Urban Streams and Stream Restoration
An urban stream is a formerly natural waterway that flows through a heavily populated area. Citizens and industry contribute to urban stream pollution. In many large cities like Baltimore, construction projects in the past have altered the flow and/or course of urban streams to prevent localized flooding. Some of these techniques included lining streambeds with concrete or other hardscape materials, and/or diverting the stream into culverts and storm drains. Thus, many urban streams run underground for at least a portion of their length. These modifications have often resulted in loss of habitat for fish and other species, caused downstream flooding due to alterations of flood plains, and further deteriorated water quality.
The mission of the Surface Water Management Division is to maintain and improve the City’s stormwater collection and conveyance system, stream health and habitat, and protect open waterways. This includes the implementation of the City’s Municipal Separate Storm Sewer System Permit (MS4)*. The Surface Water Management Division provides planning, engineering, and maintenance of the streams and open and closed waterways within the City in an effort to protect the environment and to protect public health and safety. The development of the capital program for stormwater and environmental facilities is the responsibility of the Surface Water Management Division with the assistance of Bureau’s fiscal staff.
Our major goal is the implementation of watershed restoration plans required by the MS4 Permit and in improving the integrity of the storm drain, open channel, and stream systems. Additional goals:
- Complete stormwater collection and conveyance system improvements.
- Complete stream, habitat, and open channel improvements.
- Complete stormwater pollution control facilities.
- Complete watershed restoration plans as required by the permit.
* MS4 Permit – Renewed every 5 years, it sets the legal ground rules for discharges into our waterways.
Watershed planning and plans, under the watershed management program, rely on input from citizens and community partners, especially local watershed associations. Citizen activism helps to protect Baltimore City water resources.
Baltimore City consists of four major watersheds. SWMD staff continually evaluates protection and restoration strategies for the natural resources throughout our watersheds. The City has developed approximately 12 technical watershed plans and studies for the watersheds.
What Is Involved in a Watershed Restoration?
To restore a watershed, there must be a Watershed Plan. This plan is a mandated blueprint for meeting the Clean Water Act and our NPDES MS4 permit. A watershed restoration plan includes:
- Stakeholder participation: a broad-based group brings a breadth of knowledge of the landscape and its history and current condition. Although maps and GIS are wonderful, they cannot replace personal knowledge of an area. Secondly, a broad based group helps season the plan development process with a variety of points of view - a variety that is hard to achieve by City staff alone. This broad base helps incorporate differences and diminishes polarization. Finally, a Steering Committee process plants the seeds for partnerships, shared problem solving and shared resources, all of which are important to watershed rehabilitation and stabilization plan implementation. This has been done in the City’s Gwynns Falls, Herring Run, Lower Stony and Jones Falls Master Plans.
- Selection of locations for restoration projects: These are based on stakeholder input and science. MDE and EPA mandated water quality monitoring by the City’s Surface Water Management Division Pollution Control expert staff shows where the most pollution is located. Thousands of samples from streets, streams, and the Harbor are collected annually, lab tested and verified. This is how we know our surface waters are polluted.
- Securing funding: Restoration funding comes under the City’s Capital Improvement Program. Funding for restoration in the past has come from disparate sources, including State Motor Vehicle Revenue, mitigation money from State agencies including the MD Port Administration, and a myriad of grants including, but not limited to, the MD Department of Natural Resources and Department of the Environment, Corps of Engineers, Chesapeake Bay Trust, Bay Trust Fund, Chesapeake & Atlantic Coastal Bays 2010 Trust Fund, MDE Stormwater Cost-Share Grant and the National Fish and Wildlife Foundation.
- Construction of “Best Management Practices” (BMPs): These include stream restorations, rain gardens, curb bump-outs, bank modifications, in-stream structures, stream bank stabilization, wetland creation, flood control, vegetation planting, and riparian corridor management.
Does Restoration Work? Measuring Success:
The City monitors the effectiveness of the restoration practices as per Part III.H of the NPDES MS4 Permit.
The Stony Run Example
Success from the first Stony Run stream restoration project was documented in an article about the return of frogs published in the Baltimore Sun.
The City has noticed a significant "improvement" in biodiversity at Stony Run since the restoration. American toads were in a mating frenzy in May of 2009 in one new channel pool. Green frogs have been calling during the summer in an excavated spill pond that now contains pickerelweed from plantings and perhaps some self-generation. Crayfish are sighted more frequently.
With birds, the most interesting sightings were Solitary Sandpipers at the same toad pool and on the other side of Wynhurst along the stream channel. The same birds were on several occasions in indicating there was enough aquatic food to sustain an extended stay before heading north. This is the first time sandpipers have been spotted in this portion of the stream. Redwing blackbirds have also moved into the marsh area and bred for the first time.
A May 2009 bird count along Stony Run was exceptional with about 61 species noted between 7:00 a.m. and 10:30 am. While some trees were removed for the restoration, the resulting biodiversity is positive. It seems entirely likely that Barred Owls could be here now because of the restoration.
The great number of wetland plantings and natural generation of wetland plants are truly impressive. DPW is in the midst of determining what species are establishing themselves naturally with the aid of transect plots.