Publication Date: Wednesday Oct 15, 1997

A Sand Hill field study

Advocates for both sides of the Sand Hill issue have properly emphasized the special value of the San Francisquito Creek riparian corridor.

In the debate over Stanford's Sand Hill Road project, environmental issues have been surfacing with increasing frequency and intensity. That is not surprising: these issues matter, and our community is blessed with people who care for their environment and invest generously in preserving it.

As environmentalists and environmental scientists, we would like to add a few points--not in the interest of supporting any position in the unfolding debate, but in the hope that the conversation can proceed based on sound assumptions.

Advocates for both sides have properly emphasized the special value of the San Francisquito Creek riparian corridor. Such corridors--recently the subject of a local study by Steve Rottenborn at Stanford's Center for Conservation Biology--are especially important habitats. They are biologically rich, housing unique streamside vegetation and the highest levels of avian biodiversity that can be found in most urban and suburban settings. The Stanford study, and others, demonstrate that the critical factor in retaining that richness is the opportunity for the stream to meander, creating sandbars on which native trees (willows, cottonwoods) can be established.

San Francisquito Creek has, unfortunately, had a history of being channeled for flood control purposes and of aggressive, uncontrolled building right up to its banks. It still has significant environmental values, of course, but these have been sharply limited by past development. By comparison, the Stanford plan allows generous setbacks that will not add to the problems in this area. Construction at the bridge site, it is argued, may produce downstream siltation problems. Whether these would, on net, be adverse is uncertain; but we agree that construction work at that site, and its potential downstream impacts, should be carefully monitored. In our judgment this prospect has been carefully considered in the EIR.

The open field between Oak Creek and the Shopping Center has also received a good deal of attention, especially from opponents of the project. Plainly, an open field--any open field--is an aesthetic asset in an area much of which has been built up. It is important, however, not to confuse this with its value as a biological resource. The field has little or no native vegetation; it is dominated by European grasses and weed species. In this respect it is much like other open spaces on the campus and in the foothills; it is neither native nor unique. Stanford's plan spares substantial open space near the creek border, and the university should be urged to devote that area to efforts at restoring native vegetation.

Strong (even emotional) claims have also been made about the field's status as a feeding resource for Great Blue Herons because they are occasionally seen there. In fact these herons are highly successful predators, capable of shifting their feeding grounds and favorite prey items depending on what is abundantly available. In years when vole populations erupt in the Flood Control Basin, the herons are there in numbers; when ground squirrels on campus are an attractive source they are here--in the eucalyptus grove, on the hill sites, even on the Campus Drive median strip. And independent of such special attractions on land, they hunt fish and frogs in Searsville and other freshwater lakes, or a variety of aquatic and semiaquatic prey items in the Baylands.

In short, the field offers no special status as a biological resource. We have no wish to belittle other values that opponents of the Stanford project have claimed for it. We do think, though, that environmental arguments for or against such projects ought to have a sound and solid science base.

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