Amy L. Shallcross, PE Operations Supervisor, Water Resources Management Branch

1. Water Balance, Freshwater Flows, and Precipitation Associated with Climate Change in the Delaware Estuary Watershed Amy L. Shallcross, PE Operations Supervisor, Water Resources Management Branch Delaware River Basin Commission

2. Delaware River Basin Commission

3. WHAT DOES DRBC DO? • Manages Resources on a Watershed Basis • Regulates Water Quality and Quantity • Plans for Use of Water Resources • Coordinates / Facilitates • Educates about Water Resources

4. Delaware River Watershed Facts • Nearly 15 million people (about 5% of the U.S. population) rely on the waters of the basin • Drains 13,539 mi² , or 0.4 of 1% of the continental U.S. land area • 216 tributary streams • 4 states, 42 counties, 838 municipalities • 25 Congressional Districts

5. The Delaware River Port Complex (including docking facilities in Pa., N.J., and Del.) is the largest freshwater port in the world.

6. Delaware Water Gap Region Longest River without a main stem dam East of the Mississippi

8. Basin Reservoirs • Water Supply (only) • Penn Forest, Wild Creek, Still Creek, Ontelaunee, Green Lane, Geist, Edgar Hoopes, Union Lake, Lake Hopatcong, and Nockamixon • 48.1 BG • NYC Water Supply and Flow Augmentation • Neversink, Cannonsville, Pepacton • 281.9 BG

9. Photos Courtesy NYC DEP

10. Basin Reservoirs (continued) • Hydropower • Lake Wallenpaupack and Mongaup System (multiple reservoirs) • 45.1 BG • Multi-purpose and Flood Loss Reduction • Prompton, Beltzville, Marsh Creek, Chambers Lake (Hibernia Dam), Blue Marsh, Lake Galena, Francis E. Walter, Jadwin, Merrill Creek • 39.4 BG (WS, WSA) and 71.4 BG Flood Loss Reduction • 414. BG WS/WSA/Power and 71.4 Flood Storage

11. What do we know? • General agreement in model studies: • Temperature (C) +3 to +5 C • Precipitation (%) 0 to +20% • Runoff (%) -25% to +20% • Less confidence in regional precipitation/runoff predictions than temperature • Regardless of sign of precipitation change, significant changes expected in: temperature, annual streamflow cycle, soil moisture, and snowpack. Anticipate more hot days; more variability

12. What do we expect? • Equal or Increased Precipitation • Greater Intensity of Storms • Increased Temperatures • Potential for Extended Droughts • Some Increase in Sea Level Rise • (0.5 m – 5 m by 2100)

13. Uncertainties • Will increased precipitation offset increased water loss due to evapotranspiration? • Will more days for groundwater recharge (unfrozen ground) balance soil moisture deficits predicted with higher temperatures? • How will vegetative cover change?

14. Eastern Plateau, NY > 71 inches Pocono Mountains, PA > 65 inches Northern, NJ > 59 inches Southern, NJ > 27 inches Southern Eastern Piedmont, PA > 55 inches Northern, DE > 44 inches Southern, DE > 17 inches

15. 1955 - 1996 22’ 18’

16. Rutgers – Office of State Climatologist

17. Rutgers – Office of State Climatologist

18. Is it wet? Is it dry?

19. Is it wet? Is it dry?

20. Source: http://www.crh.noaa.gov/Image/eax/climate/prcp_MAM08.gif

22. Drought of the 1960’s

23. Potential Impacts – Water Supply • Water Supply • Prolonged Droughts • Evapotransporation • Loss of Snow Pack • Salinity – Sea Level Rise • Infrastructure • All Coupled with Increasing Demand

24. Changes in Snowpack and Timing of Snowmelt • There will be less snow in the winter; this affects water supply for many who depend on the melting of snowpack as a water source. The timing of snowmelt may also change, prompting water resource managers to change how water supply reservoirs are managed.

26. Jeopardize water supply due to increased salinity levels. Both surface water and groundwater withdrawals in the estuary will be affected. • Increase river flows to push back salt line • Increase costs for water purveyors – moving intake pipes upstream or building desalination plants.

27. NYC RESERVOIR STORAGE DECLINES TO RECORD LOWS November 26, 2001 record low storage for Cannonsville, 3.245 bg or 3.39% of capacity. Cannonsville Reservoir under normal conditions. Cannonsville Reservoir is located on the West Branch of the Delaware River Cannonsville Reservoir (6.5% of capacity).

28. Need and Potential Solutions • Need – More Upstream Storage and Reduced Demand • Potential Solutions • Better reservoir management • New Reservoirs? • New Main Stem Reservoirs? • Use old quarries for storage, Aquifer Storage and Recovery, etc. • More System Interconnections • Sea Barriers?

29. Potential Impacts • Water Supply • Flooding • Increased Precipitation • More Intense Storms • More erosion and debris • Non-Tidal River – Old Towns • Coastal Surge

30. September 2004 April 2005 June 2006 Three Major Floods along the Main Stem Delaware River in less than Two Years

33. Need and Potential Solutions • Need – Minimizing Flood Damage • Potential Solutions • Better Stormwater management - Infiltration, • Protection of Headwaters, Riverine Buffers • Better Land use decisions, LID • Different Management of Existing Reservoirs • Raised or New Reservoirs? • New Mainstem Reservoir? • Moving People from Harm’s Way • Flood Warning/ Flood Mapping

34. Potential Impacts - WQ • Water Supply • Flood Inundation • Water Quality Impacts • Temperature • Dissolved Oxygen • Suspended Sediment • Lower 7Q10 for Wastewater Assimilation/TMDLs • Potential Increase in Waterborne Pathogens

35. FECALCOLIFORM IS WAY D O W N and DISSOLVED OXYGEN IS ↑ FROM 2 PPM TO 7!

36. Needs and Potential Solutions • First –Modeling of Scenarios / Impacts • Issues – • Existing Water Quality Standards • Anti-Backsliding Rules • How to Handle Natural Changes –Tougher Regulation? • Should We adapt to CC-caused WQ Changes?

37. Potential Impacts - Biological • Water Supply • Flood Inundation • Water Quality Impacts • Biological Impacts • Wetlands Inundation/Loss • Change in Spring Thaw Flows • Migratory Patterns • Vegetation Changes • Invasive Species

38. Sea Level Rise - Impacts on the Delaware Estuary • Reduce the amount of natural wetlands and marshes, which act as a buffer, helping reduce non-point source pollution and flooding severity. Wetlands are also an important habitat for wildlife, especially migrating birds and fish.

39. The animals, plants, and forests of the region may shift their habitat and ranges northward due to increased temperatures and potential decrease in water. • Biodiversity among species may also decrease, which can also lead to an increase in invasive species.

40. Already seen: • earlier bird migration and egg laying, • earlier peak discharges in snow-fed rivers, • earlier timing of spring blooms, and • changes in the range and timing of fish migrations in rivers (IPCC 2007) American shad

41. Photo courtesy of USFWS

42. Next Steps • Prepare for Potential Effects • Assess Future Demand and Develop Conservation Strategy • Modify/Create Models with Uncertainty Factors • (e.g. drought of record) • Develop Strategic Plans for Droughts, Floods, Sea Level Rise • Adaptation (vs Fighting Change) • e.g. –Impact of change in forest species, coldwater to warmwater fishery

43. Will New Reservoirs be Needed or Will Many Small Changes Be Enough? • Need for New Reservoirs and Flood Mitigation Dams? or • Combination of • Stormwater Infiltration • Protection of Headwaters • Stream Corridor Protection • Low Impact Development • Use of Old Quarries • Regional Planning • Floodplain Regulation

44. Management Conflicts • Need To Manage For Even Greater Extremes • “Stationarity is Dead” – Need for Uncertainty Factor • Water Managers like to be Conservative – • Do not gamble with water • Need More Water Storage for Supply, Instream Flows, Salinity Repulsion and Voids for Flood Mitigation

45. NEEDS • Localized, Downscaled Climate Change Models • Uncertainty Factors for Droughts and Floods • Linking Models – CC/Hydrologic/Hydrodynamic/Water Quality • Evaluation of Alternatives Effectiveness • Demand Reduction • Small, Local Solutions to Water Management • Evaluation of Water Quality Implications

46. Daily Flow Modeling

47. Time for ACTION !! Integrated Water Management in the Delaware River Basin www.DRBC.net