Tri-State Marine Stormwater Wetland


Tri-State Marine Has Installed Progressive Stormwater System To Protect Herring Bay

The South River Federation, a local grass-root environmental organization in Edgewater, MD, partnered with Tri-State Marine, a full-service marine business in Deale that has been locally owned and operated for 50 years, to improve the health of an important waterway in Southern Anne Arundel County.

The project will help improve water quality by treating polluted stormwater runoff before in enters Parkers Creek, which is a tributary of Herring Bay. The Chesapeake Bay Trust has awarded a grant of $164,000 toward this project, which directly affects the Herring Bay watershed that has been identified as a candidate for restoration under the County's Watershed Implementation Plan. This is the first public-private partnership for a stormwater project on commercial property in South Anne Arundel County. Construction began summer of 2017.

A simplified description of the new facility is provided in the Project View exhibit. State-of-the-art "green infrastructure," including swales, forebays, native trees and wetland plants will replace upland area that had been used for parking and storage. Wetland plants will filter sediment and nutrients and provide habitat and food for wildlife. The project will treat runoff from a large "upstream area" that now drains without treatment in to Parker Creek and Herring Bay. 

This project is a great example of public-private partnership to remediate storm water pollution. Tom and Mary Beth Magenau, the principal owners of Tri-State Marine (TSM), believe that a company that depends upon a healthy Chesapeake Bay should contribute to projects that produce meaningful water quality enhancements. Starting in 1999, TSM has funded complex permitting and specific land acquisitions, without which the project would never have been feasible. In addition, during this time period, more than 40 acres on the east side of TSM's  commercial site have been placed in permanent conservation.

Since this project is voluntary and unrelated to ongoing improvements to the TSM facility, the company will receive a fifty percent reduction in stormwater fees under the County Stormwater fee program, highlighting an incentive that is now available to business as well as private landowners. 

The project generated a number of construction jobs in Southern Anne Arundel County and engaged students and community groups in education and outreach to help with planting and monitoring. The Tri-State Marine "stormwater retrofit" will also help the County meet Maryland's 20% impervious restoration target for pollutant reduction.

Sediment is the number one pollutant now effecting water quality in Herring Bay. It suffocates fish spawning grounds and prevents growth of underwater grass, which is a vital provider of oxygen, habitat and filtration. It is estimated that the project will reduce the annual total suspended solids (TSS) load by 11,000 pounds, a reduction of 85% from existing conditions. The improvements  made  in 2017 will filter and cool stormwater as it passes through "terraced wetlands" before entering a culvert pipe that extends southward under Mimosa Cove Road to the Chesapeake Bay.

Topographic conditions have created a uniquely efficient opportunity to improve water quality. The current stormwater flow pattern was established in a State Highway Administration easement in the early 1900's. Created by existing topographic conditions, the natural drainage area consolidates runoff from public roads, existing housing, and commercial areas that have never before benefited from stormwater management. The Tri-State Marine site occupies about 28% of the total drainage area, which is identified in the Project View exhibit.

Tri-State Marine, Inc.: The original corporation was established by Tom and Mary Beth Magenau in 1966 and moved to its present location in 1968. The present Deale site was zoned W2 in the 1960's, intended by the County to create an off-water commercial employment center. This objective has been successful, with approximately 100 people now employed by a diverse group of businesses operating on the site. Tri-State Marine has about 30 employees and is the leasing agent for most of the resident businesses. 

South River Federation has completed more than 77 restoration projects since it was established in 2001. The "TSM stormwater retrofit" is the first significant project that SRF has managed outside the South River watershed, marking a new phase of growth by the Federation as a leading regional provider of restoration services. With holistic approach to improvements in the South River watershed, the Federation utilizes all available tools, including scientific water quality monitoring, rain garden installations, large-scale stream restoration and one-on-one landowner education. Our restoration efforts are locally focused and driven by sound scientific principles. The offices of the Federation are located at 2822 Solomons Island Road, Suite 202, Edgewater, MD 21037. Please visit the SRF website at for further information.