Mark Bennett, USGS Study funded Cooperatively with Newport News Waterworks

Presentation derived primarily from study entitled: “ Simulated Changes in Salinity in the York and Chickahominy Rivers as a Result of Projected Sea- Level Rise in the Chesapeake Bay” Karen C. Rice, Mark R. Bennett, and Jian Shen

Peninsula Water Supply  NN Waterworks - Chickahominy River, five reservoirs, & desalted groundwater (62 mgd)  Williamsburg – one reservoir; interconnections  JCC & York County: groundwater; interconnections  Regional sharing Agreements

Chickahominy River  Primary source of fresh water to the region  Limited source during droughts due to low flows and salinity  Tidal barrier dam designed/installed in 1940’s

Warming impacts on surface water quality  Warming impacts on surface water quality  Drought Intensity and frequency changes  Demand Patterns (including population shifts and seasonal peaking changes)  Sea Level Rise, Storm Surge, Salinity Gradients

Sea Level Trends

Scenarios to Consider

Normal and drought flow conditions in York and Chickahominy River Low, Median, and High Sea-level Rise Scenarios th Century rate = 3-4 mm/year; cm by oth Century rate + 2 mm/year acceleration; up to 50 cm by th Century rate + 7 mm/year acceleration; up to 100 cm by 2100

Large Domain Model of the Chesapeake Bay

Chickahominy Model Results Model development, testing and calibration by VIMS and USGS Adapted Chesapeake Bay model and river models (HEM-3D)

Salinity Excursions Chickahominy River Walkers Dam)

Calibration Results Chickahominy Model Results

 Surface salinity at Walkers Dam on the Chickahominy River  3 documented historical events  30 cm rise increases duration slightly, increases concentration significantly Chickahominy Model Results

Higher sea-level conditions increase number of excursions during lower flow periods ( 7-8 events !) Chickahominy Model Results

October 2005 flow conditions (“normal dry season/year”) Chickahominy Model Results

October 2002 flow conditions (Severe Drought) Chickahominy Model Results

Nested Grid Model of York River Estuary

York River – Surface Salinity

York River Model Results York River Model Results October 2005 flow conditions (“normal dry season/year”)

York River Model Results October 2002 flow conditions (severe drought)

Sea-Level rise will impact the freshwater-salt water – brackish water gradients in the York River and Chickahominy River. Changes will be most notable during low flows and in areas with a lower volume of flow What are the potential implications for habitat?

Questions ? Quality. Reliability. Community.