Florida Lake Management Society Annual Conference, Naples, Florida, June 4 – 7, 2007
relatively low compared with those for phosphorus, the implementation of BMPs is less successful in controlling the increase of TN loading from the watershed. The projected future conditions have an 11% increase of TN loading from the current level. Additional reductions of watershed nutrient contributions can be achieved by implementing BMPs to the areas currently without receiving treatment. Implementing BMPs to 25%, 50%, and 75% of the current land uses without BMPs and 100% of future development could reduce nutrient loadings from the projected future levels by 3%, 6%, and 9% for TN and by 6%, 11%, and 17% for TP. Despite implementing BMPs to an extreme level (Future + 75% BMP), the resulting nutrient loadings will still be well above the estimated background loadings under the pristine scenario, which account for only 31% and 32% of the projected future TN and TP levels. To achieve greater nutrient reductions than those in the simulated BMP implementation scenarios, watershed management should focus on implementing nonstructural BMPs (such as better source control and stormwater reuse) to reduce nutrient loading rates from developed areas and using BMP treatment trains to improve nutrient removal efficiencies.
Watershed Loadings (mton/yr)
Figure 1. Comparison of average annual TN and TP loads to Lake Jesup for the six simulated scenarios.
Session 5A – Page 3