STOPLEAPS.INFO Forest Lake and Communities Coalition - FLACC

Water Quality - Learn About Effects of Aeration

One of the alleged benefits of LEAPS is the project's improvement of Lake Elsinore's water quality as a result of millions of gallons of water moving up and down the hill. While it is true aeration increases oxygen levels and helps prevent temperature-based stratification and low oxygen levels in deeper layers, aeration does close to nothing in the long-term to reduce the natural elements that cause cloudy greenish water: Nitrogen, potassium, and phosphorus from natural and man-made sources including agricultural / yard fertilizer runoff and septic systems are the main food source for micro flora - the tiny plant organisms that give the lake its color.


Studies by government environmental agencies and academic research institutions consistently show Lake Aeration has little to no impact on long-term Phosphorous levels in a shallow lake environment. Lake Elsinore has high phosphorous as a result of its water supply and also because it is not a fully-flowing lake, more like a long-term holding basin with no continuous in/out mechanism to regularly replace its water. Water flows into lake Elsinore and stays there. As lake water evaporates, concentrations of dissolved solids increase, temperatures increase and micro flora blooms occur.


A documented effect of aeration on shallow lakes, according to the experts, is an overall increase in lake temperatures resulting from mixing up of the cooler and warmer layers. Warmer waters combined with high nutrient concentrations can result in algae blooms and cloudy water. If aeration were a silver bullet, Lake Elsinore, which has been aerated for many years now, would look quite different.


Another potential side effect of moving such high volumes of water in and out of the lake is higher turbidity, or cloudiness, from disturbance of lake bottom solids/dissolved solids. If you have ever stepped on and disturbed the bottom in a clear lake or river and saw the resulting cloud of muck destroy visibility, imagine what moving millions of gallons will do to lake clarity over time. In addition, the complete effects of disturbing the Bottom of Lake Elsinore, in terms of what could be released into the water, are unknown.

Below is just a small sampling of studies demonstrating the effects of aeration on lakes - Note the distinction between shallow lakes such as Lake Elsinore, and deep lakes, where water stratification by temperature layers is more pronounced and aeration tends to work better than in shallow bodies of water.