Severn River Summary Report
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SEVERN RIVER Watershed Management Master Plan Final Report Submitted to: Anne Arundel County Office of Environmental and Cultural Resources Watershed Management Program 2662 Riva Road Annapolis, MD 21401-7374 Submitted by: KCI Technologies, Inc. 10 North Park Drive Hunt Valley, MD 21030 In Association With: CH2M Hill 13921 Park Center Road, Suite 600 Herndon, VA 20171 February 2006 ACKNOWLEDGEMENTS The Severn River Watershed Management Plan was prepared by staff from KCI Technologies and CH2M HILL with review from Anne Arundel County personnel. Funding and support was provided by Anne Arundel County. The principal authors were: Bill Frost, PE Project Manager, KCI Tara Ajello, PE Project Manager, CH2M HILL Mike Pieper Senior Environmental Scientist, KCI, Support was provided by: Bill Medina Project Engineer, KCI Nate Drescher GIS Specialist, KCI Andy Hu GIS Programmer, CH2M HILL Mark Kramer GIS Programmer, CH2M HILL Lindsay Nicoll Environmental Scientist, KCI Andrea Poling GIS Specialist, KCI Mike Miller Environmental Scientist, KCI Internal review of the report was provided by: Laurens van der Tak, PE Senior Engineer, CH2M HILL The authors would like to thank the following Anne Arundel County staff for their review, comments and advice through the course of the project: Charlie Abrahamson, Office of Planning and Zoning Ronald Bowen, Department of Public Works Ginger Ellis, Office of Environmental and Cultural Resources Ron Etzel, Department of Public Works (retired) Rick Fisher, Office of Environmental and Cultural Resources Hala Flores, Office of Environmental and Cultural Resources Carolyn Gaulke, Office of Information Technology David Gillum, Office of Information Technology Darryl Hockstra, Department of Public Works Janis Markusic, Office of Environmental and Cultural Resources Rich Olsen, Department of Public Works Chris Phipps, Department of Public Works Merril Plait, Department of Public Works John Scarborough, Department of Public Works (retired) Mary Searing, Office of Environmental and Cultural Resources Chris Victoria, Office of Planning and Zoning Lois Villemaire, Office of Planning and Zoning The members of the Severn River Commission have also contributed time and effort into making the study successful. The authors would like to acknowledge the efforts of Lina Vlavianos, Sally Hornor, and David Mauriello in particular. SEVERN RIVER WATERSHED MANAGEMENT MASTER PLAN FINAL REPORT Executive Summary Introduction Purpose of Watershed Plan As part of the National Pollutant Discharge Elimination System (NPDES) permit for its Municipal Separate Storm Sewer System (MS4), Anne Arundel County has developed a comprehensive Watershed Management Master Plan for the Severn River. The estuarine part of the River is currently on the 303(d) list for nutrients, sediment and bacteria. As a tributary to the Chesapeake Bay, the Severn River is also facing issues that are affecting aquatic resources Bay-wide. The Watershed Management Master Plan has been developed to characterize the watershed’s baseline conditions and resources, assess existing and potential concerns, and propose restoration and preservation improvements with a systematic watershed perspective. Phased Approach to the Scope Due to the extensive scope of the study, the Severn River Watershed Management Plan was undertaken in a series of multi-year phases. In Phase I, the existing environmental studies and GIS coverages for the watershed were assessed. Initial public involvement activities were also performed during this phase. This was the basis for the work done in Phase II, which included a characterization of the current condition of the watershed. Phase III focused on forecasting future conditions, identifying and prioritizing problem areas, and developing a variety of management alternatives. Phase IV concentrated on completing additional more detailed stream assessments and modeling and on summarizing all the work of the project. Public Involvement During Phase I, two public stakeholder workshops and a survey distributed to over 3,500 residents of the Severn River watershed were used to identify public environmental concerns and problems within the watershed, identify data sources that can help with various elements of the Phase II analysis, and identify additional stakeholders to participate in the project. The first public stakeholder workshop on May 3, 2001 featured a presentation on the history of development in the watershed and various aspects of the watershed master planning process. Participants at this meeting identified overall watershed issues and concerns and identified specific problems within the watershed. The second public stakeholder workshop on May 17, 2001 included a summary of the issues heard from the stakeholders at that previous meeting. Workshop participants prioritized particular streams that they would like to see studied in detail. Workshop participants identified and then prioritized a list of pollutants of concern that would be potentially modeled later on in the project. Current Watershed Condition Environmental Setting The Severn River watershed is located within the Coastal Plain physiographic province, which is geologically the youngest in the state. The Coastal Plain is made up of unconsolidated sedimentary deposits eroded by streams flowing from the adjacent Piedmont Province. The topography within the watershed ranges from nearly level to very steep. Steep slopes border the headwater tributaries and downstream floodplains along the northern and southern shoreline of the Severn River. Elevations range from sea level, along the shores of the Chesapeake Bay, to 300 feet. ES - 1 SEVERN RIVER WATERSHED MANAGEMENT MASTER PLAN FINAL REPORT The geology within the watershed is dominated by sand, gravel, silt, and clay of the Cretaceous age. Within the Severn River watershed lie four geologic formations that are hydrologically characterized as aquifers. These formations consist of the Aquia, Magothy, Patapsco-Raritan, and Patuxent Formations, the last two of which are the most heavily used groundwater sources in Maryland. Unique Ecology In 1971, the Severn River was designated as one of Maryland’s Scenic Rivers. Many unique and ecologically important natural features can be found within the borders of its watershed. Within the state of Maryland, Anne Arundel County possesses the highest quantity of freshwater bogs, which qualify as wetlands of special state concern. Bogs within the Severn River Watershed include Arden Bog, Arlington Echo, Cypress Creek, Lakewood, Carrollton, Forked Creek and Sullivan’s Cove. These areas are important as they serve as water filters, improving water quality within the watershed, and creating habitat for rare, threatened and endangered flora and fauna. Jabez Branch, the largest tributary to Severn Run, is the only Coastal Plain stream that supports a naturally reproducing population of brook trout. Jabez Branch has a series of springs and dense forest cover that provide the cool water necessary for brook trout reproduction. Land Use and Development Land use in the watershed is diverse. Portions are highly developed, containing the City of Annapolis, shopping centers, subdivisions, and industrial parks. The free-flowing section of Severn Run, however, is a Natural Resource Area managed by Maryland Department of Natural Resources (MDNR). Many of the south shore watersheds remain forested. The single most dominant land use is single family residential, at all densities, at 38%. Forest is next, at 32%. When the 6% of open space maintained in turf is added to the forested areas, there is an equal amount of residential and vegetated land use. Fifteen percent of the watershed is taken up with denser land uses: commercial and industrial property and the City of Annapolis. Other than the watersheds which drain the City of Annapolis (College Creek, Weems Creek, Spa Creek, and Back Creek), the most densely developed tributaries are Woolchurch Cove (50% impervious), Picture Spring Branch (33%), Pointfield Branch (32%), Bear Branch (30%), and Carr Creek (28%). These subwatersheds drain some parts of Odenton, the commercial areas along I-97, and the Naval Surface Warfare Center. Sewered/Unsewered Areas Twenty-six percent of the watershed is currently served by sanitary sewer systems. An additional 21% is planned to receive sewer service at some time in the future. This leaves over half of the watershed remaining with on-site sewage systems. Most of these areas are on the south shore, which is currently undeveloped or zoned for low-density residential development. Stream Assessment A total of 152 miles of stream were assessed during the stream walk portion of the Watershed Study. During this assessment the stream flow type was assigned, habitat assessments were conducted, a geomorphological assessment was completed and infrastructure features were inventoried and rated based on their impact on the stream’s overall health. Following the stream walk a biological assessment was completed throughout the watershed at 63 sites and a Rosgen Level II classification was completed at 95 sites. Stream Type Perennial streams are most abundant with 89.37 miles making up 58.8% of the total for the entire Watershed. Ephemeral streams comprise 19.5% of the channels. ES - 2 SEVERN RIVER WATERSHED MANAGEMENT MASTER PLAN FINAL REPORT Geomorphology Geomorphic assessment and Rosgen classification was conducted on 92.63 miles of the 152 total miles of streams with 381 separate reaches and cross-sections conducted throughout the Watershed.