We’ve had a deluge in the past week- the typical hard rain that’s been the new norm here at EEC. In this case, the hard rain came down for 48 hours strait, after a month of rain before that. With the ground already saturated, water is now sheeting off every surface, ganging up into raging torrents as it rushes towards the swollen rivers.
The Snoqualmie is over her banks again, and like all rivers in flood stage, she is reeking havoc on bottom land farms and causeways, which connect our small town to the city. Traffic in and out of Duvall has been stressful, and backups throughout the county began to expand as the waters rose. We’ve been in major flood stages twice this week. Mudslides are also taking their toll on major throughways. Transportation backups and inaccessibility will continue to challenge our social normality going forward. Weather dictates all, and we’re in for continued wet deluges and more and more flooding in the years to come.
Our catchment pond is almost to the outflow pipe. It has not crested yet, and may not- but we installed a Pegasus unicorn to bring the magic. Seeing the water collect so brilliantly across the property, preventing any major sheeting, is very rewarding. At least our work and living spaces remain dry. In the woods and along the creek, things are flowing in wild torrents, and luckily, we have a creek to direct flow into, rather than our driveways, though some were still water parks during the worst flooding.
Major weather events are a time to really observe your landscape. At EEC, we’re taking notes on areas of erosion, flooding, good water directing and catchment, as well as seeps, springs, and seasonal creeks. The flooded road above is rare, but would be mitigated by a culvert. The property above is mostly lawn, which created the sheeting water abundance at the bottom of the slope, where my road comes across, creating a dam. At a horse property I work at, the same lake build up is happening for the same reason.
Planning direction for high flow events here in Western Washington is mandatory. Though many people are unaware of the county’s legal requirements for proper surface water retention and redirection. It’s a novel and a half, so I get why most people in King County are clueless about the laws. BUT, they are there, and addressing surface water runoff ensures less flooding in your neighborhood. Imagine if all that water in the flooded arena above burst through the causeway holding it back- thousands of gallons would suddenly flood into an already taxed stream nearby, ushering a flash rise in the already flooded lowland, perhaps causing additional damage.
Another major issue in heavy rain events involves erosion. In worst cases, landslides happen, causing massive soil movement, usually in a down hill direction, incurring the loss of stable slope and degradation of hillsides. If you live up hill of these disturbances, you’re likely to experience future failures in your own slope. Sometimes smaller erosion problems, like washed out roads, plagues land owners. Pictured above, you see a minor surface water cut in our access road through the property. This stream comes with flooding, and goes away quickly, but with each passing storm, through the years, I’ve been watching this cut deepen, and if I don’t address it soon, the whole road could be compromised. Like any water issue, it starts as a drop, then seep, then torrent. Fix these little issues as they form, preventing massive soil erosion in time.
With all this heavy rain The Pacific Northwest is becoming more and more flood prone. Weather systems like The Pineapple Express, from Hawaii, are dumping atmospheric rivers, like the one pictured above. Where there was once a few inches over a few days, you now experience inches in hours, with 8-10″ in a weather event like this, and they are happening more and more frequently. This storm went for a week straight, and I was counting 2-3 inches a day at EEC Forest Stewardship. With more water on the way, I’m upping my gutter design to all metal, heavy gauge for torrential rain, with added strength to withstand the snow too. Our major flow routs are mapped, with good flow direction encouraged using catchment basins, sturdy culverts, and unimpeded swales, which guide water into the pond, or retain the excess in cisterns.
The 20,000 gallon tank above is designed to hold a winter’s worth of rain from the nearby green roof. Right now the roof catches into a much smaller green cistern, about 400 gallons at a time. Then we will use a portable pump to push the water from that tank, into the larger blue pillow. In Fall, 2018, the tank was filled from the well, and reached capacity easily in a few days without overtaxing our pump. Because we lucked out with a mild summer, I’ve saved the water for the upcoming summer of 2020. By then, we hope to have s pump system from the upright cistern to utilize all our rain water catchment, and with ran like we’ve just had this winter in 2020, the 20,000 gallons will be easy to retain.
Since the storms, we’ve continued to study the landscape as waters recede. And plans to put in a water bar across our access road will mitigate future weather erosion. The valley below is back to normal, with traffic still backing up, but not for hours with only one road in and out of town. However, landslides have left two major access routs to Duvall compromised, and shutdowns for emergency construction will continue into the Spring. Rains in the past few weeks have been lighter more Seattle like, gently misting across the landscape, catching on cedar branches and dampening fresh grass for the sheep to enjoy. I’d rather have too much water, than not enough.