Why Is This Important?
Communities need safe, clean drinking water and adequate supplies to accommodate their residential and nonresidential needs.  Currently, San Mateo County has both.  The county has limited local sources of water, however, and relies heavily on the San Francisco Public Utilities Commission’s (SFPUC) regional water system.  The SFPUC system gets 85 percent of its water from Sierra Nevada snowmelt stored in the Hetchy Hetchy reservoir in Yosemite National Park.  The remaining 15 percent comes from local Bay Area watersheds.

Four main factors could impact or endanger the balance between the county’s future water supply and demand: population growth, drought, an earthquake, and climate change.

  • Population growth: Primarily because of population growth, demand for water in San Mateo County is projected to be nearly 25 percent higher in FY 2030-31 than it was in FY 2005-06. 
  • Drought: San Mateo County has experienced drought in the past, most recently in the early 1990s, and will experience drought conditions in the future.  Currently, the SFPUC has a water shortage plan that could lead to cutbacks of up to 30 percent during an extended drought.
  • Earthquake: The regional water system crosses major fault lines in the Bay Area and a major earthquake could damage the system and lead to supply disruptions.  The SFPUC has adopted a capital improvement plan to repair and seismically upgrade the system’s infrastructure.  The expected completion date for the various projects is 2015.
  • Climate change: Rising temperatures from climate change could reduce annual snowpack in the Sierra Nevada because of a rise in the snowline, a thinner snowpack at low or medium elevations, or an increased amount of precipitation falling as rain rather than snow.  Increased evaporation rates due to climate change could also increase water demand for agriculture and landscaping. 

What Is a Sustainable State?
A sustainable state is one where water supplies and demand for water resources are in balance and there is a diversity of supply to reduce the risk of shortages or disruptions from any single source.

How Are We Doing?
Nearly all San Mateo County residents are serviced by water agencies (individual cities or water districts) that are members of the Bay Area Water Supply and Conservation Agency (BAWSCA).  BAWSCA agencies, both those within San Mateo County and those in Alameda and Santa Clara Counties, have a combined Master Water Sales Agreement with the SFPUC that assures an annual supply of 184 million gallons of water per day (mgd).  The agreement expires in 2009, but the supply assurance survives the contract until a new agreement is reached.

Water agencies within San Mateo County are allocated 90.5 mgd of the total.  Because of population growth, BAWSCA projects that the county will need more than 90.5 mgd annually by FY 2010-11.  Having demand above the supply assurance could lead to an increase in water rates or other measures to reduce demand if water supplies are not available.

 


What does one million gallons of water look like?
If you wanted to build a swimming pool that held one million gallons, it would need to be 267 feet long, 50 feet wide, and 10 feet deep!”



Supply

  • In FY 2005-06, of the 89.1 mgd of water used by BAWSCA agency customers in San Mateo County, 95 percent came from the SFPUC regional water system (84.7 mgd).  The remaining 5 percent was met primarily through local groundwater and surface water sources. 

Data source: Bay Area Water Supply and Conservation Agency

  • Projections to FY 2030-31 show that the BAWSCA agencies in the county will continue to receive at least 90 percent of its water supply from the SFPUC.  Recycled water use is anticipated to grow to 1 percent of water supply because of the Redwood City recycled water project. 
  • Among local water agencies, the City of San Bruno relies least on water supplied by the SFPUC.  In FY 2005-06, 45 percent of San Bruno’s water supply came from local groundwater sources. 
  • Other water agencies with significant local water sources include Coastside County Water District (20 percent of its supply came from local groundwater and surface water), California Water Service – Bear Gulch District (12 percent of its supply came from surface water from the Bear Gulch Reservoir), and Daly City (10 percent of its supply came from local groundwater).
  • In FY 2005-06, 14 of the 19 water agencies in San Mateo County received all of their water from the SFPUC.

Demand

  • In FY 2005-06, annual water use among the 19 BAWSCA agencies in San Mateo County totaled 89.1 mgd, 8 percent less than in FY 2000-01.  Wet spring weather that led to decreased demand for irrigation in FY 2005-06 was the primary reason for the decline in water demand from FY 2000-01.
  • In FY 2005-06, residential water use accounted for 68 percent of total water use, roughly the same percentage as in previous years.  Of the
    residential use, two-thirds is for indoor water use, primarily toilets and washing machines.

Data source: Bay Area Water Supply and Conservation Agency

  • Average residential per capita consumption in the county was 87.1 gallons per capita per day.  Residential water use is correlated with land use, climate, and income.  Affluent communities tend to have higher outdoor water usage than other communities because of larger landscaping needs.
  • Per capita residential water use in the county was highest in the Town of Hillsborough (276.9 gallons per capita per day) and lowest in the Westborough Water District located in South San Francisco (48.8 gallons per capita per day). 

Data source: Bay Area Water Supply and Conservation Agency (see appendix
for service areas of each water district)

  • Total annual demand in the county is projected to increase to 111.7 mgd by FY 2030-31.  More than five mgd of that demand is expected to be mitigated by conservation, primarily from the impact of existing water-saving plumbing codes. 

Data source: Bay Area Water Supply and Conservation Agency

What Can We Do?
With population growth driving an increase in demand and potential threats to future water supplies from drought, earthquakes, and climate change, San Mateo County will need to pursue aggressive conservation or expand its sources of water supply to reach a sustainable state.

The California Urban Water Conservation Council has compiled a list of conservation Best Management Practices (BMPs) for water agencies.   The implementation of these BMPs varies across the county’s water agencies.  In some cases, individual BMPs are considered to be not currently cost effective or not relevant to an agency’s customer classes.

What is a conservation Best Management Practice?
(a) An established and generally accepted practice among water suppliers that results in more efficient use or conservation of water; or (b) A practice for which sufficient data are available from existing water conservation projects to indicate that significant conservation benefits can be achieved, that the practice is technically and economically reasonable and not environmentally or socially unacceptable, and that the practice is not otherwise unreasonable for most water suppliers to carry out.

 

In FY 2005-06, Redwood City had implemented 14 of the 15 BMPs, the highest total in the county.  Four other cities or agencies (Burlingame, Coastside  County Water District, Daly City, and Millbrae) had implemented 13 of the 15 BMPs.

Data source: Bay Area Water Supply and Conservation Agency

The council is also studying other potential programs or practices to add to its list of BMPs, including:

  • Economic incentives and disincentives to encourage water conservation.
  • Efficiency standards for water-using appliances and irrigation devices.
  • Replacement of additional water-using appliances and irrigation devices with ones that use water more efficiently.
  • Retrofit of existing car washes.
  • Reuse of graywater (wastewater from household uses other than toilet water).
  • Conservation in swimming pools and spas including covers to reduce evaporation.
  • Restrictions or prohibitions on devices that use evaporation to cool exterior spaces.
  • Point of use water heaters, recirculating hot water systems, and hot water pipe insulation.
  • Efficiency standards for new industrial and commercial processes.

Lessons from Redwood City
In FY 1998-99, Redwood City began exceeding its allocated portion of the assured supply under the SFPUC Master Water Sales Agreement (11.4 mgd compared to a supply assurance of 10.9 mgd).  Since then, Redwood City has continued to exceed its supply assurance by roughly 0.9 mgd.  Projections showed that the city’s water demand would continue to grow resulting in an inability to meet normal water demands without conservation or water recycling.

In 2001, Redwood City began introducing new water conservation programs aimed at both residential and nonresidential customers.  These included:

  • Distribution of water conservation kits including free showerheads and aerators for households (2,239 distributed to date).
  • Rebates to customers who purchase high-efficiency clothes washers (2,768 rebates to date).
  • Free residential water use surveys, including checking toilets, showers, and faucets for leaks (1,042 to date).
  • A high-efficiency toilet replacement program (8,784 toilets to date).  
  • Customized water use budgets for customers with dedicated landscape irrigation meters.  The budgets are based on weather conditions and site characteristics including type of plants.  Also offered are site surveys by an irrigation expert to improve irrigation efficiency and scheduling.
  • Conversion of natural grass playing fields to synthetic turf to reduce irrigation demands.
  • A large landscape conservation program aimed at reducing water use.  Reductions were achieved at 66 of 75 homeowner association sites and 22 of 28 city parks.
  • Education programs for schools.
  • Distribution of newsletters to customers with tips and advice for conserving water.

In 2003, the Redwood City Council approved a project to deliver recycled water for nonpotable uses in the city.  In 2007, the recycled water project saved the city over 30 million gallons of water.  Projections show that the city’s future annual water supply will include roughly one mgd from recycled water.

Through its water conservation efforts, Redwood City is expected to reduce its annual demand by 0.7 mgd.  With additional water made available as a result of recycling, Redwood City will be below its supply assurance allocation and be able to provide additional water supply for future users.

What can you do?
Indoor
Ø Check for water leaks
Ø Take shorter showers
Ø Install low-flow showerheads
Ø Equip faucets with aerators
Ø Replace your old toilet with a high-efficiency toilet
Ø Upgrade to a water-efficient washing machine
Ø Wash only full laundry loads
Ø Turn off water while brushing teeth and washing dishes

Outdoor
Ø Plant drought tolerant species
Ø Water your lawn only when it needs it
Ø Water during the cool part of the day
Ø Place mulch around trees and plants
Ø Install shut-off nozzles on garden hoses
Ø Sweep sidewalks and driveways
Ø Position sprinkler heads so that the lawn is watered, not the sidewalk
Ø Check for broken sprinkler heads or irrigation leaks

For more water saving tips, go to www.watersavinghero.com.


See appendix page 70, CLICK HERE.  Researchers: Joyce Routson and Joe Rois