Minimum Water Supply (AF)

Source Yr. 1 Yr. 2 Yr. 3

Imported 12,628 12,442 12,255

Ground 800 800 800

Total 13,428 13,242 13,055

Based on the above analysis, the City should expect 100% supply reliability during a three year drought period over the next three years.

7.4 CATASTROPHIC INTERRUPTIONS

A water shortage emergency could be a catastrophic event such as result of drought, failures of transmission facilities, a regional power outage, earthquake, flooding, supply contamination from chemical spills, or other adverse conditions. During a disaster, the City will work cooperatively with MWD through their Member Agency Response System (MARS) to facilitate the flow of information and requests for mutual-aid within MWD’s 5,100-square mile service area. In the event of groundwater supply loss, all supply could be imported from MWD, once confirmed that the necessary capacity is available to do so.

Additional emergency services in the State of California include the Master Mutual Aid Agreement, California Water Agencies Response Network (WARN) and Plan Bulldozer. The Master Mutual Aid Agreement includes all public agencies that have signed the agreement and is planned

out of the California Office of Emergency Services. WARN includes all public agencies that have signed the agreement to WARN and provides mutual aid assistance. It is managed by a State Steering Committee. Plan Bulldozer provides mutual aid for construction equipment to any public agency for the initial time of disaster when danger to life and property exists

Emergency Storage Requirements

MWD’s criteria for determining emergency storage requirements were established in the October 1991 Final Environmental Impact Report for the Eastside Reservoir, which is now named Diamond Valley Lake. They were again discussed in Southern California’s 1996 Integrated Resources Plan. MWD’s Board has approved both of these documents. These emergency storage requirements are based on the potential of a major earthquake damaging the aqueducts that transport Southern California’s imported water supplies (SWP, CR

Los Angeles Aqueduct). The adopted criteria assume that damage from such an event could render the aqueducts out of service for six months. MWD’s planning, therefore, is based on 100 percent reduction in its supplies for a period of six

MWD’s emergency planning is based on a greater shortage than required To safeguard the region from catastrophic loss of water supply, MWD has made substantial investments in emergency storage. The emergency plan outlines that under such a catastrophe, interruptible service deliveries would be suspended and firm supplies to member agencies would be restricted by a mandatory cutback of 25 percent from normal-year demand levels. At the same time, water stored in surface reservoirs and groundwater basins under

interruptible program would be made available, and MWD would draw on its out of the California Office of Emergency Services. WARN includes all public agencies that have signed the agreement to ual aid assistance. It is managed by a State Steering Committee. Plan Bulldozer provides mutual aid for construction equipment to any public agency for the initial time of disaster when danger to life and property exists.

Emergency Storage Requirements

’s criteria for determining emergency storage requirements were established in the October 1991 Final Environmental Impact Report for the Eastside Reservoir, which is Diamond Valley Lake. They were again discussed in Southern Integrated Resources Plan. ’s Board has approved both of these documents. These emergency storage requirements are based on the potential of a major earthquake damaging the aqueducts that transport Southern California’s imported water supplies (SWP, CRA, and Los Angeles Aqueduct). The adopted criteria assume that damage from such an event could render the aqueducts out of ’s planning, therefore, is based on 100 percent reduction its supplies for a period of six months. s emergency planning is based on a greater shortage than required To safeguard the region from catastrophic loss of water has made substantial investments in emergency storage. The emergency plan outlines that under such a tible service deliveries would be suspended and firm supplies to member agencies would be restricted by a mandatory cutback of 25 percent from year demand levels. At the same time, water stored in surface reservoirs and groundwater basins under MWD’s interruptible program would be made would draw on its

emergency storage, as well as other available storage. MWD

approximately half of Diamond Valley Lake storage to meet such an emergency, while the remainder is available

seasonal supplies. In addition,

access to emergency storage at its other reservoirs, at the SWP terminal reservoirs, and in its groundwater conjunctive use storage accounts.

Figure 7.3: Lake Hemet Storage Reservoir

With few exceptions, MWD

emergency supply throughout its service area via gravity, thereby eliminating dependence on power sources that could also be disrupted by a major earthquake. The WSDM Plan shortage stages will guide MWD’s management of avai

and resources during the emergency to minimize the impacts of the catastrophe. In addition to the criteria used to develop the emergency storage requirements, in 2005, MWD cooperated with DWR and others on a preliminary study of the potential effects of extensive levee failures in the Delta. This study was limited in scope, and investigated only two of a potential range of scenarios. MWD's analysis showed that its investment in local storage and water banking programs south of the Delta would provide it with the resources necessary to continue to operate under the scenarios investigated. In emergency storage, as well as other MWD has reserved approximately half of Diamond Valley Lake storage to meet such an emergency, while for dry-year and In addition, MWD has access to emergency storage at its other reservoirs, at the SWP terminal reservoirs, and in its groundwater conjunctive use

Lake Hemet Storage Reservoir

MWD can deliver this emergency supply throughout its service area via gravity, thereby eliminating dependence on power sources that could also be disrupted by a major earthquake. The WSDM Plan shortage stages will guide ’s management of available supplies and resources during the emergency to minimize the impacts of the catastrophe. In addition to the criteria used to develop the emergency storage requirements, in 2005, cooperated with DWR and others on a preliminary study of the potential effects of extensive levee failures in the Delta. This study was limited in scope, and investigated only two of a potential range of scenarios. 's analysis showed that its investment in local storage and water banking programs south of the Delta would provide it with the resources necessary to continue to operate under the scenarios investigated. In

2010

URBAN WATER MANAGEMENT PLAN

7 - 6 2010 URBAN WATER MANAGMENT PLAN

SECTION 7: WATER SHORTAGE CONTINGENCY PLAN