Section 6 IRWM Region Boundary
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Section 6 IRWM Region Boundary 6.1 San Diego Funding Area Boundary This section addresses the following Reviewer questions: • Does it appear that the IRWM region boundary was based solely on political boundaries? • Does the region boundary appear appropriate? • Does it appear that the IRWM region is structured to maximize opportunities to integrate water management activities related to natural and man-made water systems, including water supply reliability, water quality, environmental stewardship, and flood management? The San Diego Funding Area (SDFA) boundary mirrors that of the San Diego Regional Water Quality Control Board (SDRWQCB) boundary. It comprises approximately 3,900 square miles in the southwestern corner of California. The San Diego Funding Area encompasses most of San Diego County and parts of southwestern Riverside County and southern Orange County. The northern boundary lies in Orange County and is the hydrologic divide that extends from the ridge of the Elsinore Mountains to the coast north of Laguna Beach. The southern boundary is the United States – Mexico international border. The eastern boundary extends northerly along the hydrologic divide formed by the Laguna, Cuyamaca, Palomar, and Santa Ana Mountains located in the Cleveland National Forest. The western boundary parallels the coastline and extends north-south approximately 85 miles to the international border. The 85 miles of coastline include the Pacific Ocean and various bays, harbors, coastal lagoons, estuaries, and river mouths. The natural water resources in the San Diego Funding Area can be classified as inland surface waters, ground waters, and coastal waters. The San Diego RWQCB Basin Plan identifies the beneficial uses of and water quality objectives for the waters in this region. The San Diego Funding Area is comprised of eleven hydrologic units that originate in the highlands and flow west to the coast. These hydrologic units are further broken down into watersheds or hydrologic areas. From north to south these hydrologic units are covered by three IRWM Plans, as shown in Table 6.0. Six of the hydrologic units extend from the coast all the way to the eastern boundary of the San Diego Funding Area, about 50 miles inland. The other five hydrologic units extend some 10 to 25 miles inland from the coast. As shown in Figure 6-1, and discussed in detail in question five, two Watershed Overlay Areas will be managed by a Tri-County FACC Overlay Subcommittee. The Overlay Subcommittee will identify cross-boundary projects and common programs for the San Mateo Creek and the Santa Margarita River watersheds. A 6-1 Section 6 IRWM Region Boundary Most of the streams in the San Diego Funding Area are interrupted in character, with both perennial and ephemeral components due to variable precipitation patterns and the construction of surface water impoundments. Many of the major surface water impoundments contain a blend of natural runoff and imported water, and may be supplemented by reclaimed water. The major hydrologic units in the San Diego Funding Area contain groundwater basins, developed mostly for municipal and agricultural supply purposes. The basins are relatively small in area and generally shallow. Because of the movement of groundwater to the surface and the movement of surface water into the ground, pollutants present in groundwater may be transported into surface waters and vice versa. Land uses in the lower portions of the watersheds often differ from those in the upper watersheds. This difference in land use can translate into differences in water quality and beneficial use problems. The Overlay Subcommittee will address this situation as part of its deliberations and project solutions. The San Diego Funding Area has formed the Tri-County FACC to balance the necessary autonomy of each planning region to plan for itself at the appropriate scale with the need to coordinate among ourselves to improve inter-regional cooperation and efficiency. In addition, the Tri-County FACC will allow for coordination of opportunities to integrate water management activities related to natural and man- made water systems, including water supply, reliability, water quality, environmental stewardship, and flood management. Table 6-1 San Diego Funding Area’s Hydrologic Units1 South Upper Santa Area Watersheds or Orange San Diego HU Name of HU Margarita (sq. miles) Hydrologic Areas County IRWMP IRWMP IRWMP Aliso Creek 9 San Juan Creek 9 901 San Juan 500 San Mateo Creek 9 9 San Onofre Creek 9 Santa Margarita 902 Santa Margarita River 750 9 9 River 903 San Luis Rey River 565 San Luis Rey River 9 Loma Alta Creek 9 Buena Vista Creek 9 Encinitas 9 904 Carlsbad 210 Aqua Hedionda 9 Creek San Marcos Creek 9 Escondido Creek 9 905 San Dieguito River 350 San Dieguito River 9 Los Peñasquitos 906 Peñasquitos 170 9 Creek A 6-2 Section 6 IRWM Region Boundary Table 6-1 San Diego Funding Area’s Hydrologic Units1 South Upper Santa Area Watersheds or Orange San Diego HU Name of HU Margarita (sq. miles) Hydrologic Areas County IRWMP IRWMP IRWMP Rose Creek 9 Tecolote Creek 9 907 San Diego River 440 San Diego River 9 908 Pueblo 60 Chollas Creek 9 909 Sweetwater River 230 Sweetwater River 9 910 Otay River 160 Otay River 9 911 Tijuana River 470 Tijuana River 9 Adapted from basin descriptions presented in Water Quality Control Plan for the San Diego Basin (Regional Board 1994). 6.2 Upper Santa Margarita Planning Area Boundary This section addresses the following Reviewer questions: • Is it clear what the basis and rationale for the IRWM region boundary is? The Upper Santa Margarita watershed is comprised of: Urban and suburban areas of moderate to lower density along the I-15 corridor including the cities of Murrieta and Temecula among others; rural residential and agricultural areas; and forest and open space. The majority of the population and water resources infrastructure has been developed in the urban-suburban and agricultural areas. Through coordination with the US Forest Service in cooperation with the Tri-County FACC, the Upper Santa Margarita Watershed “region” was expanded to the west to include forested open space to the west. This western area does not currently have developed water resources or identified water management needs, but completes coverage of the region—connecting the Upper Santa Margarita Planning Area. As redefined, the Upper Santa Margarita Planning Area fully covers the Upper Santa Margarita and Upper San Mateo watershed areas and related areas as shown in Section 2 and Figure 6-1 of this RAP Application. With the watershed overlay areas the boundaries cover the rest of the watersheds through the Tri-County FACC. The watershed overlay areas allow for integration of the boundaries while reducing governance disruptions between counties and without over expanding the size of the planning area beyond stakeholder’s capacity to participate. This combination leads to the optimum use of existing institutions and planning and integration of water related programs. The stakeholders, the RAC and the Tri-County FACC all agreed to the boundary and process in endorsing and recommending RWMG approve the Tri- County FACC MOU. For a more complete description of the MOU see Section 5.4.2, (page 5-10 of this RAP Application). For more detail on the evaluation of the A 6-3 Section 6 IRWM Region Boundary alternative methods of boundaries and governance, see Section 8.2 (page 8-4 of this RAP Application) and Appendix D of this RAP Application. 6.3 Upper Santa Margarita Planning Area Water Management This section addresses the following Reviewer questions: • Does the region boundary consider multiple water management boundaries? • Does the IRWM region encompass the service areas of multiple regions? The Upper Santa Margarita Planning Area is a significant area as previously described in Section 2 of this RAP Application, and covers a number of water management boundaries, Major service area and water management boundaries include the Eastern and Western Municipal Water District Service Area as well as retail service in the cities of Temecula, Murrieta, and other water providers. Additionally Riverside County Flood Control and Water Conservation District provides flood management and water conservation management service to the area. The County of Riverside manages the Multi-species Habitat Conservation Plan, County parks and Open space and County Public Health which do not directly manage potable water but does manage considerable water related habitat or health and safety concerns. All of these are directly represented by the RWMG participants. Planning Area stakeholders are described in Section 2-x (page 2-x of this RAP Application). Significant involvement from DAC stakeholders such as the Elsinore, Murrieta, Anza Resource Conservation District represented through SAC participation are integral to IRWMP planning, project selection, and implementation. Rancho California Water District (RCWD) took the lead with the County of Riverside and the Riverside County Flood Control and Water Conservation District in development of an IRWMP for the upper portion of the Watershed (Figure 6-1). As shown on Figure 6-2, the IRWM boundary divides the Santa Margarita Hydrologic Unit along the county line and multiple individual hydrologic units are split between the upper and lower watershed. The Temecula Gorge and Santa Ana Mountains just south of the confluence of the Temecula and Murrieta Creeks in the upper watershed serve as a natural barrier between the lower and upper watersheds. Murrieta Creek and its tributaries drain approximately 222 square miles in the northwest portion of the upper watershed. Temecula Creek and its tributaries drain approximately 366 square miles with the upper portion of the watershed and almost all flows from the upper watershed pass through the Temecula Gorge. With respect to political and jurisdictional boundaries, the IRWM boundary encompasses the service areas of multiple federal, state, and local agencies (Figure 6-3).