Watershed Restoration uses state-of-the-art techniques to reduce sediment, nutrients and pollution to the County’s streams and waterways.
The program structure provides a comprehensive framework of protection and restoration of the County’s natural resources. Projects are prioritized in part based on opportunities identified in watershed management plans. Project funding is supported primarily by County General Obligation Bonds and supplemented by State grant funds from the Maryland Departments of the Environment and Natural Resources and with grants from the Chesapeake Bay Trust.
Stream Restoration and Stabilization integrates natural channel design techniques to enhance ecological function of Baltimore County’s streams and rivers.
Baltimore County has a nationally recognized program for implementing stream restoration and stabilization projects. The goal is to improve water quality and ecological function by:
- Calculating the appropriate channel dimensions to maintain base flow, manage storm flows, and have appropriate sediment movement
- Creating appropriate bed features (riffles and pools) and plan form (shape of the channel within the stream valley) to provide important biochemical exchanges, habitat and energy dissipation
- Stabilizing stream banks to reduce sediment input to receiving waters
- Creating or enhancing the vegetative buffer to reduce nutrient pollution and provide habitat
- Using natural, native materials such as rock, logs and plants to recreate a stable, functional stream system
- Sustaining long-term, natural function and stability by replacing traditional engineered channels which negatively impact ecological function and require periodic maintenance or replacement
Baltimore County strives to ensure that the projects consists of restored, ecologically functional, self-maintaining and aesthetically pleasing stream systems. CPO conducts monitoring of restoration sites to ensure that the project is performing according to design intent.
CPO are selected based on a systematic assessment of the severity of degradation, the achievable goals for each site and the overall benefit to the watershed. CPO utilizes watershed plans, technical assessments and a stream complaint database to identify and prioritize potential projects.
Issues Due to Urbanization
Land use changes, including urbanization, have interrupted the natural, beneficial processes of stream systems. These changes impair the ecological function of Baltimore County’s waterways and ultimately the Chesapeake Bay.
Increased impervious area
Pavement, roofs and other structures resulting from development
Lack of riparian buffer
Floodplain encroachment to maximize development
Piping, channelization and armoring of streams
Rerouting or removal of open streams to maximize development
Infrastructure encroachment within floodplains
Flooding and damage to public and private property
Increased pollutant and sediment loads
Impaired water quality and aquatic habitat
Uses hard (rock jetties and breakwaters) and soft (biologs and vegetation) engineering techniques to reduce erosion and improve ecological function, water quality and habitats along the County’s tidal waterways and on public property. Shoreline projects are identified through comprehensive watershed planning efforts. Project components can include breakwaters, sills, groins, stone revetments and tidal and nontidal plantings.
Shoreline enhancement projects aim to restore eroded shorelines. Causes and impacts of shoreline erosion include:
Living Shoreline Approach
Living shoreline projects protect shorelines from erosion while incorporating nonstructural project design elements. A typical hybrid living shoreline project will consist of low profile stone sills or breakwaters engineered to dissipate wave energy. The area landward of the structures is turned into a shallow wetland area with sand fill planted with native wetland plant species that provide valuable ecosystem benefits. Over five miles of County shoreline have been protected and enhanced and significant acres of wetland have been created, resulting in a reduction in sediment and nutrients entering and impairing local waterways.
Watershed Restoration identifies and implements stormwater retrofit projects to:
- Address unmanaged runoff from precipitation
- Update and improve older stormwater management facilities (conversions)
- Installs new treatment devices
- Improve the water quality of the County waterway
Projects involve the installation of best management practices (BMPs) to store and treat stormwater runoff, particularly in communities built prior to stormwater management requirements.
Types of Stormwater Facilities and Retrofits
These facilities and retrofits retain, and in some cases, filter stormwater to lessen the quantity of water that is entering the stream at one time. The first inch of rainfall is most likely to be carrying pollutants washed from the streets, parking lots and rooftops (impervious surfaces). These stormwater facilities and retrofits ensure that this polluted runoff is allowed to soak into the ground to filter pollutants before they reach streams and tidal waters. Conversion projects have enhanced and created acres of vegetated areas which treat runoff from impervious surfaces resulting in reduction in pollutants, sediment and nutrients entering and impairing local waterways.
Underground Water Quality Device
Underground device connected to a storm drain pipe
Online, Beginning or End of Pipe Improvements
Baltimore County has the most extensive SAV program in Maryland. Many County creeks have an abundance of SAVS, which grow in shallow water areas and which have increased in County waterways in terms of presence, density and species diversity. SAVs are monitored and documented annually as an indicator of the water quality in Baltimore County’s tidal waterways. Since 1989, SAV data has been collected for analyzing and mapping growth trends for all creeks (30 waterways) where the County maintains a navigation channel. SAV data is included in the annual report Distribution of Submerged Aquatic Vegetation in the Chesapeake Bay and Coastal Bays.
SAVs provide numerous environmental benefits including:
- Food and habitat for birds, fish, crabs and other aquatic species
- Water quality and clarity improvements through filtering pollutants and uptake of nutrients
- Shoreline protection by dissipating wave energy and preventing erosion
The Waterway Dredging program maintains navigable passage for Baltimore County's recreational boaters. This shoreline stabilization project uses breakwater structures as well as vegetation. Dredging projects are designed and constructed to restore historic access for recreational and commercial boats to County waterways. CPO oversees each step of dredging projects including bathymetry surveys, design, permitting, construction of main channels and assistance with individual spur channels that connect to the main channel. Aids to navigation buoys marking dredge channels are deployed on a seasonal basis in 17 County waterways.
CPO has completed dredging projects in 25 waterways.
- Bird River
- Breezy Point Cove
- Browns Cove
- Chestnut Cove
- Chink Creek
- Galloway Creek
- Goose Harbor
- Greenhill Cove
- Greyhound Cove
- Frog Mortar Creek
- Hopkins Creek
- Jones Creek
- Lynch Cove
- Lynch Point Cove
- Norman Creek
- Middle River
- Muddy Gut
- North Point Creek
- Pleasure Island “The Cut”
- Railroad Creek
- Schoolhouse Cove
- Shallow Creek
- Seneca Creek
- Sue Creek
- Tabasco Cove
- Improvements in water quality often improves in a dredged waterway due to the reduction of harmful prop dredging.
- Increased water quality
- Increased water clarity
- Increased growth density, growth area and species diversity of Submerged Aquatic Vegetation (SAV)
- Increased SAV leads to improved water quality and aquatic habitat
- Improved boater safety
- enhanced waterfront property value
Baltimore County has a nationally recognized watershed improvement program for implementing stream restoration, shoreline enhancement and stabilization, reforestation, stormwater runoff and best management practice (BMP) projects. Featured below are before-and-after pictures of recently completed projects. To reveal more of the before or after images below, place your cursor on the white line between the images and drag either left or right.
This project was selected based on the goal of reducing sediment and nutrients from entering the Loch Raven Reservoir, severity of stream erosion, and the opportunity to install and improve streamside habitat. Stream banks were graded to a stable slope and armored at critical locations. A vegetated buffer was created with a variety of native plants to help stabilize the stream and improve riparian function and habitat.
This project improves water quality to Back River and the Chesapeake Bay by using structural and non-structural erosion control shoreline enhancement techniques. A series of stone breakwaters and marsh creation reduce nutrient and sediment loads as well as provide ecological uplift with improved tidal shallow water habitat and forested buffer.
General John Stricker Middle School
This urban tree planting project was part of a County-wide effort to plant nearly 1,000 shade trees to increase the County’s urban tree canopy and lower long-term costs for heating and cooling at County school and government buildings. These trees will provide other environmental benefits, including intercepting nearly 144 million gallons of stormwater over 30 years.
Lower Spring Branch
A concrete drainage channel that was installed in the 1960s was beginning to deteriorate. The concrete channel ended abruptly causing severe erosion to adjacent streambanks. The concrete was removed and replaced with native materials using natural channel design techniques to adequately dissipate energy and improve ecological function of the waterway.
This reforestation project converts 12 acres of an abandoned golf course to native oak canopy. As they grow, these trees provide high-quality wildlife habitat and help intercept and treat stormwater, reduce erosion and sediment, improve air quality, and shade streams.
Upper Gwynns Falls
One of five stormwater facility improvement projects in the Gwynns Falls watershed that was converted from runoff quantity control to water quality. Water quality is improved by increasing the time stormwater spends at the facility, allowing nutrients to be absorbed and sediment to settle. This facility was converted to extend the detention of storm water runoff in the pond by constructing forebays, shallow marsh wetland and micropools, and creating a sinuous water channel. Stormwater discharged from the facility has less nutrients and sediment than when it entered.