Sea-Level Rise Impact on Salinity in the York and Chickahominy Rivers

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Sea-Level Rise Impact on Salinity in the York and
Chickahominy Rivers

• Mark Bennett, USGS
• Study funded Cooperatively with Newport News
  Waterworks

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Acknowledgements

• 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

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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

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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 1940s

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Climate Adaptation Planning

• 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

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Drought Planning
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Sea Level Trends
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Scenarios to Consider
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Scenarios Modeled

• Normal and drought flow conditions in York and
  Chickahominy River
• Low, Median, and High Sea-level Rise Scenarios
• 1. 20th Century rate 3-4 mm/year 30-40 cm by
  2100
• 2. 2oth Century rate 2 mm/year acceleration
  up to 50 cm by 2100
• 3. 20th Century rate 7 mm/year acceleration
  up to 100 cm by 2100

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Large Domain Model of the Chesapeake Bay
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Chickahominy Model Results

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

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Salinity ExcursionsChickahominy River (_at_ Walkers
Dam)
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Chickahominy Model Results
Calibration Results
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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

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Chickahominy Model Results
Higher sea-level conditions increase number of
excursions during lower flow periods ( 7-8 events
!)
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Chickahominy Model Results
October 2005 flow conditions (normal dry
season/year)
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Chickahominy Model Results
October 2002 flow conditions (Severe Drought)
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Nested Grid Model of York River Estuary
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York River Surface Salinity
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York River Surface Salinity
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York River Model Results
October 2005 flow conditions (normal dry
season/year)
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York River Model Results
October 2002 flow conditions (severe drought)
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Summary
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?
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Questions ?

• http//pubs.usgs.gov/of/2011/1191/

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