Citation:

JARNAGIN, S. AND D. B. JENNINGS. MEASURING HYDROLOGICAL CHANGE DURING EXURBAN DEVELOPMENT: COLLABORATIVE HYDROLOGIC RESEARCH IN THE CLARKSBURG SPECIAL PROTECTION AREA. Presented at USGS Eastern Region Workshop, Herndon, VA, February 08 - 10, 2005.

Impact/Purpose:

The primary objectives of this research are to:

Develop methodologies so that landscape indicator values generated from different sensors on different dates (but in the same areas) are comparable; differences in metric values result from landscape changes and not differences in the sensors;

Quantify relationships between landscape metrics generated from wall-to-wall spatial data and (1) specific parameters related to water resource conditions in different environmental settings across the US, including but not limited to nutrients, sediment, and benthic communities, and (2) multi-species habitat suitability;

Develop and validate multivariate models based on quantification studies;

Develop GIS/model assessment protocols and tools to characterize risk of nutrient and sediment TMDL exceedence;

Complete an initial draft (potentially web based) of a national landscape condition assessment.

This research directly supports long-term goals established in ORDs multiyear plans related to GPRA Goal 2 (Water) and GPRA Goal 4 (Healthy Communities and Ecosystems), although funding for this task comes from Goal 4. Relative to the GRPA Goal 2 multiyear plan, this research is intended to "provide tools to assess and diagnose impairment in aquatic systems and the sources of associated stressors." Relative to the Goal 4 Multiyear Plan this research is intended to (1) provide states and tribes with an ability to assess the condition of waterbodies in a scientifically defensible and representative way, while allowing for aggregation and assessment of trends at multiple scales, (2) assist Federal, State and Local managers in diagnosing the probable cause and forecasting future conditions in a scientifically defensible manner to protect and restore ecosystems, and (3) provide Federal, State and Local managers with a scientifically defensible way to assess current and future ecological conditions, and probable causes of impairments, and a way to evaluate alternative future management scenarios.

Description:

This research project is focused on the Clarksburg Special Protection Area (CSPA) in Montgomery County, Maryland. The CSPA subwatersheds are on the outer edge of the exurban development shockwave expanding outward from the Washington, DC, metropolitan area. The CSPA is an area of rapid development that we expect will be built out within the next five to ten years. The Montgomery County Department of Environmental Protection (DEP) has been monitoring stream biology and chemistry in the area streams and the CSPA involves special best management practices (BMPs) that are designed to limit the impact of development on water resources.

This research is an example of a Federal-Local technology-transfer partnership where innovative technologies are researched at the Federal level and the results made available at a local level for neighborhood solutions. This research is a collaborative effort where local stakeholders are involved setting research goals and Federal agencies are involved offering expertise and capabilities not available at the local level.

The objective of the USEPA research is to correlate the impacts of ongoing development and the mitigating effect of local best management practices (BMPs) on the hydrological, biological, and chemical parameters of the CSPA water resources using a Before-After, Control-Impact (BACI) study design. The BACI design employs both positive and negative controls (stream gauges and monitoring in areas without development and areas developed without the CSP A BMPs) as well as pre- and post development data from areas gauged prior to development within the CSPA. The USEPA is focused on determining the effectiveness of BMP mitigation on streamflow disturbance, channel erosion and stream sedimentation due to impervious surfaces, sub-surface storm sewers and altered landform due to urbanization.

Our primary research activities are to map the development as it occurs; both the anthropogenic surface structures such as roads, buildings, parking lots, and changes in surface topography associated with urbanization and the subsurface storm sewer network; and to monitor the physical, chemical, and biological aspects of the associated water resources as that development happens. Changes in streamflow and biological and chemical parameters of the CSPA water resources (or the lack thereof) will be correlated with development patterns, anthropogenic alterations of the environment, and the BMPs designed to mitigate the impacts of development. The USEPA has funded the placement of five research-grade streamflow gauges and have obtained two LIDAR overflights of the study area (2002 and 2004) that greatly increases the spatial resolution of the topographical analyses possible in the CSPA. These and future LIDAR collections will be used to determine if this technology can be used to map changes in stream morphology associated with development as well as to assist in the hydrological modeling and surface mapping of that development.

Record Details: