Watershed Profile: Susquehanna River near Rockville, PA

Provisional Data Graph Results Zoom to Map
 Data Sources Readme
Watershed Overview
The Susquehanna River begins at the outflow of Otsego Lake in Cooperstown, NY. The River flows 444 miles through New York, Pennsylvania and Maryland, before reaching its confluence with the Chesapeake Bay in Havre de Grace, MD. The monitoring station is in the Lower Susquehanna Subbasin near Rockville, PA. The station is downstream of the confluence with the Juniata River, but due to the lack of river mixing and location of the station on the left bank, its water quality is highly influenced by the mainstem.
Drainage Characteristics
  • Drainage Area (square miles): 23557.62
  • Total Stream Length (miles): 42747.00
  • Average Annual Flow at Station (NHD) (cfs): 36002.00
  • Population (2010): 2381396
Stream Classifications (Pennsylvania)
Designation Miles
Exceptional Value 1992.46
High-Quality Cold Water Fisheries 9311.20
High-Quality Trout Stocked Fisheries 79.30
Trout Stocked Fisheries 2426.92
Warm Water Fisheries 5657.97
Total 19467.85
Stream Classifications (New York)
Classification Use Miles
Class A Drinking Water Source 154.70
Class A (T) Drinking Water Source With Trout Population 33.94
Class A (TS) Drinking Water Source With Trout Spawning 24.49
Class AA Drinking Water Source 31.09
Class AA (T) Drinking Water Source With Trout Population 7.13
Class AA (TS) Drinking Water Source With Trout Spawning 3.08
Class B Contact Recreation (Not Drinking Water Source) 369.04
Class B (T) Contact Recreation With Trout Population 53.09
Class C Support Fisheries (Non-Contact) 7630.30
Class C (T) Support Fisheries, Non-Contact With Trout Population 1990.31
Class C (TS) Support Fisheries, Non-Contact With Trout Spawning 884.85
Class D Fishing, But Does Not Support Fish Propagation 8.98
Exempt Exempt 0.03
Total 11191.03
  • Land Use
  • Description Percentage
    Water 0.93
    Developed Open Space 4.85
    Low Urban 1.80
    Medium Urban 0.90
    High Urban 0.33
    Barren 0.28
    Deciduous Forest 47.18
    Coniferous Forest 2.84
    Mixed Forest 16.43
    Shrub Scrub 0.52
    Grassland Herbaceous 0.73
    Pasture/Hay 14.80
    Cropland 6.43
    Wetlands 1.99

  • Natural Gas
  • Natural Gas Pads 1929
  • Natural Gas Water Withdrawals 109

  • Public Water Supply Withdrawals
  • Groundwater 4120
  • Surface Water 201

NPDES Discharges
Description Count
Concentrated Animal Feeding Operation 120
Mining/Quarry 605
Stormwater 953
Wastewater Treatment Plant/Sewage Treatment Plant 451
Other 943

Stream Impairments
Source Category Miles
Acid Mine Drainage Aquatic Life 1818.30
Animal Feeding Operations Aquatic Life 7.30
Atmospheric Deposition Aquatic Life 428.50
Channel Erosion/Incision from Upstream Hydromodifications Aquatic Life 17.30
Channelization Aquatic Life 50.20
Coal Mining Aquatic Life 5.20
Combined Sewer Overflows Aquatic Life 14.20
Construction Aquatic Life 9.70
Crop Production Aquatic Life 187.90
Dam or Impoundment Aquatic Life 42.90
Erosion from Derelict Land Aquatic Life 17.40
Forest Roads Aquatic Life 1.90
Golf Courses Aquatic Life 11.30
Grazing in Riparian Zones Aquatic Life 180.20
Habitat Modification Aquatic Life 129.80
Highway/Road/Bridge Runoff Aquatic Life 250.80
Highways, Roads, Bridges Construction Aquatic Life 3.90
Impacts from Hydrostructure Flow Regulation Aquatic Life 21.20
Impervious Surface/Parking Lot Runoff Aquatic Life 23.10
Industrial Point Source Aquatic Life 32.70
Landfills Aquatic Life 1.80
Municipal Point Source Aquatic Life 34.50
Natural Sources Aquatic Life 14.00
On-Site Treatment Systems Aquatic Life 25.70
Removal of Vegetation Aquatic Life 94.00
Rural (Residential) Aquatic Life 127.40
Silviculture Aquatic Life 6.40
Site Clearance Aquatic Life 5.70
Source Unknown Aquatic Life 107.10
Streambank Modifications Aquatic Life 7.10
Surface Mining Aquatic Life 4.20
Urban Runoff/Storm Sewers Aquatic Life 181.00
Atmospheric Deposition Fish Consumption 693.70
Source Unknown Fish Consumption 519.50
Acid Mine Drainage Potable Water Supply 85.60
Source Unknown Potable Water Supply 1.80
Combined Sewer Overflows Recreational 11.70
Grazing in Riparian Zones Recreational 6.70
On-Site Treatment Systems Recreational 54.30
Rural (Residential) Recreational 188.20
Source Unknown Recreational 2846.60
Urban Runoff/Storm Sewers Recreational 43.50
Underlying Geology
Rock Type Percentage
Dolomite 1.40
Limestone 3.58
Quartzite 1.73
Sandstone 40.33
Shale 52.96
Map
Recent Results
Sample Time 4/24/2025 2:00:00 AM
Temperature  (C) 18.63
Specific Conductivity  (mS/cm)
PH 7.98
Turbidity  (NTU+) 9.88
Dissolved Oxygen  (mg/L) 0
Dissolved Oxygen (last month of readings)
pH (last month of readings)
Specific Conductivity (last month of readings)
Temperature (last month of readings)
Turbidity (last month of readings)