News & Press

Extreme Drought Declared in Southeast NH

With over 1 million New Hampshire Residents in the midst of a very significant drought (U.S Drought Monitor data for August 2016), EGGI geologist Jeff Marts’ presentation at the 2016 NH Water and Watershed Conference at Plymouth State University on March 18th was particularly timely.  Jeff explained during his talk how historic groundwater level data can be used to develop a monitoring plan to identify incipient droughts while there is still enough time for water utilities to mitigate potential water shortages. 

Droughts can be defined in many different ways and have a particular meaning to different constituencies.  For example, meteorological droughts are defined as a period of time having a precipitation deficiency, which can lead to an agricultural drought (when a soil moisture deficiency occurs) that affects farmers.  Jeff developed an operational definition of a drought that impacts Water Utilities that rely on groundwater.  This definition stated drought is  “A Period of time when groundwater withdrawals from an aquifer exceed groundwater recharge rates, resulting in abnormally low water levels that are trending downward, potentially threatening the ability of the utility to meet future water demands.”

Fortunately, groundwater in New Hampshire (and much of the Eastern Seaboard) is a renewable resource that provides a very resilient water supply in the event of short term droughts, and is used in many localities as a main water source, and/or backup/supplemental supply to vulnerable surface water sources.  However, even groundwater resources can be susceptible to the impacts of persistent, long-term drought conditions. 

Water utilities have several tools at their disposal to manage their water supplies and limit water use, if necessary.  Often, water utilities don’t recognize impending water shortages until it is too late to take corrective action.  Jeff discussed in his presentation how utilities can collect water level data throughout the year and continuously evaluate the data to see if particular trigger levels are reached.  Trigger levels are pre-defined water levels that are identified based on the hydrogeology of an aquifer and a particular well field that are designed to alert a utility to take progressive steps to minimize lowering groundwater levels in time to mitigate potential adverse impacts. 

An aquifer-specific drought monitoring system not only provides early warning and management tools to a utility, but it also provides a scientific basis for effectively communicating to the public (as well as government officials) why water restrictions are necessary to ensure ongoing availability of water resources.  Jeff also spoke about additional steps water utilities can take to ensure long-term drought resiliency, such as developing backup water sources and using artificial recharge to augment natural recharge.

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