Each well serves as an indicator of regional hydrologic conditions, registering changes in the amount of water stored in known aquifers. This information can be used to compare conditions today with those existing at some time in the past or to predict future conditions. For example, such comparisons enable the severity of droughts to be assessed. The record of water level measurements over time not only reveals general hydrologic trends but also contains detailed information about how aquifers with different characteristics respond to hydrologic events of various magnitudes and durations. Such information provides professional hydrogeologists with a better understanding of the role that groundwater plays in the hydrologic cycle.
As of 2008, the USGS groundwater network consists of 25 monitoring wells in 22 New Hampshire towns (Map). NHGS staff and volunteers monitor 22 of these wells in 20 towns.
In 2005, NHGS refurbished an existing USGS well located in Epping and incorporated the well into the existing network. Increased water demands due to population growth coupled with an increase in impervious surface area in the Seacoast region raises concerns about the sustainability of future water resources. Increasing the density of long-term observation wells will provide greater insight into this potential problem.