The present day Missouri River Treatment Plant was constructed in 1960 and is located North East of Helena at 2560 Canyon Ferry Road.
Raw water is supplied by an underground pipe from the Helena Valley Regulating Reservoir.
The regulating reservoir is part of the Helena Valley Irrigation District and is only a supplier of water. The regulating reservoir and its water are not owned by the city and we must purchase all water that is used. The water is treated with a variety of chemicals to clean the water and purify it. The water is fed into the system and the excess is stored in Malben and Woolston reservoirs. That is why it is called the Malben - Woolston system.