Section 61. As used in this section and sections 62 to 69, inclusive, the following words shall have the following meanings unless the context clearly requires otherwise:
''Governmental unit'', a city, town, county, water district, wastewater district, municipal water and sewer commission or regional water and sewer district commission established under chapter 40N or by special act or an independent water and sewer commission; provided, however, that ''governmental unit'' shall not include the Massachusetts Water Resources Authority.
''Local legislative body'', in a city, the city council, in a town, the town meeting or as otherwise more specifically defined by the municipal charter, municipal water and sewer commission or regional water and sewer district commission established under chapter 40N or by special act, in a district, the district meeting, in an independent water and sewer commission, the commissioners.
''Water storage facility'', an above ground or below-ground facility or tank, standpipe, water tower or other building or structure used to store water for, without limitation, public drinking water supply and fire protection.