Their 275,000 acre-foot reservoir as delineated on a map by Boyle Engineering (88 billion gallons) will cover 65 % of the acreage of Tonner Canyon including all of the riparian area and much of the canyon slopes which are covered by walnut woodland, oak woodland and coastal sage scrub habitat. The canyon would need to be bulldozed since decomposing organic material is not allowed in this kind of reservoir

A 275,000 acre-foot reservoir will require a 400 foot high dam to be built immediately upstream of the City of Brea and within yards of the Whittier-Elsinore Fault, a major seismic feature in southern California. If this reservoir were built and if it ever failed, we would be picking up a large swath of Orange County from the beaches down to Mexico.

A geologic map of Tonner Canyon shows that both sides of the canyon, including the dam sites, are covered with deposits designated as seismically induced landslides, further evidence of both the earthquake potential and the inherent instability of Puente Hills slopes.

One of the factors in the determination not to build the Auburn Dam in Northern California was the occurrence of reservoir-induced earthquakes at Oroville following construction of the dam there. These earthquakes were noteworthy because Oroville is situated in a region of low seismicity. Reservoir-induced earthquakes were investigated after that earthquake by USGS and determined to be a valid hazard associated with building large reservoirs near strike slip faults. The Whittier-Elsinore Fault is a highly capable strike slip fault which already poses a substantial earthquake threat to the urbanized area on top of it.

In order to take full advantage of the on going power shortage and rate volatility facing California, Industry's most likely power plant scheme would involve a pumpback concept between two onsite reservoirs. Building two small reservoirs instead of one large one would reduce the storage volume (only one reservoir could be full for a pumpback option) to less than 15% of the storage, substantially defeating the purpose of reservoir construction.

The reservoir will be one-third the size of Diamond Valley Lake, recently built by MWD at a cost of more than $2 billion and which was sold to MWD customers as the ultimate reservoir needed to assure reliable storage capacity south of the Tehachapis. Industry's reservoir, which involves much greater construction problems, and less economy of scale, would likely cost more than $1 billion.