Updates and News Extension Highlands/Las Posas Road Over eighty people attended the Feb. 8th site meeting . County and City residents objected to the .... Click here for all news updates

Why preserving this area is important

At its headwaters in northern San Marcos, Hedionda Creek runs through a valley of undisturbed habitat, mostly coastal sage scrub and riparian vegetation. The valley is surrounded by the San Marcos Mountains and Owens Peak to the east and south, and unnamed hills and peaks to the west and north. This complex of mountains and creek valley is one of the few relatively large blocks of natural vegetation remaining in the Multiple Habitat Conservation Plan (MHCP) study area (Federal Register, 4/15/99, p. 18628) within the San Marcos area. As such, it is a valuable area to conserve. It supports many sensitive species of flora and fauna.

For almost ten years, the Friends of Hedionda Creek, a group of concerned residents and environmentalists, has been fighting to preserve the Hedionda Creek Valley in northern San Marcos. The area is threatened by development project is due

Detail background information on the environmental issues:

1. The Hedionda Creek Valley has high biological value because of its undisturbed coastal sage scrub (CSS) and riparian habitat. The threatened coastal California gnatcatcher has been sighted on and adjacent to the property to be developed. Also, the endangered least Bell’s vireo has been observed adjacent to the property. The valley teems with wildlife, including mule deer, bobcats, coyotes, and a variety of amphibians, butterflies and birds, including the Cooper’s hawk, a Species of Special Concern. Although the Highlands developer is proposing mitigation measures for the removal of over 40% of the CSS on the site, the fact remains that the wildlife in this valley will be devastated if this project goes through. (The mitigation will be offsite.)
   
   
2. The Hedionda Creek Valley is the headwaters of Agua Hedionda Creek, which flows westerly, until it discharges into Agua Hedionda Lagoon. Agua Hedionda Creek is part of the Carlsbad Watershed, which has recently been extensively studied, and a management plan for the watershed has been developed. (Carlsbad Watershed Management Plan, prepared by KTU & Associates) The management plan calls for protection, restoration and enhancement of undeveloped open space in the headwaters of the watershed that will provide natural filtering capabilities for water runoff control and water quality improvements. Also, it calls for the purchase or transfer into public ownership or control of as many of these wetland resources as possible. This includes the Hedionda Creek Valley.
   
   The Highlands project will fill in over 5,000 liner feet of streambed. Although the developer has proposed mitigation for the impacts, the mitigation measures are vague. Therefore, FHC calls for the acquisition of the wetlands and their watersheds.
   
   
3. A an issue related to the wetlands impacts is the potential for increased pollution of the Creek. Substituting impervious surfaces such as streets, parking lots, driveways, etc. , for native vegetation and its buffering and filtering capacities will lead to increased pollution. Also, the introduction of non-native vegetation in landscaping in the development will lead to increased pollution because of the use of herbicides, insecticides, fertilizers, etc. Agua Hedionda Creek is already highly polluted and is being recommended for listing on the List of Impaired Waters for the Region due to Diazinon and other pollutants. Agua Hedionda Lagoon is already on the List of Impaired Waters. The Carlsbad Watershed Management Plan states, “Waterbodies within the San Diego region continue to be degraded and impaired at an alarming rate.”
   
   
4. The Highlands development requires the extension of a major road, Las Posas Road, along the wetlands. Roads and traffic are devastating to wildlife. The mitigation proposed by the developer in the draft EIR for the damage that this road will do to the wildlife is one 48” culvert under Las Posas Road. A 48” culvert would be totally inadequate for the wildlife in the area, which includes mule deer. The guidelines for the North County Multiple Habitat Conservation Program call for avoidance of roads through wildlife corridors, and where roads must cross wildlife corridors, they should have bridges of at least 20 feet in height to allow deer to cross.
   
   
5. Finally, and very importantly, the Hedionda Creek Valley is a recognized wildlife corridor, connecting two of the important remaining large blocks of habitat in the northern San Marcos/San Diego County area. To the south and east of the Valley lie the San Marcos Mountains, and to the north and west, an unnamed mountain range. The Wildlife Agencies have pointed out that the Highlands project is located at a “pinch point” of remaining natural lands between the two mountain ranges. They have stated, “It appears that the proposed development would completely block this connection ...”

We know that fragmentation of habitat is one of the major environmental concerns in North San Diego County. This proposed development will cut a major open space area in two and prevent wildlife from accessing the creek from the west. The impact on the wildlife will be devastating. The Friends of Hedionda Creek is calling for a 1,000-foot wildlife corridor along the north side of the Highlands property, from east to west. This will allow the wildlife to continue to cross the Valley to the mountains and will permit wildlife access to the creek. FHC also calls for the elimination of roads through wildlife corridors.

These are the major environmental issues involving the Highlands development. There are many other major issues, such as incompatible land uses.

Map and Photos