Computing the Hydrologic Budget for Lake Wapalanne

Diana Flores (Montclair State University), Amber Lutey (Lehigh University), Sara Kelly (California State University, Monterey Bay), & Jonathan Jordan (University of California, Riverside)

Faculty Mentors: Kirk Barrett, Josh Galster & Duke Ophori (Montclair State University)

Between July 13th and August 3rd 2011, a hydrologic budget for Lake Wapalanne, New Jersey, was calculated based on the equation, P ± G + Si – So – ET =ΔS. Precipitation, groundwater, stream inflow and outflow, evapotranspiration, and lake water storage were measured using direct and indirect methods. Seepage meters were installed to measure the groundwater inputs and outputs. The stream discharge and the lake depth converted from pressure sensors were used to find the stream inflow and outflow. A weather station measured precipitation and water loss (evapotranspiration). The water budget model (ΔS = P ± G + Si – So – ET) was used to calculate lake storage based on collected and calculated data. A survey of the perimeter of the lake provided lake storage data in addition to the water budget model. Results indicate that the average total precipitation and evapotranspiration were 0.44 cm/day and 0.4 cm/day respectively. Stream inflow and outflow discharges were 2474 m3/day and 4018 m3/day respectively, or, expressed as an equivalent depth over the lake's area of about 5.4 hectares, 4.6 cm/day and 7.4 cm/day. Groundwater discharge out of the lake was 0.6 cm/day. The calculated change in storage was -50,227m3 and the change in storage from the survey was 2,714 m3. The change in lake storage was minimal. Surface water inflow and outflow are the greatest contributors of lake water storage; however, it is believed that water inflow is underestimated in this analysis and is the source for the majority of the error in the hydrologic budget. These results and methods create a baseline water budget for future efforts to use and expand upon research on climate change by providing Lake Wapalanne as model of lake response to climate change.

  • Presented at the 2012 Spring Meeting of the Northeastern Section of the Geological Society of America (NEGSA) March 20, 2012 in Hartford, CT.