New Santa Clara River Management Plan Offers Effective Strategy : Conceived by Newhall Land, its principles could be applied elsewhere in Southland to protect waterways and balance competing interests.

Southern California’s rivers frequently are the source of controversy over such issues as environmental protection, development, recreation, open space and flood control. Witness the longstanding struggle over the future of the Los Angeles River.

Fortunately, the just-completed Natural River Management Plan for the Santa Clara River offers a new, more effective strategy for balancing competing interests and protecting Southern California’s rivers. This management plan covers 15 miles of the Santa Clara River’s main channel and tributaries in the Santa Clarita Valley. It was prepared by the Newhall Land & Farming Co., which is the largest owner of the Santa Clara River in the area covered by the plan.

The U.S. Army Corps of Engineers, which regulates any encroachments on the nation’s rivers, requested that Newhall Land prepare a comprehensive long-range management plan for the Santa Clara in 1987 as a condition for the issuance of a permit for bank-stabilization work.

How did Newhall Land forge a consensus among various interests to prepare this unprecedented management plan? And what lessons does its creation offer other communities that want to protect the environment and guide appropriate development along their own rivers?

The Santa Clara River maintains much of its attractive natural state in the Santa Clarita Valley. Its width varies from 300 to about 1300 feet. Its banks and bottom are home to a host of aquatic, bird and mammal species: fish, frogs, coyote, bobcats, deer, rodents and many birds, including California songbirds, hawks, herons, cranes and ducks. The river also supports a wide variety of riparian plant types: cottonwoods, willows, cattails and other riverine species.

As growth entered the Santa Clarita Valley in the 1960s and 1970s, several jurisdictions carried out then-standard flood control measures on a few portions of the Santa Clara River. For example, 2.9 miles of the south fork were “channelized,” or rebuilt with concrete bottoms and sides like the Los Angeles River’s.

By the 1980s, however, various public agencies began to recognize the drawbacks of such flood control measures. Channelization obliterated native flora and fauna, limited recreation and open space uses and eliminated opportunities for ground-water replenishment.

Forging a consensus among different interests to create a balanced, workable management plan faced many challenges. Some agencies want to preserve as much of the river’s wetland habitat as possible, while others have the duty to minimize flood hazards.

Newhall Land’s team of consultants (which included engineers, flood control specialists, biologists, ichthyologists and environmental planners) found a way to reate this consensus. After considerable research and analysis, the planning team challenged longstanding premises about river management that assumed that unless the river bottom was cleared regularly, vegetation would eventually form an impenetrable wall and block storm waters much as a dam, causing the river to flood nearby land.

If that thinking had really been correct, the natural portions of the Santa Clara River should already have been choked with vegetation. But they weren’t. The winter storm runoff opened channels through the vegetation, reducing the flood risk in a natural, non-invasive manner. Water, as always, found its own way and naturally cleared only the vegetation that had become too restrictive.

With this finding, the planning team used the natural channel as the major flood-control device in the Natural River Management Plan. All natural river processes would continue to occur, such as high winter flows, low summer flows and the meandering of the stream bed. Where levees are required to meet flood control criteria and protect adjacent existing or planned improvements, they would be as near the river banks as possible, leaving most of the channel in its natural state with the vegetation unaltered.

Under the Natural River Management Plan, only 4.6% of the 1,300 acres between the river banks in the study area would be permanently impacted. Moreover, any natural land lost to levee construction would be replaced through replanting of areas of a similar size.

The Los Angeles County Department of Public Works would save money,because the management plan meets flood control objectives and would eliminate routine vegetation removal. L.A. County and the city of Santa Clarita would be able to fulfill their general plan goals to create parks, trails and other recreational facilities along the Santa Clara River.

The river plan would simplify and streamline the permitting process for the Newhall Land & Farming Co. by providing an efficient administrative procedure for implementing projects along the river. Its extensive environmental analysis reduces the need for further studies on subsequent projects.

At present, the U.S. Army Corps of Engineers is processing details of the Natural River Management Plan and additional environmental analysis. The anticipated approval date is December.

Preparation of this plan has not been easy. But the time (nearly a decade) and money that have gone into this work have proved to be a wise investment. The environment, private property rights, development and government are all winners. In coming years, other communities in Southern California and across the West can adopt this natural river concept to guide the protection and development of their own seasonal rivers.