahatchee and St. Lucie estuaries.

West Palm Beach is especially protective of Grassy Waters Preserve because it supplies the bulk of its drinking water.

Kelly said the canal it closed in May was reopened in November, but it’s unknown when significant amounts of water can be sent to the Loxahatchee River.

“We’re behind the curve because we couldn’t take the water for so long,” Kelly said.

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Work on a permanent solution to feed freshwater to the river has been on and off since at least 2011. It was picked up again in 2016, but recently suspended while the U.S. Army Corps of Engineers asks for more money.

Corps spokesman John Campbell said the request includes a waiver to allow an additional year to complete an “extensive modeling effort.”

“The project enjoys support from our partners at the South Florida Water Management District and from the local community,” Campbell said. “We hope to have updated information in the coming weeks.”

The plan would use the C-18 Canal West to move water from a proposed 8-foot deep above-ground reservoir on the Mecca Farms site to the C-18 Canal and into the river. The district bought the vacant Mecca Farms site, which was once slated for the Scripps Research Institute, from the county in 2013 for $26 million.

“If a Mecca reservoir was full, we would have water to supplement flows to the river,” said Albrey Arrington, executive director of the Loxahatchee River District. “We’re going into the dry season this year in very dry conditions.

But not everyone favors the proposed project.

Sustainable Palm Beach County wants the water to flow naturally over the Mecca site instead of building a holding tank.

“Above-ground reservoirs can also be prone to algae blooms which is why we have been advocating for wetland restoration,” said Lisa Interlandi, executive director of the Everglades Law Center. “The cleanest and best source of water for the river is a restored watershed.”

Kmiller@pbpost.com

@Kmillerweather