Water quality, quantity to be topic at Captiva Island Yacht Club panel discussion
The Captiva Island Yacht Club is holding a free panel discussion for the community next week concerning a topic of concern – water quality and water quantity issues the area is facing.
The panel discussion will be held from 10:30 a.m. to 11:45 a.m. Tuesday, Oct. 24. The discussion will be held at the Captiva Island Yacht Club, 15903 Captiva Drive.
Sanibel-Captiva Conservation Foundation Marine Laboratory Director Eric Milbrandt and Natural Resource Director James Evans are the speakers. Dr. Erhard Joeres, an environmental engineer, will moderate the panel presentation.
“Because of Sanibel’s proximity to the Caloosahatchee, we are at the mouth of the river, which is an estuary. That is where salt water and fresh water meet. Trying to balance the amount of fresh water that comes into the system to maintain a healthy estuary is critical. Our biggest problems are is we get too much water when we don’t need it, and we don’t get enough water when we do need it, which creates a salinity imbalance in the system,” Evans said.
To help the situation, Evans said they would like to implement policy and projects to help restore that balance of salinity in the estuary, which will ultimately make the system more resilient and promote better habitat for fish and wildlife.
With the changes in salinity, water quality issues can arise, affecting nitrogen and phosphorus levels. Those nutrients can drive algae bloom and create problems in the estuary and coastal waters. The color of the water can also be affected, which is more visual when the tides change.
“Our biggest concern right now is the volume of water that are coming from the Caloosahatchee watershed. That watershed is about 865,000 acres. It’s a massive watershed. The other issue we are dealing with is the regulatory discharges from Lake Okeechobee,” Evans said. “It’s the combined impacts from the watershed runoffs from the recent storms, combined with the regulatory discharges from the lake by the Army Corps of Engineers that are really having a devastating impact on our estuaries.”
Lake O, as of Thursday was 17.2 feet, which is in the high management band of the Lake Okeechobee regulation schedule. The lake, should be maintained between 12.5 and 15.5 feet. The inflows, Evans said were at 13,795 cubic feet per second, which is all the inlets.
He said when looking at the entire system, the watershed really extends from Orlando to Shell Point.
“That means the water elevation under the lake schedule is at a point where it could potentially be harmful and we could have a breach and impact communities around Lake Okeechobee if the water levels continue to rise,” he said. “So, the Army Corps of Engineers is trying to discharge out of any outlet that they have. That means the water is going to the east to St. Lucie, it’s going west to the Caloosahatchee and limited amounts going to the south because the water conservation areas are all full.”
To get Lake O down to 15.5 feet, Evans said they are looking to get about 1.7 feet of water.
“For every foot of water in the lake, that equates to about 450,000 acre feet. To put that into perspective, one acre foot, is one acre of land, covered with a foot of water. We have about 765,000 acre of feet of extra water in there just to get to the 15.5 foot level. That is a lot of water and that has to go somewhere,” Evans said.
“From Lake O, they are discharging 7,332 cubic feet per second to the Caloosahatchee,” Evans said last Thursday. “They are discharging 4,619 cubic feet per second to the St. Lucie. For the Calooshatchee that does not include what is coming from the 865,000 acre watershed. When you combine what is coming from the lake and the watershed, our flows are at 10,835 cubic feet per second.”
He said they want to maintain the high flow harm threshold for the estuary based on salinity targets below 2,800 cubic feet per second.
“Those flows are more than three times the high flow harm threshold,” Evans said.
The downfall is residents should expect to see those high numbers for the next couple of months due to the volume of water needed out of the lake. The Calooshatchee is the biggest outlet, resulting in the area most likely seeing the greatest impact.
The silver lining is transition has begun to the dry season, resulting in an eventual water supply demand in the Everglades Agricultural Area, south of Lake O. Evans said during the dry season they draw a lot of water from Lake O for irrigation purposes.
“In a hot year in the dry season more water will evaporate out of the lake. It’s a big surface area in the lake. That’s about 450,000 acres of land. With more heat you will get more evaporation and with drier conditions in South Florida there will be more of an irrigation demand, which will help pull more water out of the system. Unfortunately right now everything is saturated, so everything south of the lake is wet,” Evans said. “They don’t want more water.”
Milbrandt said the water quality and beaches are being affected with the high flows of water being discharged from Lake Okeechobee. He said that will probably continue as people come back this winter, maybe not so much on the western side of Sanibel, but the east side near the Lighthouse.
“We are seeing low oxygen. We are seeing the changing distribution of fish that are able to move. We are seeing invertebrates that are mobile, like blue crabs. The crab fishermen that are usually fishing in Fort Myers, they are fishing now in San Carlos Bay. There has been a big shift in terms of where the estuary is. Normally the salient gradient is from, during a normal wet period, would be from Fort Myers to Punta Rassa. Now it has been displaced down from Shell Point to somewhere off the Estero Island on Fort Myers Beach. It has been shifted in a big way.”
Fortunately things that are mobile will move, but others that are not mobile will tolerate the conditions for as long as they can.
“If you have a stable situation you would get a redistribution of these animals and plants. Because our estuary is naturally connected to this system where they are trying to release water, the species that are here never have a chance to become established. There is constant movement of salinity,” Milbrandt said. “The habitats that are here, like seagrass and oysters are going to be severely degraded, not functioning in a way that they were last year.”
For the past 10 years, SCCF has been collecting data from numerous locations through RECON.
“Each big event like this typically by the next year you see that there is some recovery. When you have subsequent years of high flows, which we have had in 13, 16 and now this year, we have seen the cumulative affects as far as decreasing the density of seagrass,” Milbrandt said. “If we stopped everything and got within our threshold, I’m confident that the estuary would recover perfectly. We will continue to watch and monitor and report what we find to everyone.”
Evans said if it was not for the SCCF Marine Lab they would not have the data to make management recommendations to the South Florida Management District and the Army Corps of Engineers. He said because of RECON it helps them determine what is going on in real time.
“There is not a lot of communities that have that kind of information,” he said. “That has been extremely helpful.”
Evans said with projects still a good few decades off, it’s important to keep dialogues going with local, state and federal policy makers.
“It’s not just an environmental issue. It’s not just a ecological issue and impacts to the Caloosahatchee estuary. It’s an economic issue. It has an impact on our quality of life. It has an impact on our main economic driver on Sanibel, which is tourism. It has an impact on our property values,” he said. “When we get these high discharges and a lot of runoff from the watershed it can actually impact human health. Bacteria levels did spike after the hurricane. Now they are within the good range, which is great. Those have an impact.”
The key to the large flows, Evans said is to get through it together and not favoring any business, or community over another.
“That is really an important component of this,” he said. “
Milbrandt said they have already been out on the water and have seen some of the influences of what they believe are a combination of low light and salinity, as well as an extremely low tide in front of Hurricane Irma. That low tide, Milbrandt said exposed large areas of submerged bottoms that usually are not exposed to air.
“You are seeing a lot of seagrass washing up on the Causeway, in Tarpon Bay and lots of other places,” he said, adding that he hopes the seagrasses are rooted below ground and remain in tact. “Hopefully the leaves are just falling off.”
Milbrandt said it is remarkable how resilient the system is, especially due to the extreme conditions they face.
“Hopefully we can clear up some myths and establish, if there is not already, a more open dialogue with our community leaders. I think they have been awesome. Mayor Ruane has taken a major role in water quality and I think it has made a difference. The science is pretty cut and dry. We will continue to provide the science,” he said.
For more information about the presentation, call the Captiva Yacht Club at (239) 472-4133.