Lake Okeechobee is getting lower during dry season, but how low will it go?

Ever so slightly, ever so slowly, Lake Okeechobee's water level is creeping lower. 

Hundredth of an inch by hundredth of an inch. Which is a lot, considering the massive lake is 730 square miles in size.

The "Liquid Heart of Florida," as it has been called, looks pretty from its shoreline. Blue water. Green grass islands. Vegetation along its shores, lush and thriving. Wildlife and birds are everywhere, going about their business.

As of April 24, the level of Lake Okeechobee measured at 11.36 feet, according to the Army Corps of Engineers. I'll explain the numbers later in this column. 

What signs indicate the lake is shrinking? Well, they're very subtle right now. For instance, the tops of the reef balls are showing underneath the fishing and observation pier at Jaycee Park near the city of Okeechobee on the lake's northern point.

To me, that's always the sign the lake is below the 12-foot mark. It also means a few other things:

• Boaters need to begin to use caution when running the lake. A boat running at high speed could strike a shoal or submerged object, causing damage or injury.
• Three of the small locks between the rim canal and the lake are closed to boat traffic: S-135, J & S Fish Camp; G-36, Henry Creek; and S-127, Buckhead Ridge
• Cross-lake boat traffic on the Okeechobee Waterway needs to use caution as navigation channel depth is at 5.30 feet  
• Water flowing toward the Caloosahatchee River will reach minimal or eventually zero flows

Good things that can happen when it gets low:

• Sunlight reaches the submerged aquatic vegetation
• The enhanced habitat helps provide a healthier nursery for numerous fish species
• There is a decreased chance of harmful discharges toward the estuaries by summer's end 

So what does a lake level of 11.36 feet mean? The number indicates the level of the lake's surface as measured against sea level. It is not an indicator of the lake's depth, which is much shallower. The deepest spot in all of Lake Okeechobee is about 12 feet when the water level is average. Most of its area is shallow enough to wade, that is, if there weren't tens of thousands of alligators living there.

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Does this mean boaters can't fish? Not at all. David Crandall of Okeechobee caught some nice bass earlier this week. I asked him if the low water was a problem. He said boaters do need to be careful.

"Boaters need to idle in toward their spots and idle out to deeper water before getting on plane," Crandall said. "Otherwise, you might have to push your boat off a shoal."

How does the present level stack up? There is a growing concern among several stakeholders about the lake's level. March really fanned those fears when the 16-county area in the South Florida Water Management District received a record low 0.25 inches of rainfall average. That is a full 2.25 inches below the average for the month of March. April has been slightly better, except for the Southwest Florida area of Lee, Collier and Monroe counties, where it still has not rained.

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Here are some Lake Okeechobee figures for comparison:

• 11.36 feet (April 24, 2020)
• 11.45 feet (April 24, 2019)
• 13.24 feet (April 24, 2018)
• 9.82 feet (April 24, 2007)
• 8.82 feet (July 2, 2007, all-time record low)
• 9.64 feet (June 16, 2011, low for the year)
• 13.16 feet (Jan. 1, 2020)

Here is why this matters. Since 2008, the Army Corps of Engineers, which manages the level of Lake Okeechobee, has operated using a document called the Lake Okeechobee Regulation Schedule 2008 (LORS08). It was developed as a result of the catastrophic events after Hurricane Katrina in 2005.

In 1926 and 1928, two hurricanes hit Lake Okeechobee head on. Over 2,800 lives were lost in the flooding in the lakeside communities such as Moore Haven, Port Mayaca, Canal Point, Pahokee and Belle Glade. President Herbert Hoover and Congress authorized the construction of the Herbert Hoover Dike.

It is 143 miles in circumference encircling Lake Okeechobee and was completed in 1933. Prior to 2008, the Army Corps determined the dike needed to be fortified to protect the lakeside communities from flooding in the future.

LORS08 calls for the Corps to manage the lake between a level of 12.5 feet on June 1 and 15.5 feet by Dec. 1 each year. These dates are important because this six-month period is what we Floridians know as hurricane season. 

Is managing a 467,000-acre lake with a 3-foot range of depth doable? Seems so. However, Florida's unpredictable rainfall always throws a wrench in the Corps' plans. For example, Tropical Storm Fay drifted across Central Florida in August 2008 and dumped 24 inches of rain in 24 hours. Lake Okeechobee rose 4 feet in three weeks. Discharges followed.

So the lake being at 11.36 feet is well below the 12.5-foot mark a little more than a month before June 1. That's a good thing if you live on a coast near the St. Lucie River or Caloosahatchee River. Any lake level above that mark means harmful discharges from Lake Okeechobee are coming your way to start the summer. It's why we've endured "Lost Summers" in 2013, 2014, 2015, 2016 and 2018.

What about the toxic algae? In recent years, we have had to factor in toxic cyanobacteria blooms. The great lake has turned a fluorescent green each summer as the tiny single-celled organisms multiply and collect.

Scientists have linked this to neurological diseases such as ALS, Parkinson's, Alzheimer's and more. Research has discovered the algae is found in the air, and can be breathed in by those exposed to it.

There are already signs of the algae beginning to form, as much as a month sooner than in previous years. That can't be good. However, if the Corps does not discharge water from Lake Okeechobee or the C-44 and C-43 canals, the coastal estuaries in Stuart and Fort Myers may be spared this year.

That is, as long as the rainfall amounts are average.

Ed Killer is TCPalm's outdoors writer. Become a valued customer by subscribing to TCPalm. To interact with Ed, friend him on Facebook at Ed Killer, follow him on Twitter @tcpalmekiller or email him at ed.killer@tcpalm.com.