Water Resources Research Act Program

Details for Project ID 2016MD336B

Assessing riparian hydrologic pathways as controls on forested buffer function in the Antietam Creek watershed, western Maryland

Institute: Maryland
Year Established: 2016 Start Date: 2016-04-01 End Date: 2017-03-31
Total Federal Funds: $34,957 Total Non-Federal Funds: $83,193

Principal Investigators: Keith Eshleman

Abstract: The proposed project is a field-based assessment of groundwater-surface water interactions (and nutrient concentrations/loads associated with such interactions) under seasonal baseflow conditions across the Antietam Creek watershed in the R&V province of western Maryland; the study will be implemented at two spatial scales: the synoptic scale (or watershed-scale) and the local scale (or individual reach-scale). We will use synoptic-scale field data collected by the project to develop an explicit map illustrating the influence of groundwater-surface water interactions on nutrient loads across the entire Maryland portion of the basin; by overlaying the map onto a map of existing riparian forest buffer systems (RFBS), we will be able to assess the nutrient removal function of existing plantings (and natural forest buffers) under the specific sampling conditions associated with field data collection. Further, the map will provide useful information for prioritizing future planting by identifying reaches where nutrient removal function could be enhanced through creation of new RFBS. Finally, by instrumenting four specific reaches (all with RFBS, but along Antietam tributaries that span a range of modes of groundwater-surface water interaction—from “gaining” to “losing” reaches) we will be able to test whether our synoptic-scale map is predictive under a broader range of hydrologic conditions (e.g., stormflow conditions) and at the individual reach-scale. We hypothesize that only those RFBS planted along “gaining” reaches are effective with respect to nutrient retention, since the nutrient load associated with positive lateral groundwater discharge to gaining reaches “flows through” RFBS. Along “losing” streams where local groundwater is effectively recharged, nutrient retention by RFBS would presumably be no more effective than planting forests on other portions of a basin (e.g., upland hydrogeologic settings) where groundwater is usually locally recharged. The project builds on recent work in another western Maryland R&V watershed (Murleys Branch) near Flintstone, Maryland where a similar field study was conducted during the summer of 2015 to understand RFBS function. The Murleys Branch project, funded by a Summer Graduate Fellowship from MWRRC to Ms. Stephanie Siemek, included a synoptic-scale study of the entire watershed and a comparative local-scale study to assess groundwater-surface water interactions within two adjacent stream reaches (one with a RFBS and one without).