The Water Management Act gives the Massachusetts Department of Environmental Protection the authority to regulate ground water and surface water withdrawals in excess of 0.100 million gallons per day (MGD). The Water Management Act was enacted during the 1980's and there were quite a few water suppliers that fell under the new regulations.

The regulations created what is refered to as a "registration" volume which is the amount of water historically withdrawn by the supplier at the time DEP's regulation took affect. Some suppliers have filed for water management permits to allow withdrawals in excess of the registration volume.

The Town of Topsfield has a registration volume of 0.430 MGD and a permitted volume of 0.170 MGD.