Can Lake Istokpoga end up like Lake Okeechobee?
by Bill Dwinell and Paul Gray
At our February meeting, Dr. Paul Gray made a wonderful presentation that spelled out some things we need to be concerned about with Lake Istokpoga. I transformed his presentation into this article, with some editing help from Paul.
Lake Okeechobee has suffered from many stresses that culminated in the 1990s as many problems, including algae blooms, loss of "clean-water" bugs and replacement with "pollution tolerant" bugs, 90% submerged plant loss, exotic plant growth, spreading cattails, loss of larval fish, loss of wading birds, loss of waterfowl, loss of snail kites and alligators with unusual hormones. The reasons for these problems were numerous, but the most important causes of the problems are just two things: water level mismanagement and nutrient pollution. These two factors lead to almost all the other problems.
Nutrient pollution seems to be the worse. The level of phosphorus in Lake Okeechobee has approximately tripled since the early 1960s, and this was in spite of four, government-implemented, nutrient control programs. Lots of hoopla but little positive results were achieved. There are many sources of phosphorus entering Lake Okeechobee, the worse being fertilizer which accounts for 73% with an estimated 5,400 metric tons spread in the watershed per year.
One of the key things to note here is that a lake will appear to absorb the phosphorus until it becomes saturated. It is like a dry sponge. For a while you can drip water onto a dry sponge and it will absorb every single drop. Once the sponge becomes saturated, every extra drop will run out. Once the plants and soils in a lake absorb all the
phosphorus they can (like a sponge absorbing water), the rest tends to remain in the water column and cause problems, including algae blooms that can kill fish and threaten animal health, turbidity that can shade out aquatic plant life, and runoff that pollutes downstream water bodies. The nutrient programs, like SWIM (Surface Water Improvement Management), that have been in place for Lake Okeechobee had incorrectly assumed the lake could continue to absorb the large amount of phosphorus being loaded into it annually but they were wrong—the "sponge" was saturated. Now, Lake Okeechobee is in its worst condition ever.
The phosphorus laden mud in the center of Lake Okeechobee is estimated to contain more than 30,000 tons of phosphorus, which is so much, that even if we stopped all phosphorus inflows today, the lake would remain polluted for decades or more. The muck covers a huge area and is as much as three feet thick. It is also estimated that it may take $1 Billion to remove it, if they can figure out how.
What does all this mean as far as Lake Istokpoga is concerned? Well, the outflow of phosphorus, measured at the S-68 structure was 30 ppb (parts per billion) 1990 to 1994, or about 7.1 tons per year that were going down stream. In 1995 to 1999 it was 60 ppb or 27.3 tons of phosphorus. The outflows have roughly doubled in phosphorus concentrations in the last ten years. Is Istokpoga already saturated? One must wonder where the phosphorus is coming from? Is Istokpoga’s mud core growing? What caused this increase?
The Lake Okeechobee legislation that Senator Pruitt sponsored last year calls for an assessment of the phosphorus sources from the Lake Istokpoga Basin, to be completed by
July 1, 2003, but the legislation had no money attached for this and the current status is "no work underway due to lack of funding and resources". Friends of Istokpoga plans to contact the South Florida Water Management District (SFWMD), and Senators Pruitt and Laurent regarding this and request their support for funding it this year.
Lake Okeechobee also is considered a water supply resource by SFWMD, as is Lake Istokpoga. Clearly Lake Okeechobee is such a resource, but it isn’t so clear that Lake Istokpoga should be. The record low levels in Lake Okeechobee this year are only partly due to the drought, and partly due to the irrigators and cities pumping water out of the Lake, in spite of its harmfully-low levels. Should Istokpoga be allowed to be pumped ever-lower during droughts like this? Friends of Istokpoga Lake Association, Inc. fought this for two years, but because there are high costs associated with alternative solutions, SFWMD has elected to ignore our recommendations and consider Lake Istokpoga as a water supply source for the Istokpoga Basin, since it is "free water" as far as they are concerned, in spite of any environmental impacts that might result. By "high costs" they mean that pumping well water costs more, and that building water storage reservoirs on agricultural properties costs more, and installing back-pumps costs more. The growers, and SFWMD would rather not spend their money for their water, they prefer Istokpoga water because it is "free."
During a year with normal rainfall, this is not currently a problem, with outflows of approximately 200,000 acre feet, and demand at only 172,091. The problem arises when we enter drought conditions, or add more users. During a 10-year drought, demand increases to about 204,865 acre feet with significantly less out flows. The deficit is estimated to be at least 64,937 acre feet. While this deficit will be satisfied partially by back-pumping into the lower basin from Lake Okeechobee, the remainder must come from Lake Istokpoga. This will result in withdrawals below the minimum levels set by the current regulation schedule. On top of this, there is an estimated 41,000 acres increase of irrigated crops in Highlands County expected by 2020. This is made up of big citrus groves, vegetable farms, and sugar plantations moving to Highlands County for our water. They will apply for an allocation and once it is granted it will give them a "right" to Istokpoga’s water. Do you think someone should have the right to build a NEW development (agricultural or urban) in a spot that does not have enough water supply for their development, and then be allowed to suck water out of our lake?
Some action items we must keep our eyes on are the Lake Istokpoga Regulation Schedule (how they plan to control lake water levels), the Istokpoga Basin Phosphorus evaluation (where, and how much, pollution), the evaluation of Minimum Levels (MFL) criteria (what is the lowest they will let the lake get), any relaxation of the current moratorium on new Consumptive Use Permits, and the revised operational plan for Lake Istokpoga. Lake Okeechobee’s problems came about because our government agencies have not managed the Lake for its own health. Let’s not let them do this to our Lake Istokpoga.