Ground Water Assessment Drought Management Advisory Council Meeting April 1, 2010 Nat Wilson ( or Ground Water Management Section North Carolina Drought Management Advisory Council Meeting and Drought Tools Workshop, 1-Apr 2010

Drought Indicator Wells  48 wells with a 30 year average record, records range from 4 to 62 years long  20 wells monitored by USGS Automatic recorders, hourly data, real-time access Automatic recorders, hourly data, real-time access  28 wells monitored by DWR Automatic recorders, hourly data, downloaded quarterly Automatic recorders, hourly data, downloaded quarterly  All respond to rainfall within hours of event

Drought Indicator Wells Current conditions tab on

March 2009 March 2010

Surface Water Flows & Ground Water Levels Near Mocksville Davie County (feet 3 /second) (feet elevation – mean seal level)

Surface Water Flows & Ground Water Levels Near Como Hertford County (feet 3 /second) (feet elevation – mean seal level) 1 2 2

First Event: <0.2 inches of rain at Como Well & 0.6 to 1.8 inches in the basin above Potecasi Creek gage Second Event: >6 inches of rain at both the Como Well & in the basin above Potecasi Creek gage

Ground Water  Ground water levels are a measure of the amount of water stored that is available to discharge to surface water features  Discharge from ground water to surface water is called “base flow”  Base flow keeps surface water features flowing when rainfall is lacking  Ground water does not flow in under- ground rivers, but slowly through fractures and pore spaces in the subsurface

More wells reached their minimum of record in 2007 than in any other year – even Eight wells reached their minimum of record in 2008.