Watershed Profile: Susquehanna River near Rockville, PA

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): 23,557.62
  • Total Stream Length (miles): 42,733.60
  • Average Annual Flow at Station (NHD) (cfs): 36,002.00
  • Population (2010): 2,440,974
Stream Classifications (Pennsylvania)
Designation Miles
Exceptional Value 1977.92
High-Quality Cold Water Fisheries 9023.25
High-Quality Trout Stocked Fisheries 79.30
Trout Stocked Fisheries 2426.92
Warm Water Fisheries 5661.09
Total 19168.48
Stream Classifications (New York)
Classification Use Miles
Class A Drinking Water Source 154.69
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) 7630.29
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 11191.01
  • Land Use
  • Description Percentage
    Water 0.32
    Developed Open Space 4.82
    Low Urban 1.40
    Medium Urban 0.56
    High Urban 0.20
    Barren 0.43
    Deciduous Forest 47.48
    Coniferous Forest 3.05
    Mixed Forest 16.40
    Shrub Scrub 1.04
    Grassland Herbaceous 0.63
    Pasture/Hay 14.85
    Cropland 6.34
    Wetlands 1.83
Underlying Geology
Rock Type Percentage
Dolomite 1.40
Limestone 3.58
Quartzite 1.73
Sandstone 40.33
Shale 52.96
Recent Results
Sample Time 12/2/2022 1:00:00 PM
Temperature  (C) 10.27
Specific Conductivity  (mS/cm)
PH 7.76
Turbidity  (NTU+) 14.94
Dissolved Oxygen  (mg/L) -5
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)
Natural Gas
  • Natural Gas Pads 1927
  • Natural Gas Water Withdrawals 103
Public Water Supply Withdrawals
  • Groundwater 7163
  • Surface Water 377
NPDES Discharges
Description Count
Concentrated Animal Feeding Operation 191
Mining/Quarry 576
Stormwater 621
Wastewater Treatment Plant/Sewage Treatment Plant 874
Other 1673
Stream Impairments
Source Category Miles
Acid Mine Drainage Aquatic Life 3003.86
Agriculture Aquatic Life 2006.20
Animal Feeding Operations Aquatic Life 7.25
Atmospheric Deposition Aquatic Life 444.75
Channelization Aquatic Life 53.42
Coal Mining Aquatic Life 1.79
Combined Sewer Overflows Aquatic Life 15.24
Construction Aquatic Life 9.70
Crop Production Aquatic Life 209.97
Dam or Impoundment Aquatic Life 52.57
Erosion from Derelict Land Aquatic Life 17.44
Highway/Road/Bridge Runoff Aquatic Life 1.90
Golf Courses Aquatic Life 11.30
Grazing in Riparian Zones Aquatic Life 261.85
Habitat Modification Aquatic Life 98.00
Highway/Road/Bridge Runoff Aquatic Life 311.55
Highways, Roads, Bridges Construction Aquatic Life 3.88
Dam or Impoundment Aquatic Life 20.60
Industrial Point Source Aquatic Life 44.64
Landfills Aquatic Life 1.81
Municipal Point Source Aquatic Life 35.64
Natural Sources Aquatic Life 18.99
On-Site Treatment Systems Aquatic Life 25.69
Removal of Vegetation Aquatic Life 95.37
Rural (Residential) Aquatic Life 155.73
Silvaculture Aquatic Life 11.50
Site Clearance Aquatic Life 5.73
Source Unknown Aquatic Life 147.80
Streambank Modifications Aquatic Life 7.08
Surface Mining Aquatic Life 4.16
Urban Runoff/Storm Sewers Aquatic Life 208.48
Source Unknown Fish Consumption 519.50
Agriculture Fish Consumption 21.40
Combined Sewer Overflows Fish Consumption 21.40
Habitat Modification Fish Consumption 21.40
Urban Runoff/Storm Sewers Fish Consumption 21.40
Atmospheric Deposition Fish Consumption 606.40
Municipal Point Source Fish Consumption 28.10
On-Site Treatment Systems Fish Consumption 41.80
Acid Mine Drainage Potable Water Supply 8.70
Source Unknown Potable Water Supply 1.80
Agriculture Recreational 230.00
Source Unknown Recreational 2938.60
On-Site Treatment Systems Recreational 54.30
Urban Runoff/Storm Sewers Recreational 25.10
Combined Sewer Overflows Recreational 11.70