DISTRIBUTION OF WATER
The Providence Water Supply Board sells water to 73,800 retail customer connections including houses and businesses in Providence, Johnston, North Providence and Cranston and to 9 wholesale communities serving a number of additional municipalities within the State. Providence Water presently supplies approximately 60 percent of the state's drinking water. Of the water produced, 36 percent is supplied to the residents of Providence, 22 percent to the retail districts outside of Providence, and 42 percent goes to the wholesale water districts.
Finished water is transmitted from the clearwell to the distribution system through two major transmission lines. The 90-inch diameter Scituate Tunnel and Aqueduct transports water from the clearwell to the distribution system in an easterly direction, generally along a route that parallels Route 12, ending at the siphon chamber near Interstate 295. From the siphon chamber the transmission line splits into two lines, a 60-inch diameter concrete conduit, and a 66-inch diameter steel pipeline. The 60-inch line continues to feed the Neutaconkanut and Bath Street Pumping Stations and the Neutaconkanut Distribution Storage Reservoir. The 66-inch line continues to the general area of Budlong Road in Cranston from where further distribution begins.
The second major transmission line is the Supplemental Tunnel and Aqueduct which starts at 78 inches in diameter an transports water in a southeasterly direction through the northern section of West Warwick to the existing connection and the former Big River Reservoir development. At this point, the transmission line expands to 102 inches in diameter and turns northerly to terminate in the general area of Budlong Road in Cranston where further distribution begins. The capacity of the 90-inch line is 100 MGD and the capacity of the 78 inch lines is 77 MGD. The 78 inch line flows into the 102 inch line.
The retail distribution system is serviced by three separate pressure zones. The Low Service Area maintains pressures of between 37 and 98 PSI at the consumer tap and serves areas with elevations of between 0-140 ft above sea level. This zone delivers approximately 71.5 % of the total retail water. The High Service Area supplies consumers at elevations of 140-220 ft above sea level with pressures ranging from 36 to 71 PSI. The Extra High Service Area services those customers above 220 ft with pressures between 36 and 77 PSI.