Upper Patuxent Watershed


spacerFacebook LinkedIn Twitter

Success Story

Upper Patuxent Watershed Assessment

The Upper Patuxent River watershed in Anne Arundel County, MD, flows into the Chesapeake Bay. The Upper Patuxent basin drains approximately 22,500 acres, is subdivided into 19 subwatersheds, and contains approximately 130 miles of perennial stream reaches.


As part of its NPDES municipal separate storm sewer system permit, the County was required to perform an assessment of land-use conditions within the Upper Patuxent watershed. The goal was to help it determine where to focus resources to maintain waterbodies in good condition, and also where mitigation of potential problems is necessary to improve the overall watershed health and quality.


LimnoTech’s role in this process was to provide accurate, up-to-date data and information for the 19 subwatersheds within the river basin. The County then incorporated these data into a suite of models to perform an in-depth assessment of the watershed. While collecting the major data elements, LimnoTech performed physical habitat condition assessments, base flow sampling, stormwater facility mapping, and Rosgen Level I and II classifications for stream reaches.

In addition, LimnoTech collected data on habitat parameters and channel stability that will enable the County to expand its analyses in the future.


Upon project completion, LimnoTech will provide the County with final GIS and database deliverables to be used for additional modeling, ranking and decision-making for the watershed. During the project, we have provided feedback to the County regarding the data-collection and assessment process, streamlining several elements. We will have the opportunity to provide additional feedback and suggestions during the final technical peer review process.