No Mitigation Possible for Hidden Creeks Project Ecological Disaster Planned for Santa Susana Mountains

by Garrett Weinstein, Project Analyst for the Mountains Recreation and Conservation Authority
This article is a follow up to the February 2014 article by Paul Edelman,"Environmentally Disastrous Gated Community Given First City Green Light in Browns and Mormon Canyon Core Habitat, Santa Susana Mountains"
(See helpful map links at the end of article)

Examined up close, the Hidden Creeks Estates gated community, proposed to be constructed at the headwaters of the L.A. River in Browns Canyon, next to Michael D. Antonovich Park, offers far less to the community than what it will take away. The planned site for this 188-unit tract housing project is a highly visible plateau in between Browns Canyon and Mormon Canyon Creeks in the Santa Susana Mountains. Currently, this land is zoned for 33 homes. By necessity, this would require the extension of Mason Avenue westward from Porter Ranch, and through a mountainside and across Mormon Creek, in order to provide road access to this otherwise remote site.

The Environmental Impact Report (EIR) for Hidden Creeks either deflects from or outright ignores the real impacts of the project to the quality of the surrounding habitat, and the impacts to the water quality of a significant tributary creek system of the Los Angeles River. This is because it is simply not possible to provide adequate mitigation for the numerous adverse impacts that would result from the project. The developer is legally required to provide mitigation for all such "significant impacts" under the California Environmental Quality Act.

Mitigation, in the environmental sense, means compensating for the impacts of a project, such as replacing lost natural resources, or providing benefits to the public that outweigh what is being lost. Some of the severe environmental impacts that Hidden Creeks would fail to mitigate for include:

  • The grading and re-compaction of more than 150-acres of habitat on the project site. This is necessary for the developer to stabilize the slope of the ancient landslide that comprises most of the property. The developer was well-aware of this condition before the property was purchased.
  • The offsite grading of 9 acres of natural habitat and stream habitat in open space that will soon be dedicated as public open space to the City of Los Angeles. This particular breach of the public trust is discussed more below.
  • Increased fire danger from extending urban development further into the already fire-prone wilderness of the Santa Susana Mountains. Incredibly, the developer is claiming that Hidden Creeks will increase the fire safety for the community of Porter Ranch.
  • Increased urban run-off, a source of pollution, into Mormon Creek, a tributary of Browns Canyon Creek and the Los Angeles River.
  • The removal of 400 native trees. Though many of these trees will be replaced per LA City's Protected Tree Ordinance, the replacement trees will take decades to reach maturity.

The most egregious threat from Hidden Creeks is the breach of the public trust that the project applicant, Texas-based Forestar USA, is quietly asking the City of LA for. Located next to the Hidden Creeks site on the east, and encompassing part of Mormon Canyon Creek, is 80 acres of wildland and trails, slated to be dedicated to the City as open space by the Porter Ranch Development Company as part of the Chatsworth-Porter Ranch Specific Plan approved in the 1980's.   The primary Hidden Creeks property sits on an 11,000 year-old landslide. The developer has to essentially re-grade most of the property to build there.  The bottom of the slope is located on the eastern adjacent property, which is currently owned by the Porter Ranch Development Company. Porter Ranch Development Company is in the process of dedicating part of that land to the City, per their development agreement.  Stabilizing the slope for Hidden Creeks would require grading over 9 acres of this green future public land, right to the edge of Mormon Creek. If the City does not grant permission for this grading on public open space, the developer cannot intensely develop Hidden Creeks Estates as planned. (Construction of the 33 homes the site is currently zoned for may still be possible.)

A public outcry will be necessary to convince the City Council to prevent this. The Tract Map Exhibit (#3 linked below) shows the developer’s plan to grade on property that doesn’t belong to them. Map #4 (also linked below) shows a close up of the open space that the developer intends to grade.

The developer, Texas-based Forestar USA, is asking the public to accept that a mere 19-acre park with softball fields, and weakly supported claims of wildfire protection offer sufficient public benefits to offset the impacts of their project. A general plan amendment, zoning changes, and annexation by the City (the property currently exists in unincorporated LA County) are among the numerous entitlements and exemptions that are being requested to build Hidden Creeks Estates. A project of this scope that offers so little to the greater community is clearly against the public interest.

There are several City hearings left to go before Hidden Creeks can finalize its development agreement with the City, however, final approval rests with the Los Angeles City Council. You can contact your Council office to voice your opposition to this environmentally disastrous project. It would be especially appropriate to contact Councilmember Mitch Englander (CD12), as the project is in his council district. (When requesting more information from the City Planning Dept. or sending in comments, the following Case Numbers will help: CPC-2005-6656-AD-GPA-ZC-DA, VTT-68724, and ENV-2005-6657-EIR.)

Editor's addition:

To quote Paul 's Edelman of the SMMC's February article: " The environmental documentation for the Hidden Creeks Estates Project (ENV-2005-6657-EIR) is unforgivably flawed. How can grading more than 150 acres of the Santa Susana Mountains and Upper Los Angeles River watershed not be considered a significant impact?" "The Final EIR reenters the pre-California Environmental Quality Act (CEQA) dark ages by concluding that 7 million cubic yards grading (of 150 acres), extending a four-lane road three-quarters of a mile into core habitat, and eliminating over 400 native trees is a mitigatible biological impact.":

VIEW MAPS OF HIDDEN CREEK AREA & PLANS links to area maps #1 & #2

Map #1  Good map to show the proposed HC project and the public lands surrounding it.

Map #2  

Map #3

Map #4 This map shows how close the grading will come to the Mormon Creek stream