Watershed Restoration

Watershed Restoration uses state-of-the-art techniques to reduce sediment, nutrients and pollution to the County’s streams and waterways.

PROGRAMS

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. Watershed Restoration staff conduct monitoring of restoration sites to ensure that the projects are performing according to design intent.

ADAPTIVE APPROACH

Stream restoration projects 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. Watershed Restoration identifies and prioritizes potential projects utilizing watershed plans, technical assessments and a stream complaint database. 

STREAM RESTORATION VIDEOS

Learn more about stream restoration by viewing our short documentaries:

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.

Problems Causes Impacts
Increased impervious area Pavement, roofs and other structures resulting from development
  • Decreased base flow
  • Increased volume or velocity during storms
Lack of riparian buffer Floodplain encroachment to maximize development
  • Destabilization of stream banks or bed
  • Erosion
  • Increased water temps
  • Loss of habitat
Piping, channelization and armoring of streams Rerouting or removal of open streams to maximize development
  • Loss of groundwater recharge, habitat, pollutant removal
  • Increase in storm flows
Infrastructure encroachment within floodplains
  • Road crossings
  • Storm drain connections
 Flooding and damage to public and private property
Increased pollutant and sediment loads
  • Yard chemical and agricultural treatments
  • oil spills
  • sediment erosion
  • trash
 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 EROSION

Shoreline enhancement projects aim to restore eroded shorelines. Causes and impacts of shoreline erosion include:

Causes Impacts
  • Land use changes and disturbances
  • Boat wake and wave energy
  • Weather and climate events
  • Lack of vegetative buffer along shoreline
  • Loss of land and property
  • Loss of trees, aquatic vegetation and habitat
  • Sediment and nutrient loading
  • Impaired water quality

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.

Type Typical Features Benefits
Stormwater Pond
  • Impoundment pond to slow, retain and filter water
  • Wetland plants
  • Slows stormwater allowing infiltration
  • Allows sediment to settle out
  • Reduces flooding
  • Improves water quality and nutrient uptake
Bio-Retention Facility
  • Vegetated cells and areas
  • Rain gardens
  • Planted marshes and wetlands
  • Absorbs and filters water
  • Creates habitat
  • Helps reduce flooding
  • Aesthetic appeal
  • Improves nutrient uptake
Underground Water Quality Device Underground device connected to a storm drain pipe
  • Filters oil, grit, trash and sediment from stormwater
  • Storm drain outfall protection 
Online, Beginning or End of Pipe Improvements
  • Micro pools
  • Forebays
  • Gabion sandwiches
  • Sand filters
  • Rain barrels
  • Captures and retains water
  • Dissipates energy of water
  • Reduces erosion
  • Filters water

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.

BENEFITS

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. 

HIGHLIGHTS

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

BENEFITS

  • 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