This paper documents the methodology and results of a comprehensive evaluation of
regional conservation potential conducted under the direction of the San Francisco Public
Utilities Commission (SFPUC) for its wholesale customer service area. The study was
conducted with participation, feedback, and concurrence from the 28 SFPUC wholesale
customers and coordination assistance from the Bay Area Water Supply and Conservation
Agency (BAWSCA).
The SFPUC is currently implementing a capital improvement program (CIP) to improve the
reliability of the SFPUC regional water system and reduce its risk of failure. Understanding
the future regional water demand, including demand management potential through water
conservation programs, is an important aspect in planning for system reliability
improvements. This study, undertaken for SFPUC long-term regional planning purposes,
evaluated water demand management for the wholesale customer service area by working
with the 28 wholesale customers and BAWSCA to define a reasonable range of conservation
potential for each individual wholesale customer service area.
The SFPUC planning study involved two phases of work: water demand forecasting and
evaluation of future water conservation potential. The evaluations were conducted in series
using an end-use water demand model, the Demand Side Management Least-Cost Planning
Decision Support System (DSS) model developed by Maddaus Water Management. The DSS
model was applied to each wholesale customer service area individually, and calibrated to the
service area conditions to first project total water demand by end use through the year 2030,
and then evaluate conservation potential for those same service areas. The relative cost-effectiveness of investing more money in conservation as opposed to purchasing additional
water from the SFPUC was reviewed with each customer, along with the results of a benefit-cost
analysis of the individual measures and programs.
Based on compiling the results from the individual customer DSS models, it was found that
the current plumbing and appliance codes would reduce SFPUC wholesale customer service
area 2030 total water demand (estimated at 324 mgd) by about 7.8 percent. Further, the DSS
modeling showed that additional water conservation measures could reduce total water
demands an additional 2-6 percent, depending upon the level of conservation implemented by
the wholesale customers within the concurrence range. Includes 4 references, tables, figures.