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Participants learn about Caloosahatchee with Sanibel Sea School

By Staff | Nov 1, 2017

Sanibel Sea School Executive Director Dr. Bruce Neill shares information about the river’s oxbows. MEGHAN MCCOY

A half a dozen Sanibel residents braced the cooler temperatures last Wednesday morning to learn about the Caloosahatchee oxbows aboard the Sanibel Sea School’s donated pontoon boat.

Sanibel Sea School Executive Director Dr. Bruce Neill led the boat based class from the Alva Boat Ramp to share knowledge about the Caloosahatchee, while individuals enjoyed the scenery.

Neill said the Kissimmee River, which feeds into Lake Okeechobee, starts around the Orlando International Airport.

“Our watershed really is massive. It starts in Orlando and all of that in Orlando from the east coast to about two-thirds of the way towards the western part of the state goes into the Kissimmee River Basin,” he said, adding that the Kissimmee River had oxbows, taking the water a long time to travel through to Lake O. “In the early 1900s we decided we have all of this terrible useless swamp land and we need money. Why don’t we convert, and reclaim that swamp land and get agriculture to come here. So, we built a dike at the end of Lake Okeechobee.”

Neill said the bottom of the lake already had a little natural dike, so it held water behind.

One of the oxbows located within the Caloosahatchee River. MEGHAN MCCOY

“It also seeped south and was the head water for the Everglades,” he said. “Ordinarily most of the water that came from Orlando south eventually went into the Florida Bay. The Florida Bay is the water behind the Florida Keys.”

The Everglades, Neill said in reality is slow moving river. A dam, he said was built and dried up the area just south of Lake Okeechobee.

“We sold that land to agriculture and the sugar industry bought it,” Neill said. “It cut off water flow to the Everglades. We also recognized at that same time we built I-75 and US 41. We didn’t build them in a suspended way. We came and added fill, so we created three dams – one at the bottom of Lake Okeechobee, one at 1-75 and the other at US 41 to stop the flow into the Everglades. All that water still has to go somewhere.”

Simultaneously, a tiny trickle of a stream was recognized, the Caloosahatchee that flows kind of close to Lake O.

“We can increase interstate transportation by dredging out that little river, the Caloosahatchee and connecting it to Lake Okeechobee, and connecting it to the Atlantic. Now ships don’t have to cut around the Florida Keys,” Neill said.

Neill said when there is no fresh water releases during the dry season, it becomes too saline to support the communities that are along the bottom.

“We need to be able to regulate flows, so we don’t have so much fresh water into our estuary that it kills our estuary. We do need fresh water to regulate the salinity during the dry season,” he said.

As Neill discussed the salt water tongue, which is always along the bottom of the water due to its density, the boat floated within an oxbow of the river.

“One of the components that we deal with significantly is residence time,” he said. “Residence time is how many time units -minutes, hours, days, months, weeks – does a molecule of water stay in a place.”

When thinking about residence time in the river, Neill asked how long does it take a molecule of water to come from Lake Okeechobee into the Gulf of Mexico.

“If you are going in an s shape, it takes you a long time,” he said. “In terms of nature and particularly water, all of these water molecules have mixed in them nutrients. The longer we can have water stay in a river, the more likely it is to be used by vegetation along the river and then come to the estuary relatively nutrient free. When we convert from oxbows into channels we really change the amount of nutrients in the water.”

He said rather than changing the amount of water, they changed the amount of time it took for the water to flow through the river.

“We greatly increased the flow rate and decreased the residence time,” Neill said. “Now we are having to go backwards. They have done very good oxbow restoration in the Kissimmee River.”

The best solution, he said seems to be pretty unified among environmentalist. The best solution, Neill said seems to be to create four reservoirs at the points of the lake – east, west, south and east to regulate flows.

In addition to learning about the oxbows, Neill also pointed out a plethora of vegetation and birds found along the river.

For more information about the Sanibel Sea School, visit www.sanibelseaschool.org.