Ysidora Hydrologic Area (902.1)
Situated near the border of San Diego County, the Ysidora Hydrologic Area covers a land area of about 28,000 acres. The County of San Diego manages all outfalls associated with the storm water conveyance system for the portion of the Santa Margarita Watershed that lies within its borders (hereby referred to as the Santa Margarita WMA), including the entirety of the Ysidora Hydrologic Area.
Overlapping significantly with Marine Corps Base Camp Pendleton, the Santa Margarita River Estuary delineates the point at which the Santa Margarita River meets the Pacific Ocean. The Estuary is home to a variety of mammalian, fish, plant, and bird species, including the tidewater goby, the California least tern, and the western snowy plover.
The region is protected from most urban and suburban development due to its military land use; however, water quality conditions further upstream still exert significant pressures on the Ysidora system. Accordingly, land within the sub-watershed is predominately military lands (89%), other land uses being residential (4%) and agricultural (2%).
Despite ongoing efforts by the County of San Diego and Riverside County copermittees, the Ysidora Hydrologic Area contains several water bodies that have been listed as impaired under Section 303(d) of the Clean Water Act. These include the Santa Margarita River Lagoon, which is considered eutrophic, and the lower Santa Margarita River, listed as impaired for enterococcus, coliform bacteria, phosphorus, and nitrogen.
Which Marine Corps Base is located in the Ysidora Hydrologic Area?
De Luz Hydrologic Area (902.2)
The largest Santa Margarita system within the jurisdiction of San Diego County, the De Luz Hydrologic Area covers a land area of nearly 41,000 acres. As there are no overlapping municipalities here, the County is the only jurisdiction within this portion of the De Luz Hydrologic Area.
Undeveloped lands and open spaces make up the largest share of the De Luz Hydrologic Area, at forty-two percent (42%). In addition, Marine Corps Base Camp Pendleton comprises about thirty-one percent (31%) of the system’s area, followed by residential lands at fourteen percent (14%) and agriculture at twelve percent (12%). The system also contains a small fraction of the 4,340 acre Santa Margarita Ecological Reserve, home to thirty (30) miles of protected riparian habitats alongside Santa Margarita River.
A number of water features located here have been singled out as impaired under Section 303(d) of the Clean Water Act. For example, the upper reaches of the Santa Margarita River have been noted as impacted by phosphorus and aquatic toxicity. Similarly, Rainbow Creek was listed for nitrogen, phosphorus, iron and sulfates.
Santa Margarita Ecological Reserve encompasses how many miles of protected riparian corridor?
Pechanga Hydrologic Area (902.5)
Riverside County copermittees are held responsible for most of the municipal separate storm sewer systems (MS4s) in the Pechanga Hydrologic Area, although the County of San Diego manages the storm water conveyance system in the 1,280 acres within its jurisdiction.
With undeveloped and open space lands constituting ninety-nine percent (99%) of the land area, the Pechanga Hydrologic Area remains largely in its natural state. Because such a small portion of the Pechanga system is within San Diego County, most impaired water bodies are monitored by Riverside County copermittees.
The majority of the Pechanga Hydrologic Area lies within which county?
Aguanga Hydrologic Area (902.8)
Located near the upper reaches of the Santa Margarita WMA, the Aguanga Hydrologic Area encompasses approximately 20,000 acres and about sixteen percent (16%) of the area within San Diego County’s jurisdiction. No additional municipalities are contained within this portion of the sub-watershed, so the County of San Diego is the only permittee in this area.
Land usage in the Aguanga Hydrologic Area parallels that in the Pechanga Hydrologic Area. The system is almost completely untouched, with undeveloped lands and open spaces constituting ninety-nine percent (99%) of the land area.
Which is the sole jurisdiction within the Aguanga Hydrologic Area?
Oakgrove Hydrologic Area (902.9)
The Oakgrove Hydrologic Area encompasses about 36,000 acres of land in the headwaters of the Santa Margarita WMA. As is the case with its counterpart hydrologic areas, the County of San Diego is the only jurisdiction here. It remains mostly undeveloped, agricultural and residential land areas constituting only about seven percent (7%) each of the system.
Where is the Oakgrove Hydrologic Area located relative to the rest of the Santa Margarita WMA?
Integrated Natural Resources Management Plan. Rep. N.p.: Marine Corps Base Camp Pendleton, n.d. Marines. Marine Corps Base Camp Pendleton, Mar. 2012. Web. <http://www.pendleton.marines.mil/Portals/98/Docs/natural2012.pdf>.
San Diego County MS4 Copermittees. 2008. Santa Margarita River Watershed Urban Runoff Management Program (WURMP). Final, March 24, 2008. Submitted to the San Diego Regional Water Quality Control Board by the County of San Diego.
San Diego Regional Water Quality Control Board (San Diego Regional Board). 2016 (August 5). Basin Plan. San Diego, CA. Available: http://www.waterboards.ca.gov/sandiego/water_issues/programs/basin_plan.
State Water Resources Control Board. 2010. California’s 2010 Clean Water Act Section 303(d) List of Water Quality Limited Segments. Approved October 11, 2011. Sacramento, CA: State Water Resources Control Board.
Upper Santa Margarita Watershed Integrated Regional Water Management Plan Update. Final, April 2014. Submitted to the San Diego Regional Water Quality Control Board by the County of Riverside, the Rancho California Water District, the Riverside County Flood Control and Water Conservation District, and the Stakeholder Advisory Committee.
Whether you become involved in the public process or you simply take steps to limit your own water usage in and around your home, you can become a part of the solution.
Think about replacing sod and other water-intensive shrubbery with drought-tolerant landscaping. As a result of the drought, many jurisdictions and water agencies actually offer rebates and other incentives to remove natural turf and install rain barrels and other water capture devices. Not only will this save you money up front, but it will also reduce your monthly water bill! Keep in mind that irrigation runoff from your property is prohibited and can result in a fine.
Limit car washing and power-washing of building exteriors as much as possible. If your vehicle is in need of some TLC, then consider taking it to a certified car wash. If you are on a budget, then wash your car over permeable or unpaved surfaces, allowing any excess water to be absorbed into the soil instead of running into storm drains.
Dispose of pest waste appropriately. When taking your dog for a walk, make sure that you always have a bag on hand so that when nature calls, you are ready. This will help prevent bacteria and pathogens that can cause illness from getting into our waterways.
If you have some free time and don’t mind getting your hands a little dirty, many conservancies and foundations host clean up events for local creeks and lagoons. Please see our calendar to learn more about what events are being offered in your area!
Don’t litter! Trash on our roadways and in our yards has a tendency to make its way to creeks, rivers, and ocean waters during rain events. Even consider carrying a bag with you to collect litter as you take your morning or evening neighborhood stroll.
Implementation and adaptation of the Water Quality Improvement Plan is an ongoing process and as always, public input is encouraged. Meetings that are open to the public are posted in a timely manner to allow for public involvement. If you are interested, please check out our calendar for upcoming meetings.
If you observe any discharges of water that you believe may be illicit, then do not hesitate to report it by means of our pollution reporting page.
And lastly, do what you can to spread the word! Sometimes the most effective strategy is the simplest one. Now that you are a water quality expert, we are relying on your help to educate your coworkers, family, and friends.