Groundwater Overlay Zoning

Water Overlay Zones

North Kingstown’s Groundwater Overlay Zoning establishes two overlay zones. GW1 includes the Wellhead Protection Areas, which are the land areas that are within the zones of contribution or the areas where the groundwater is being pulled toward the pumping wells. In essence, this is the water that we may drink at some point in time in the future. These are the most critical areas for protecting our drinking water and communities and water suppliers are required to develop programs for source water and wellhead protection.

Groundwater Reservoirs

In the North Kingstown Groundwater Overlay Ordinance GW1 also includes the Groundwater Reservoirs, which are the areas where the water below the ground is abundant (40 feet of saturated thickness) and the subsurface sand and gravel allows water to move more readily (known as transmissivity).  


At the time, these reservoir areas were added to GW1 because the Town desired to protect any areas where new wells might possibly be located, within the last five years. However, State regulators have indicated to the Town that the installation of new wells will not be permitted, as they have determined that public water supply wells are causing unacceptable impacts on certain river systems.   

Impact on Aquatic Wildlife

The wells are intercepting groundwater that would normally have discharged to the rivers, and this reduction in the water level in the river is negatively affecting aquatic habitat. The HAP River system has been identified as a watershed where the amount of water being pumped for water supply exceeds what is needed to protect the fish and other species that rely on the amount of water in the river. 

Changes in Regulatory Designation

The regulatory agencies will no longer allow the construction of new water supply wells in these aquifers. Because of this new reality, we have now made the determination that reservoir areas that are not part of a defined Wellhead Protection area are more appropriately protected by a GW2 designation. 

GW2 Designation

The GW2 designation includes the Groundwater Recharge Areas as mapped by the US Geological Survey (with slight modifications to be as protective as possible). These are the watershed boundaries of the Hunt, Annaquatucket and Pettaquamscutt (HAP) River basins.

What this means is that the elevations of the groundwater table are sloped so that the groundwater moves naturally toward the Wellhead Protection Areas and rivers, and ultimately the Narragansett Bay.

In Summary

The effective protection of our drinking water quality first involves identifying the areas where the subsurface groundwater is being drawn into our wells or the Wellhead Protection Areas. The second level of protection is identifying those areas where the groundwater moves naturally toward the wells and rivers. This includes the Groundwater Recharge Areas and the portion of the Groundwater Reservoirs that are beyond or outside of the Wellhead Protection Areas. 

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