The oaks in Stenner Canyon are old and stately living things, but they stand for something much greater: the ageless system that literally holds the canyon together. The trees marked for destruction occur in riparian (streamside) zones, vital and fragile areas where countless species interact.

The installation of the DWR pipeline, where it passes through open meadows, can have minimal effects. Its presence beside Highway 101 in the Nipomo area is hardly noticeable. But where it cuts a broad swath through streamside forest, where the trees will n ever be allowed to grow back because of their invasive, entangling roots, it promises to do irreversible damage.

A walk along the banks of Stenner Creek shows natural erosion and land slippage due to flooding and stream meandering. If the pipe is laid in the proposed course, disruption will certainly be made worse. To bulldoze the oaks and other large plants, whose roots hold the streambanks together and prevent erosion, is ill-advised. If the pipeline is undermined or broken by streamcourse changes, costly repairs and additional public works will be needed, possibly without end. The scenic appeal of the area will b e further harmed, and the resulting erosion and siltation could damage natural and human systems the whole length of the stream.

Worse yet, since the pipeline water will be already chlorinated, spillage and ventings for the purpose of repairs and maintenance could kill the fish and other species in the stream. During the dry season, this could comprise the major volume of water in the creek. Releases farther from the stream would likely have less toxic effect.

Stenner and Poly Canyons, as natural laboratories used for instruction in a State institution of higher learning, deserve special consideration and preservation. Besides multiple agricultural uses, the streamside trail is a favorite of mountain bikers. It seems likely that this recreational use of the area will be disrupted long after the pipeline is laid, if not permanently.

The pipeline route, some say, was chosen from afar in Sacramento, using maps that did not adequately show the presence of streams and vegetation. Or it may be that the pipe was put in the tree-lined canyon bottom to hide it from view. In any case, there a re alternate routes that don't pass through fragile streambanks andthe trees that hold them together.

If the pipe is laid through a higher meadow route, it should be planned carefully to avoid erosion that would affect downhill areas and be visible from afar. Very likely the university's construction planners and bio-science experts can suggest improvemen ts or even savings. The ability to permit surface vegetation to grow back quickly should make the open route far less damaging to the canyon system as a whole. Let's work to find the best solution.

By: Leonard Carpenter. Send comments to Leonard's e-mail address.