Old Palo Alto resident Sue Kemp saves water by the cup in her kitchen to use in her garden. When she noticed a fire-hose-sized pipe from Google co-founder Larry Page's construction of a new home with basement continuously pouring water into a storm drain, she was concerned.

Such pumping worries other residents as well.

"Waste on this scale is unconscionable," resident David Stonestrom wrote in an open letter to the City Council in 2008, responding to earlier basement-pumping operations. Stonestrom said he was acting as a concerned resident and not in his professional capacity as a hydrologist with the U.S. Geological Survey in Menlo Park.

Resident Steve Broadbent observed that occasionally the city names such basement-construction projects "green." In a 2008 letter to City Council, he claims such labels are disingenuous given the sizeable waste of water.

City Planning Director Curtis Williams noted that the groundwater isn't tied to Palo Alto's Hetch Hetchy Reservoir drinking-water supply but is from a natural aquifer flowing beneath Palo Alto from the hills to the bay.

A 2008 city manager's report claimed that not all of the water is actually wasted, since much of it is later reabsorbed in regional creek beds. But Broadbent pointed out that Adobe, Matadero and Barron creeks all have concrete bottoms and sides for most of their length -- which prevent water absorption.

Such water waste isn't easily avoided, however, because it's "too large a volume for individual use, and too impractical to capture and reuse for other use," according to the 2008 manager's report.

Civil and Environmental Engineering Professor Yoram Rubin of the University of California, Berkeley, agreed, adding that occasionally such pumped water can be injected back into the ground somewhere else to recharge the aquifer. Yet that has its own danger: It can contribute to flooding in some low-lying areas, he said.