The Water Facilities Authority (WFA) was formed under a Joint Exercise of Powers Agreement (JPA) on February 19, 1980 for the purpose of acquisition and construction of facilities to supply potable water to the inhabitants of lands within the boundaries of its members.

The original member agencies were:

•  City of Chino
•  City of Ontario
•  City of Upland
•  Monte Vista Water District
•  Cucamonga County Water District
•  Chino Basin Municipal Water District

On February 21, 1984, Amendment Number One to the Agreement was executed whereby Chino Basin Municipal Water District ceased to be a member and the County of San Bernardino (Waterworks District Number Eight) and Three Valleys Municipal Water District became members.

On August 25, 2009, the Third Amendment to the Joint Exercise of Powers Agreement was executed to replace Agreement Section 4(f) in its entirety with the following:

“(f) “Original Member” or “Original Party” means the City of Ontario, the City of Chino Hills, the City of Chino, the City of Upland and Monte Vista Water District.”