HR: 0830h
AN: H21D-04    [Abstracts]
TI: Modeling the Influence of Stormwater from Riparian Development on Small, Groundwater-Dominated Lakes
AU: * McGinley, P M
EM: pmcginle@uwsp.edu
AF: University of Wisconsin-Stevens Point, College of Natural Resources, Stevens Point, WI 54481 United States
AB: Accelerated phosphorus movement from terrestrial to aquatic ecosystems has been linked to deleterious increases in the biological productivity of many lakes. As lakeshores become more intensively developed, there is increasing concern over how this development alters the transfer of phosphorus. Small, groundwater dominated lakes may be particularly vulnerable to this transfer because of their relatively large shoreline/volume ratio, but they are often considered resilient to trophic status change when they have long hydraulic residence times and substantial calcium carbonate precipitation. A multi-disciplinary effort was made to understand the possible impacts of stormwater runoff from riparian development on twenty-two small lakes where water inflow is dominated by direct groundwater seepage. An in-lake phosphorus response model that accounts for phosphorus association and burial with precipitating calcium carbonate was developed and calibrated using the lake set. Nutrient and hydrologic budgets for the study lakes were developed using current and historical land use, historical water quality, recent monitoring, groundwater flow modeling and physical measurements. The calibrated in-lake response model was coupled with a stormwater runoff simulation model using both average annual and extreme precipitation distributions, and a variety of development approaches to estimate phosphorus loads for different development scenarios. The results were used in a sensitivity analysis to identify and communicate the considerations that should accompany efforts to increase development on small, groundwater-dominated lakes.
DE: 1829 Groundwater hydrology
DE: 1845 Limnology
SC: Hydrology [H]
MN: 2005 Joint Assembly