June 12, 2007 > Delta pumping interruption impacts local water districts
Delta pumping interruption impacts local water districts
Intermittent use of the Banks Pumping Station in the Delta and low reserves of a small reservoir has compromised our local water supply. The following statement was released by the Alameda County Water District (ACWD) to the public regarding the effect of these problems. TCV asked ACWD Water Resources Planning Manager Eric Cartwright, P.E. and Operations Manager Karl Stinson for additional information. Their comments follow the public statement.
Informational Release from Alameda County Water District
Available at www.acwd.org
The Alameda County Water District (ACWD) Board of Director's held a special Board meeting on Friday, June 1st to review the status of ACWD water supplies in light of the recent announcement that the State Water Project's pumping facilities in the Delta have been shut down.
ACWD relies on State Water Project (SWP) supplies, pumped from the Delta, to meet approximately 40% of the water supply needs for the cities of Fremont, Newark and Union City. These Delta water supplies are conveyed to the ACWD service area via the South Bay Aqueduct (SBA). The SBA provides the sole source of supply for the District's two surface water treatment plants, as well as providing a source of replenishment for the District's groundwater supplies.
Despite the Delta pumping outage, ACWD continues to receive a limited quantity of water via the South Bay Aqueduct from SWP water stored in Del Valle and Bethany Reservoirs. However, the total amount of water delivered through the SBA to ACWD has been reduced by over 50%. As a result, production capacity at the District's two surface water treatment plants has been limited, and groundwater replenishment activities have been temporarily suspended.
As reported at the Board meeting, ACWD does not expect that this seven to 10-day shutdown will have any immediate impacts on water deliveries to its customers. ACWD has sufficient local reserves and a diverse portfolio of production facilities to meet all of its customers' water demands during the projected time frame of the outage. ACWD's other sources of supplies include local groundwater, desalination, and water purchased from San Francisco Regional Water System.
Therefore, there is no immediate need for voluntary or mandatory cutbacks in water use by ACWD customers. However, given the ongoing dry-year conditions, coupled with the uncertainty of an extended Delta pumping outage, ACWD is asking customers to continue to use water wisely and efficiently. Reducing water use this year will help ensure that there are adequate supplies for next year if the dry conditions persist.
Recommended indoor and outdoor water conservation measures for ACWD customers include:
Indoor Water Conservation Tips:
* Repair running toilets and leaky faucets
* Turn off the tap when brushing your teeth, washing your hands and shaving
* Run your washing machine and dish washers only when you have full loads
* Replacing old toilets with newer, water efficient models
* Install water saving devices such as low flow shower heads and faucet aerators
* Upgrade to a new, water efficient washer
Outdoor Water Conservation Tips:
* Water your lawn every three days, and only in the morning
* Adjust sprinklers to avoid watering the sidewalk or driveway
* Prevent irrigation runoff by watering for shorter periods
* Choose native and drought tolerant plants for your landscape
In the event that the Delta pumping outage is extended and ACWD's SWP supplies are further reduced, ACWD's production at its surface water treatment plants may need to be further reduced. Under this scenario, ACWD may not have sufficient water production capacity to meet all peak-day demands if a hot spell occurs. Accordingly, the Board of Directors authorized a contingency plan that calls for a voluntary 10% cutback in water use by ACWD's customers, should this occur.
Under this contingency plan, ACWD's customers would be asked to reduce landscape irrigation amounts by 20%, and to limit landscape irrigation to even/odd days, depending on their street address. However, these requested water reductions would only be implemented in the event of an extended outage in which our Delta water imports are further cutback. If this additional level of conservation is needed, ACWD will notify customers through a focused mailer, media outreach, newspaper ads, updates to the web-site and other venues.
Please note that the contingency plan (calling for a voluntary 10% reduction in water use) would only be implemented if both of the following conditions occur:
1. The Delta pumping outage extends significantly beyond 10 days; and
2. The supply available to ACWD from Bethany Reservoir (and delivered via the South Bay Aqueduct) is reduced below current levels.
Additional comments by ACWD Water Resources Planning Manager Eric Cartwright, P.E. and Operations Manager Karl Stinson:
TCV: What is the cause of the delta pumping problem?
ACWD: The smelt population is at dangerously low levels in their habitat, the Delta. These fish are found in different areas depending on the season. Right now, they are in an area that will cause them to be drawn into the pumps for Bethany Reservoir.
TCV: Is this unusual?
ACWD: They tend to move into an area of the Delta where they can be pulled into the pumps during this time of year, but usually the water temperature warms up and the smelt migrate further west in Suisun Bay where temperatures are cooler. This takes them away from the pumps. Once the temperature reaches 77 degrees Fahrenheit, Smelt will no longer stay in the area.
TCV: Do the affected pumps stop at this time of year anyhow due to the smelt migration?
ACWD: In past years, the smelt population has been high enough that any "take" by the pumps has not been a danger to their existence. Now, there is concern about a precipitous drop in their numbers and the effect of any further reduction.
TCV: What is the practical effect on us?
ACWD: We have had to cut back on deliveries from the South Bay Aqueduct and, in the short term, peak day demands could be affected. If the pump problem continues and if we experience problems with our system, fires or power outages, we would have to use emergency reserves. That is what we have them for, but a combination of problems could lead to more drastic measures.
TCV: Does this affect the Santa Clara Valley Water District (SCVWD)?
ACWD: Yes it does. Alameda County Flood Control District, Zone 7, also known as Zone 7 Water Agency, located in the Livermore/Pleasanton area supplies water from the South Bay Aqueduct (California Water Project) to three south bay water contractors including Santa Clara Valley Water District. Currently, SCVWD is able to supplement through the San Luis Reservoir, but that supply is being rapidly drawn down and will present a serious problem if the South Bay Aqueduct is compromised for a lengthy period.
TCV: What is the timeframe before there are more serious repercussions from the smelt problem?
ACWD: The problem is that the water held in Bethany Reservoir, will only last seven to ten days. After that period, the South Bay pumping plant will have to shut down further decreasing our deliveries.
TCV: Can we use the reserve water in Kern County?
ACWD: The only way we can use that is through exchanges. If farmers use the water we have stored, we would take water they usually get from the State Water Project. It only works if the Banks pumping plant is operating bringing water to Bethany Reservoir and the South Bay Aqueduct.
TCV: If the smelt do not move, what happens?
ACWD: The Department of Water Resources has just announced that they will begin pumping on a very limited basis. This will be enough to refill Bethany Reservoir and allow us to continue receiving water. Federal pumps that are close by have continued to operate at a reduced level with no effect on the smelt. The hope is that even if the problem persists, we will continue to receive water through the aqueduct and ask for voluntary reductions in water usage from ACWD customers as outlined in our statement.
The news, so far, is not promising since Delta water temperature has not increased enough to cause the smelt to move and predictions are for this to happen no earlier than next month.