HUGE THANKS TO REBUILDING TOGETHER: OAKLAND, Rachel Matthews, Paul Radliff, and to the foresight of Landscaper Anders Schmidt.
In 2006, Paul Radliff of Pulte Homes, fell in love with one of our rescue squirrels and made his best argument to the leadership of Rebuilding Together: Oakland to help our struggling grassroots wildlife rehab center. Squirrel Magic prevailed and our small animal rescue center was awarded a grant of over $50,000 worth of materials and labor to renovate our facility. Then the experts showed up and told us how things would go.
Right away they identified a severe erosion problem affecting the foundation of the main building – a house which has served as the educational center for Yggdrasil Urban Wildlife Rescue over the course of nearly five years. The Yggdrasil Urban Wildlife Rescue center is located at an Oakland Hills location, on a 30% percent slope of mostly clay mud. The experts saw that water and time had worked some real mischief on the foundation, especially down slope! In places, there was air holding up the concrete sill – One could poke an arm under this into the basement! On the up slope, water was flowing under the foundation with each rain, washing away more dirt from beneath the foundation. Their solution? A system of cascading terraces formed by Soil Retention Co. designed interlocking soil retaining blocks to redirect the water flow away from the foundation, plus multi-tons of concretized gravel which would fuse at the first rains. Lastly, we would cover the downslope with erosion resistant actinia groundcover.
The property owner gave the go ahead and the crew got to work. And when they were done, the question remained; How would all of this perform in the very Real World of a mushy hillside where thousands of Redwoods once stood shoulder to shoulder against the elements, mighty sentinels only a memory now. And also, only 1.3 miles away, the great sleeping dragon – the Hayward Fault – quivering in it’s ancient sleep, one day to awaken in a colossal shudder…
The winter of 2006 was the first test – and the terraces worked BEAUTIFULLY! In pelting rains te cascades of water were being diverted away from the foundation of the house and flowing down the slope safely, not budging the man-made stones in the sl
ightest. No mudflows here! But what about earthquakes? How would these stones and concrete and gravel hold up against a power that can lift up mountains and sink cities?
Over the next few years we got an answer of sorts, nothing conclusive – yet. A flurry of quakes in the 3-4 Richter range quite nearby didn’t disturb these stubborn little retaining walls in the least bit. And
the house they were helping to hold up remained
dead vertical. (Tested this with a carpenter’s level after each earthquake!)
Now, during the Storms of 2009, we have seen 4.5 inches of rain in the last 24 hours. The soil is supersaturated. Trees are falling all around us. It s at these times that we worry, remembering the mudslide that had blocked Skyline Blvd. back in 2006, one block uphill from us. But quickly, the trying night was over and we went to survey the damage….
NONE!
The walls and terraces had done their job, and the massive rains had been deflected downhill and away most successfully! Four and a half inches of rain had been laughed to shame and all of the outdoor Rescue cages were in good operating order.
The work goes on.
Paul, Anders, Rachel and Rebuilding Together: Oakland – BIG THANKS! You got it right!