Existing Conditions and Issues Existing Conditions and 2 Issues 13 Secondary Access Existing Conditions and Issues 14 Santa Susana Pass State Historic Park consists mainly of open space and low- PARK SUMMARY to medium-density residential neigh- The following section summarizes the borhoods. Chatsworth Park North and existing land uses, facilities, and Chatsworth Park South, city parks significant natural, cultural, aesthetic, operated by the Los Angeles interpretive, and recreational resources Department of Recreation and Parks, of Santa Susana Pass State Historic are to the east. Garden of the Gods, a Park. The information was adapted 23-acre park operated by the from the Resource Inventory Mountains Recreation and Con- (Appendix G, under separate cover) servation Authority, is located to the that was initiated for the General Plan northeast of Santa Susana Pass State process and provided the baseline data Historic Park, and lands affiliated with for developing the 1) management Corriganville Park, which is operated zones and 2) the goals and guidelines by the Rancho Simi Recreation and found within the Plan Section of this Park District, are located adjacent to document. the northwestern corner of the Park. EXISTING LAND USE Much of the northern boundary of the The Park’s rugged terrain plays host to Park runs along Santa Susana Pass trail use for hiking, biking, horseback Road, and beyond that is State riding, and most recently added to the Route 118. California Department of list: geocaching. Santa Susana Pass Transportation (Caltrans) and City of Road is used as a recreational bike Los Angeles Department of Public route, as well as a recreational Works right-of-ways exist along these motorcycle route. roadways. 15 Visitors usually come from within a Oakwood Memorial Park is to the east 10-mile radius of the Park, and nearby at the southeast end of the Park. A residents often take advantage of the parcel along the south side of Santa trails to walk their dogs, which state Susana Pass road, owned by the law requires to be on a leash. Church at Rocky Point contains a Organized hikes by local trail groups recreational center and facility called are currently the only known ongoing, KidsFutureNow! Other adjacent and interpretive activity. onsite land holdings and right-of-ways include the Las Virgenes Municipal EXISTING FACILITIES Water District pump station, an under- There are no developed facilities ground Metropolitan Water District within the Park (no parking, camping, metering connection, Calleguas picnic or posted and maintained trail Municipal Water District power facilities). The Park is open for day- generating facility, and Southern use visitors only, and most use either California Edison power lines and street parking or parking lots at towers. The Southern Pacific Railroad Chatsworth Park South. runs east-west through the middle of Santa Susana Pass State Historic Park, ADJACENT LAND USE although a majority of the railroad Land use to the north and west of right-of-way is underground, through Santa Susana Pass State Historic Park the Santa Susana Tunnel. Existing Conditions and Issues NATURAL RESOURCES standards for the following pollutants Environmental Setting or air quality conditions: The Park is located in a rural and sulfates unincorporated portion of Los Angeles vinyl chloride County in the California Floristic visibility Province, Southwest Region, Western The Park is within the South Coast Air Transverse Ranges Subregion. The Basin. Because of its location and climate is considered Mediterranean close proximity to from major urban and fluctuates with the seasons, with pollution sources, the Park often has hot dry summers and mild wet winters. poor air quality. A major portion of the Average annual rainfall is air pollution affecting the Park is wind approximately 45.7 centimeters transported and likely arises from (≈18 in); which falls as rain primarily urban sources in the greater Los in the winter. The mean temperature is Angeles area. As of June 15, 2005, the 16 degrees Celsius (61° F) with an South Coast Air Basin is in non- average high of 23.7 degrees Celsius attainment for particulate matter (both (74.6° F) and average low of PM-2.5 and PM-10), 1-hour ozone 8.8 degrees Celsius (47.9° F). The (extreme), 8-hour ozone (severe), and freeze-free period is from 275 to carbon monoxide (serious). 325 days. Hydrology Air Quality The Park is located within the Air pollutant emissions sources are Los Angeles River Hydrologic Unit. 16 typically grouped into two categories: The Los Angeles River Hydrologic stationary (point and area sources) and Unit consists of 74,622 hectares mobile sources (motorized vehicles). (184,395 acres) with the Los Angeles The U.S. Environmental Protection River being the major drainage in the Agency (USEPA) has established unit. The Santa Susana Pass Wash, ambient air quality standards for the flowing west to east along the northern following air pollutants: ozone (O3) nitrogen dioxide (NO2) carbon monoxide (CO) sulfur dioxide (SO2) lead (Pb) inhalable particulate matter (PM10) Additionally, the California Air Resources Board has also established ambient air quality standards for the six pollutants regulated by the USEPA. Some of the California ambient air quality standards are more stringent than the national ambient air quality standards. In addition, California has established ambient air quality Sandstone Santa Susana Pass State Historic Park border of the Park, is a first order • The Chualar series consist of very stream and the only perennial water deep, well-drained soils that course flowing through the Park. It is formed in alluvial material from generally characterized by a relatively mixed rock sources. narrow stream channel with a steeply • The Gaviota series consists of very incised bank, as it runs through the shallow or shallow, well-drained Park. Additionally, three unnamed soils that formed in material ephemeral drainages, generally weathered from hard sandstone or running west to east, flow through the meta-sandstone. Park (see Figure 2). • The Gazos series consists of Geology and Geomorphology moderately deep to bedrock, well- The Park is located on the eastern edge drained soils that formed in of the Simi Hills. The Simi Hills is a material weathered from sandstone small rocky mountain range on the and shale. northwestern edge of the San Fernando • The Saugus series consists of deep, Valley, located within the Transverse well-drained soils that formed from Ranges. Sedimentary rock is most weakly consolidated sediments. common on the western slopes while Vegetation Communities granitic and metamorphic rock dominate in the east. Elevations in the Initial surveys by CDPR Environ- Park range from approximately mental Scientists identified nine 950 feet to over 1,850 feet above mean vegetation communities (Figure 3) sea level. Topographic relief is diverse within the boundaries of the Park and in some cases extreme. including chamise-redshank chaparral, 17 coastal sage scrub, mixed chaparral, Soils coastal oak woodland, valley foothill The Natural Resource Conservation riparian (southern coast live oak Service has mapped six soil series riparian forest), fresh emergent (Anacapa, Balcom, Chualar, Gaviota, wetland, annual grassland, eucalyptus, Gazos, and Saugus) in the Park. These and barren/rock. soils vary widely in depth, fertility, Chamise-Redshank Chaparral permeability, and other important characteristics. There are no listed Mature chamise chaparral is single hydric soils found within the Park’s layered and generally lacking well- boundaries. developed herbaceous ground cover and overstory trees. Shrub canopies • The Anacapa series consists of frequently overlap, producing a nearly deep, well-drained soils that impenetrable canopy of interwoven formed in alluvium derived from branches with very little herbaceous predominantly sedimentary rock understory or litter. It is adapted to sources. repeated fires by stump sprouting. • The Balcom series consists of Chamise-dominated stands average moderately deep, well-drained soils 1 to 2 meters (3.3 to 6.6 ft) in height, that formed in material that but can reach 3 meters (9.8 ft). Total weathered from soft, calcareous shrub cover frequently exceeds shale and sandstone. 80 percent, but may be considerably Existing Conditions and Issues lower on extremely xeric sites with absolute shrub cover. Mixed chaparral poor soils. supports approximately 240 species of The dominant over story species in the woody plants. Composition changes Park is chamise (Adenostoma between northern and southern fasciculatum). Associated species California, precipitation regime, include California buckwheat aspect, and soils. (Eriogonum fasciculatum), eastwood Common shrub species found in the manzanita (Arctostaphylos Park include chaparral whitethorn, glandulosa), chaparral whitethorn greenbark ceanothus (Ceanothus (Ceanothus leucodermis), black sage spinosus) and Eastwood manzanita. (Salvia mellifera), and purple sage Other associated species include (Salvia leucophylla). Chamise chamise, poison oak (Toxicodendron chaparral is found throughout the Park. diversilobum), laural sumac, hollyleaf Coastal Sage Scrub cherry (Prunus ilicifolia), California buckthorn (Rhamnus californica), Coastal sage scrub systems are yerba santa (Eriodictyon crassifolium), characterized by low- to moderate- and toyon (Heteromeles arbutifolia). sized shrubs with mesophytic leaves, Mixed chaparral is found throughout flexible branches, semiwoody stems, the Park.