"SAN FRANCISCO -- Riffling through old maps while researching a history project for San Francisco public schools, landscape architect Bonnie Sherk made a discovery: a century ago a creek coursed where two school campuses stand today.
'There was Islais Creek, running where Balboa High School is now,' said Sherk. 'All of a sudden it made sense: the school's cafeteria had been flooding and the basements of homes in this neighborhood flood during heavy rains because they're in this large watershed.'
Two wells have been drilled on the school campuses since Sherk's discovery a decade ago, tapping the hidden creek's water to irrigate community gardens, parks and street vegetation, while hopefully reducing the threat of floods.
Now, as part of an estimated $4 billion sewer upgrade, Islais Creek and other streams that last saw daylight more than a century ago could flow openly once again through neighborhoods of one of the country's most densely built cities.
Such 'daylighting' of urban creeks is being embraced in cities throughout the world. Seattle, Portland, Ore., Yonkers, N.Y., Providence, R.I., as well as Zurich are among many places reopening long hidden waterways. Resurrecting old creeks can help remove hundreds of millions of gallons of storm water from sewer systems each year -- meaning fewer sewage spills and cleaner water."