SNAP
  • About (current)
  • Methods
  • Map
  • Summary Statistics
  • Sites
    • Bald Eagle Creek near Castanea, Pa.
    • Chemung River at Chemung, N.Y.
    • Cohocton River near Campbell, N.Y.
    • Conestoga River at Conestoga, Pa.
    • Conodoguinet Creek near Hogestown, Pa.
    • East Mahantango Creek near Dalmatia, Pa.
    • Juniata River at Newport, Pa.
    • Kishacoquillas Creek near Reedsville, Pa.
    • Octoraro Creek at Richardsmere, Md.
    • Paxton Creek near Penbrook, Pa.
    • Penns Creek at Penns Creek, Pa.
    • Pequea Creek near Martic Forge, Pa.
    • Raystown Branch Juniata River at Saxton, Pa.
    • Sherman Creek at Shermans Dale, Pa.
    • Susquehanna River at Conklin, N.Y.
    • Susquehanna River at Danville, Pa.
    • Susquehanna River at Marietta, Pa.
    • Susquehanna River at Smithboro, N.Y.
    • Susquehanna River at Towanda, Pa.
    • Susquehanna near Wilkes-Barre, Pa.
    • Swatara Creek near Hershey, Pa.
    • Unadilla River at Rockdale, N.Y.
    • West Branch Susquehanna River near Jersey Shore, Pa.
    • West Branch Susquehanna River near Karthaus, Pa.
    • West Branch Susquehanna River at Lewisburg, Pa.
  • SRBC

Sediment & Nutrient Assessment Program
Station Locations

Map displays Annual Loads, Concentrations, and Yields for the 2021 Water year (October 1, 2020 to September 30, 2021) and Flow Normalized Trends for the period 2005 – 2021*.

  • *Paxton, Kishacoquillas, and East Mahantango (2013 – 2021); Richardsmere (2007 – 2021)

Concentrations in mg/L, load in tons, and yields in lbs/acre

All analyses completed using the USGS statistical model Weighted Regressions on Time, Discharge, and Season (WRTDS) (Hirsch et al. 2010). WRTDSKalman estimates were used for annual concentrations, loads, and yields (Zhang and Hirsch 2019).

Citations

Hirsch, R.M., D.L. Moyer, and S.A. Archfield. 2010. Weighted Regressions on Time, Discharge, and Season (WRTDS), with an Application to Chesapeake Bay River Inputs. Journal of the American Water Resources Association 46(5):857-880.

Zhang, Q. and R.M. Hirsch. 2019. River water-quality concentration and flux estimation can be improved by accounting for serial correlation through an autoregressive model. Water Resources Research 55:9705-9723.