Att13_IG2_Delta_1 of 2South Orange County WMA
ATTACHMENT 13
SOUTH ORANGE COUNTY IRWM IMPLEMENTATION GRANT PROPOSAL
IRWM PLAN – REDUCE DELTA DEPENDENCE
I.Portions of Adopted IRWM Plan that Reduce Dependence
Over 90% of South Orange County Watershed Management Area’s (WMA) water supply is from imported water from the Sacramento-San Joaquin Delta region and the Colorado River. The Municipal Water District of Orange County (MWDOC) contracts with the Metropolitan Water District of Southern California (Metropolitan) a state water project contractor,to provide this imported water to South Orange County. As population continues to increase and water supplies are increasingly limited, the need to reduce dependence on imported water supply becomes even more critical.
The South Orange County IRWM Plan adopted in2005 considers long-term regional planning and projects to enhance local water supplies to offset imported water demands and reduce dependence on the Sacramento-San Joaquin Delta for imported water supply. Many projects are planned over the next 10 to 20 years to help achieve this goal. All projects within the IRWM Plan are essential to maximizing limited water resources, protecting water quality, and enhancing the environment.
The IRWM Plan components that reduce dependence on the Sacramento-San Joaquin Delta for imported water supply include the Water Supply, Groundwater Management, and Water Conservation objectives, shown on pages 2-1 to 2-15 of the IRWM Plan, which are also attached as Att15_IG1_Deltawater 2 of 2. There are many types of projects that help implement theseIRWM Plan Objectives and, in turn, help reduce dependence on the delta for water supply. The following identifies these types of projects and describes how they help meet each objective and reduce dependence on the delta for water supply:
Water Supply Objectives
Water Supply Projects- A primary goal of the IRWM Plan is to present and discuss an integrated planning approach for protecting the state’s water resources, including the Sacramento-San Joaquin Delta. The continued development of projects and plans to pursue such a goal is vital to the economic and environmental health of the region.
To meet the Water Supply Objectives, the IRWM Plan lists a variety of projects, including infrastructure improvements, desalting and recycling projects, and water use efficiency programs that are planned for the WMA. These projects are effective tools to generate not only drought year water supply, but “regular year” water supply as well. By cleansing tainted groundwater supplies or recycling wastewater and urban runoff, previously unusable sources of supply are available to meet water demands. These new local water supplies help reduce reliance on imported water from the Delta by offsetting demand. Using recycled water to meet landscape irrigation, one of the WMA’s largest demands, helps tremendously with reducing imported water supplies, not to mention reducing greenhouse gas emissions from reduced conveyance energy costs.Processing and storage facilities are important to improve both system and supply reliability. Other planned projects, such as stormwater capture and urban runoff treatment facilities, contribute directly to both short-term and long-term storage. Diversion of floodwaters to recharge basins or to storage for reuse will mitigate the dangerous characteristics of flooding as well as augment the available water supply. Watershed planning, including invasive species removal and other habitat restoration projects will enhance water quality and ecosystem vigor.
An extensive infrastructure network makes the delivery of water possible in South Orange County. Figure 3-9 shows the Regional Imported Water Distribution System and Water Agencies. The Metropolitan Water District of Southern California (MWD) is the regional wholesaler of imported water. South Orange County purchases water from MWD through MWDOC. MWD’s imported water system that serves South Orange County comes primarily from the Colorado River and from the East Branch of the California Aqueduct South Orange County’s imported water supply is treated at the Diemer Filtration Plant in Yorba Linda, and transported through two major pipelines to the southern portion of the county; the East Orange County Feeder No. 2 and the Allen McColloch Pipeline. Local delivery is then facilitated primarily through the Aufdenkamp Transmission Main, the Joint Transmission Main, and the South County Pipeline. Water supplies then move into each local water supplier’s infrastructure, which includes distribution mains, pump stations, reservoirs, wells, and other system components. The coastal communities in South Orange County also receive a small supply from the Orange County Feeder, which is fed from the Weymouth Filtration Plant and at times from the Jensen Filtration Plant.
IRWD Interconnection Project - This project became operational in 2009 and involved construction of a permanent interconnection and pumping facilities between the IRWD potable water distribution system and the Joint Regional Transmission Main (JRTM) and the Aufdenkamp Transmission Main (ATM) that conveys water into South Orange County. The project has the ability to transfer up to 30 cfs of supplies during emergency situations only.
SMWD Upper Chiquita Reservoir Project - SMWD constructed the Upper Chiquita Reservoir with a capacity of 244 MG, near Oso Parkway and the 241 Toll Road. The reservoir will act as a large-scale emergency potable water supply during planned or unplanned service disruptions for South Orange County agencies. Construction began in 2009 and was completed in October 2011. The Upper Chiquita Reservoir is located on the western slope of Chiquita Canyon, just north of Oso Parkway in the City of Rancho Santa Margarita. The 244-million gallon Upper Chiquita Reservoir is the largest domestic water reservoir built in south Orange County in nearly 45 years.
San Juan Capistrano Recycled Water – The City of San Juan Capistrano is currently working with its neighboring agencies SMWD and MNWD to make arrangements to use recycled water, when available from these agencies. Plans for a local recycled water treatment plant at SOCWA’s Latham Plant have been indefinitely delayed.
ETWD Recycled Water Distribution Capacity Expansion – ETWD is expanding its recycled water distribution capacity. The project will construct a new recycled water distribution piping supplied by imported tertiary treated recycled water from MNWD and IRWD. The proposed project, expected to be in service by 2015 will increase ETWD’s recycled water supply by as much as 750 AFY.
Imported Water Reliability Projects- Two distinct but related issues must be addressed for South Orange County’s regional water resources: 1) The imported water supply upon which the WMA is dependent; and 2) the local water supply which improves the WMA’s water supply and system reliability. The imported water supply accounts for more than 90 percent of the WMA’s potable water supply, and is obtained through the regional wholesale agencies. The local water supply, though smaller in amount, is in many ways much more critical in that it involves not only developing a usable supply to improve overall water supply reliability but also requires maintaining and protecting the area’s ecological functions dependent on the availability of high quality surface water and groundwater. Since South Orange County imports a predominant amount of its water needs from outside of the area, it is not surprising that the southern part of the county is concerned about either planned or emergency outages of the import system that could be caused by natural or man-made events resulting in a disruption of water supply. Supply concerns could be caused specifically by:
•Emergency shutdowns or outages of facilities such as Metropolitan’s Diemer Water Filtration Plant or major supply pipelines;
•Prolonged droughts on either or both of the State Water Project or Colorado River Aqueduct imported water systems; or
•A lack of implementation of other planned local water projects so that growth needs are not met.
One of the goals of the IRWM Plan is for all of the South Orange County agencies to work together to make the necessary investments to mitigate or minimize impacts from these types of events. Development of local supply sources, regional interconnections and lined and covered reservoir storage will help to protect the South Orange County system. Water transfers from outside of the WMA will also be beneficial to add a layer of insurance with respect to future droughts on the State Water Project or Colorado River system.
Surface Water Development Projects - Limited surface water is available as a potable or non-potable source, as surface flow is required for riparian habitat preservation and key for groundwater recharge. Generally, the heaviest flows in regional watersheds occur primarily in the winter and spring with seasonal rains and snow melt. Groundwater basin recharge rates vary by the geological characteristics of each creek. Finer grained sediment at the bottom of a creek bed provides less opportunity for deep percolation. Therefore, the greatest opportunities for surface water development exist in the reduction and treatment of pollutants to improve water quality for both the affected habitats and groundwater basins. Funded projects such as Santa Margarita Water District’s Gobernadora Basin and Trabuco Canyon Water District’s Groundwater Treatment Plant in are two projects that illustrate the importance of comprehensive surface water development.
In the IRWM Plan, two creek diversion or water reuse projects are included, one at Oso Creek and the other at Aliso Creek. Both projects offer significant benefits to the watersheds by managing and improving the downstream flows to maintain the corridor habitats and to improve the quality of water to be percolated in addition to the harvesting of source water to augment regional supply and reduce delta imported water demands.
Surface water impoundments capture flow from nearly all the major surface water streams. Many of the major surface water impoundments are a blend of natural runoff and imported water. They include:
El Toro Reservoir: El Toro Reservoir is an earth-filled structure owned by the ETWD. It is on a tributary of Oso Creek and is used as a seasonal and operational storage site for the ETWD’s imported Colorado River Water. The impounded water is used for irrigation purposes. Construction was completed in 1967. It has a normal surface area of 21 acres. Its height is 106 feet with a length of 900 feet. Normal storage is 877 acre feet. It drains an area of 0.04 square miles.
Laguna Lakes: The Laguna Lakes are located in Laguna Canyon. The lakes are owned by the City of Laguna Beach and were originally formed by springs arising from a minor fault zone. Laguna Lakes are located inland along Laguna Canyon Road, approximately 6 miles north of Laguna Beach. The lakes are numbered 1 through 3 from upstream to downstream. Lakes 1 and 2 are on the west side of the road and Lake 3 is on the east side. Lakes 2 and 3 were once one lake but are now separated by Laguna Canyon Road. There are approximately 27 acres of open water in the three lakes, plus an un-quantified amount of riparian habitat. The lakes drain a watershed of approximately 5,600 acres. The lakes are filled by seasonal rains and natural and urban runoff. Lake 1 is seasonal, Lake 2 is semi-perennial and Lake 3 contains water throughout most years.
Barbara's Lake: This Lake is a 12-acre spring-fed lake in the James Dilley Greenbelt Preserve, a 173-acre parcel of land in the Laguna Coast Wilderness Park. Located in Laguna Canyon, just north of the Highway 73 toll road, the area forms the north boundary of the 38,000-acre South Coast Wilderness. Barbara's Lake is named in honor of conservationist Barbara Rabinowitsh and is the only natural lake in Orange County. The lake is rimmed with willows, cattails, and bulrush, offering habitat for coots, mallards, and grebes. West of Barbara's Lake, across Laguna Canyon Road, is Bubble's Pond. The pond was named for Lion Country Safari's escaped hippopotamus, who took up a temporary residence there. The trail winds blow through canyons and over hills en route to the south and east shores of Barbara's Lake.
Lake Mission Viejo: Lake Mission Viejo is a man-made reservoir located in northern Mission Viejo. The reservoir is formed by an earth-fill dam across the canyon of Oso Creek, which is part of the Trabuco Creek and San Juan Creek drainage basin. The reservoir is in the foothills of the Santa Ana Mountains, surrounded primarily by private residential communities, and is fed by urban runoff.
Upper Oso Reservoir Dam: Upper Oso Reservoir is located in Mission Viejo and owned by the Santa Margarita Water District. For over 30 years recycled water has been stored in winter prior to irrigation in the summer. The Upper Oso Reservoir holds up to 1.3 billion gallons of recycled water. At capacity the reservoir is 65 feet deep at its deepest point. In December 2012, the reservoir was 140 feet deep at its deepest point, based on information provided by Santa Margarita Water District. It is one of the largest recycled water reservoirs in the County.
Sulphur Creek Reservoir: Sulphur Creek Reservoir (also called the Laguna Niguel Lake) is an artificial 44-acre fishing and recreational lake in Laguna Niguel. It is fed from two sources, one of which is Sulpher Creek itself and one is a storm drain. In the 1950s, the creek was dammed to form Sulphur Creek Reservoir.
The Projects will help protect and develop surface water to ensure sustainable local supplies.
Water Recycling Projects - Water recycling has long been regarded as a cost-effective water supply alternative in Orange County. Recycled water in the County is used to irrigate crops, golf courses, parks, schools, business landscapes, residential lawns, and some industrial uses. Local water recycling projects involve the collection of wastewater that is currently being discharged within the service area, treating that water to a suitable standard for specific uses, and substituting the recycled water for existing or future potable water demands. The projections for expanded development of this type of water recycling are based upon several “institutional assumptions” that vary depending on the end use of the recycled water. Development of recycled water projects generally requires creative solutions to funding, regulatory requirements, institutional arrangements and public acceptance.For example, the Irvine Ranch Water District proposes the Baker Water Treatment Plant (WTP) Project. The Baker WTP Project is a collaborative effort by south Orange County water agencies including ETWD, IRWD, MNWD, SMWD, and TCWD that was initiated to diversify the mix of water supplies to meet the South County’s needs and improve system reliability to provide sufficient water supplies during both planned and unplanned emergency outages of the imported water system. The Project includes design and construction of a new 28 million gallons per day (mgd) membrane surface water treatment plant that will increase water supply reliability for nearly one million people that reside in the south Orange County communities, from Lake Forest to San Clemente. The Baker Plant will be base-loaded and operated on a continuous basis. The project will utilize both local and imported raw waters that cannot be currently used for potable uses. Imported water from Metropolitan Water District’s (MWD) Lake Mathews will be supplied to the plant through the MWD Lower Feeder and the Santiago Lateral Turnout OC-33 via the Baker Pipeline. Alternatively, local runoff water stored in Irvine Lake can also be supplied to the plant via the Baker Pipeline. Irvine Ranch Water District (IRWD) is the lead agency for the project.
Recycled water is an important part of the WMA supply system. The following projects reflect the current recycled water systems in the Region.
The MNWD Phase 5 Recycled Water Distribution Expansion Project – The MNWD Phase 5 Recycled Water Distribution Expansion Project includes the construction of pipelines, reservoirs, pump stations, and service connections. Participating cities include the cities of Laguna Niguel, Aliso Viejo, Mission Viejo and Laguna Hills. This project is part of the MNWD Recycled Water Distribution System and was started in 2012.
The Salt Creek Treatment Plant Water Re-use Project –The City of Dana Point is proposing this project to re-use water for irrigation adjacent to Salt Creek at Pacific Coast Highway. This project is part of a larger project, the Salt Creek Ozone Treatment Plant. The Salt Creek Ozone Treatment Plant provides advanced storm water treatment to reduce bacteria levels in Salt Creek dry-weather flows from the 4500 acre watershed. The project has significantly reduced the number of beach postings.
ETWD Recycling Plant - El Toro Water District Water Recycling Plant is operated by El Toro Water District and is located in the City of Laguna Wood. The plant has a maximum influent capacity of 6 MGD. Wastewater is treated to a secondary to Title 22 standards depending upon the ultimate use of the effluent. In 2010, 4,220 acre-feet of secondary treated effluent is disposed via the SOCWA Effluent Transmission Main to the Aliso Creek meeting Title 22 standards and is sent to the recycled water distribution system.