After the Storm
August 28, 2013 by Yugen
Over the weekend, we experienced the heaviest rain fall since the storm that followed the fire. In fact, Tenshin Roshi who was present for part of the storm thought it was some of the heaviest rain he has ever seen at Mountain Center. The good news: we incurred almost no damage.
He had prior warning that the storm was coming through, so we had time to prepare. It was the tail-end of a tropical storm and there were fears earlier in the week that it was going to hit even harder than it eventually did. We cleared the entire parking lot, moving vehicles to higher ground or using them to evacuate. Anything that was at risk of being caught in debris flow was moved to higher ground. We dug out the stream bed running by the kitchen and Buddha Hall with the tractor, so there was a deeper and wider channel for the water and debris to flow through. Above this channel was another channel about 20 feet long and 5 feet deep which we dug a few weeks ago.
When the rain fell, it fell quickly and heavily. As predicted, it fell too quickly for the ground to absorb it, so sheets of water and mud slid down through the valley. The water and debris was caught in the deep channels we dug by the kitchen, and once these filled, the water flowed through the stream bed and followed the diversion we created to take the water behind the hogan (the octagonal building near the office), rather than in front of the office. The rationale here was clear: if the water and debris flowed through the old stream bed, the office and possibly the workshop would be at risk. For this reason, we diverted the stream bed away from these buildings.
There was no damage to the parking lot or any of the buildings and all the debris and water flowed through the stream bed as we had hoped. There will be more tractor work to re-dig some of the trenches along the stream bed and also some of the trenches along the side of the main road which got filled in by debris during the storm. Compared to the last post-fire storm, there was virtually no damage that occurred. The measures we already have in place worked this time.
This storm was good lesson for us in how to prepare and to see how the water and debris flow. Although the rain was heavy, it was not prolonged, lasting only a few hours. We certainly need to look at what might happen during prolonged storms, as areas which haven't yet experienced debris flow still could in the future under different conditions. We have Robert Hewitt from the NRCS (Natural Resources Conservation Service) coming on Friday for an on-site inspection. The NRCS did not receive any extra funding from the government to help with the post-fire clean up, but they want to help in ways that they can, and for us, an on-site inspection will be very useful. Depending on what Robert finds, it will give us a good sense as to whether the geo-technical engineer who is working with us would have good reason to come down for an inspection as well. Robert may be able to provide recommendations as to what kind of barriers we could use and in which locations in order to protect the various buildings.
Reid, the geo-technical engineer, has been speaking with a geologist at the Forest Service and has already been given some useful information in terms of what happened during the storm immediately following the fire. It looks like the BAER report which we were waiting on immediately after the fire (which is still not a public document yet) will not be of that much use anyhow. The broad brush recommendation may not really help us in the way that the more detailed modeling from the USGS (United States Geological Survey) will. The preliminary findings are going through the process of being checked and approved before being released, but Reid hopes to be able to have access to some of this information soon. The USGS also want to install a rain gauge on our property to see how well their modeling data holds up over time. This is great for us, as it will help us with our safety assessments during storms. Certain amounts of rainfall over a period of time can lead to flash flooding and debris flow, and a gauge will help us determine this more accurately. With the residents evacuated from Saturday night through Wednesday morning (today) it felt like it did during the fire—not knowing what we might return to find. It was a great relief to discover that there was virtually no damage to the center and the work we have already done was enough to avert further disaster. Over the next few weeks we will be reinforcing and adding to the channels and diversions we already have in place, and hopefully the visit on Friday from NRCS will give us more of a sense of direction as to how best continue with the work.
We have more storms forecast for this week, but none are predicted to be heavy and there are no current flash flood warnings for the area, so we aim to remain at the center this week and continue with the schedule.
Tom, our plumber, staked the provisional work done at the well site in with metal stakes to prevent it from being washed out during the storm.
The channels that we dug before the kitchen along the stream bed.