Leaders in the Massachusetts Senate are proposing a bill designed to help improve the state's water and sewer infrastructure.

A 2012 report found Massachusetts is facing a shortfall of approximately $21 billion over the next two decades to keep drinking and wastewater systems in a state of adequate repair.

The Senate initiative would significantly increase the amount local communities can borrow at low interest rates from the state's Water Pollution Abatement Trust to help improve and protect water supplies.

The bill's sponsors say the measure would also create a ``leak classification system'' to make sure high-hazard leaks are fixed quickly while also encouraging renewable or ``green infrastructure'' water projects.