Expert Clarifies Some Groundwater Beliefs
Underground rivers, perhaps created by gold mining operations in the 1850s, have long been rumored to run deep beneath ridge communities.
"That's folklore," exclaimed Toccoy Dudley, a groundwater expert for the Department of Water Resources in Redding.
"I hear stories like that all the time," he said. "They don't exist."
Dudley was emphatic about exploding that, and other ridge water myths, in a presentation to Paradise Irrigation District officials Wednesday.
He said wells may never be a reliable source of water on the ridge during drought periods.
Traditionally thought of as tools for drought relief by the PID and Del Oro Water Co., Dudley said existing wells, and those planned for the future, should be operated at capacity during rainy periods- saving stored water for dry months.
"We need to learn to think outside the box," Dudley said.
He said it would be unusual for a well not to recharge itself from ground water over time, but noted that the quality of well water can be seriously compromised by over-pumping.
The hydrology expert said groundwater on the ridge is an issue no one has looked into much.
He noted, however, that basic geology works against high producing wells in Paradise.
"Wells here must rely on horizontal fractures in rock that can carry percolated water from the ground to a well shaft, "he said.
"Drilling on or near a fault line can increase your chances of a good well," he said.
Del Oro completed a new well in Paradise Pines last summer and claims to be drawing about 850 gallons per minute on a limited pumping schedule.
PID signed at $16,000 contract last week to complete a test hole for a new well it plans off Elliott Road east of Nunneley.
Dudley said continuous pumping through an extended drought is the only way to really test the reliability of a well.
One water customer wanted to know if pumping wells on the ridge has any affect on underground water conditions on the valley floor.
"None whatsover," Dudley said, defusing another widely held belief.
He estimated that up to four million gallons of water runs down the hill from Paradise each day.
"Almost all of it winds up in Butte Creek Canyon," he said. "Very little runs to the valley floor."
Dudley stated that conditions for ground water storage in the northern Sacramento Valley- an area stretching from the Sutter Buttes to Redding- may be better than anyone knew.
"We found a whole bunch of resources we didn't know we had," he said.
He referred to a bulletin DWR was due to issue by the end of next year, but will now be delayed because of emergency studies the department did last summer in the Klamath River Basin.
He said that new information on the Sutter Buttes and Stony Creek alluvial systems may point to promising new sources of water.
Though Tuscan rock formations are known to have traveled two-thirds across the valley floor- with some found as far west as Corning- Dudley said groundwater is still remarkably easy to find there at depths less than 100 feet.
He said some wells dug to depths of 1000 feet or more in the valley have tapped into artesian wells.