Notes from Windward: #69
Opalyn finds the elusive culvert!
"Over the river and through the woods to Grandmother’s house we go. . ." Sorry – that should read, "through the woods and over the creek to the mailbox we go".
the creek that bars the way to our mailbox
A few years ago an 18-inch diameter by 12-foot long culvert was placed to channel our perennial creek under the path to our mailbox. Then, when the county decided to improve Wahkiacus Heights Road, Walt climbed into our five-cubic-yard dump truck and got in line with the big dump trucks to bring excavated material into Mailbox Canyon. The additional soil would bury the culvert and provide a path to the mailbox.
Unfortunately, the little dump truck got carried away and instead of burying about 10’ of the culvert the entire culvert plus several feet at both ends disappeared under the new soil. The next winter was snowy and the following spring an exceptionally large spring runoff over ran the berm and quickly cut a new channel closer to the road.
One of my first intern projects last spring, was to try to find the downstream end of the culvert. The water seeping through the berm gave the general location of the culvert, so I worked on it for about 20-30 minutes most days until the water ran out and then set the project aside. Our soil has a lot of clay in it, and when its wet, it's easy digging; when it gets dry, it's time to find another project to work on.
Last month I returned to the canyon in search of the elusive culvert. Looking at the terrain and creek flow, I tried to focus my excavation work in the area that would most likely locate the culvert. After moving nearly a cubic yard of soil over the last six weeks, the downstream end of the culvert became exposed!
exposing the down-stream end of the culvert
Next will be to remove the soil inside the culvert then continue the excavation around it to provide space for creating a concrete and cinder block vault. Once the culvert is cleared then we can fill in the current creek area (on the right of the first photo).
digging the dirt out of the culvert
In a few weeks, after the surface water dries up, we'll be able to work on the upstream side of the culvert and create an entrance lock that will keep the culvert free, but also allow us to close it off when we want to divert the creek water into the hydroelectric generator we want to install down at the new entrance. With more than a hundred foot of elevation change between the culvert and our new entrance, we will be able to generate electricity during the overcast winter months when we can't rely on solar for our energy.
That was back when the county road department decided to straighten and partially pave the road that runs along Windward's western boundary. They brought in a huge track-hoe and a couple of massive 10-cubic-yard dump trucks to haul away the dirt they excavated in the process of straightening out the road.
While that work was getting underway, I was able to track down some 24-inch diameter sections of concrete culvert. The road crew was kind enough to use their big track-hoe to set the culvert sections into the creek bed, and then piled a few hundred cubic-yards of dirt on top of that to create Windward's new entrance. It was a win/win deal because they saved money by not having to haul dirt very far, and we got the base for our new entrance put in place.
The place where I found the 24" culverts also had a twelve-foot length of 18-inch-diameter concrete culvert. When their work had progress up to where our mail box is, the track-hoe operator was kind enough to set the 18" culvert in the stream bed at the point where we cross the stream to get to our mailbox. With the culvert in place, I cranked up our more modest 5-cubic-yard dump truck and spent a couple of days waiting my turn in line with the big trucks so that I could haul away more of the dirt the track-hoe was excavating. I dumped dozens of loads of the fill dirt around Windward in places where we want to eventually create terraces such as in front of the dining hall.
When the dust cleared, I was chagrined to note that the culvert at the mailbox had gotten covered up. My intent was to get the culvert cleared before the next spring run-off, but other things intervened and the spring melt overran the berm. The loosely packed dirt was quickly eroded away, leaving what we affectionately call "Mailbox Canyon." Since then we've been dumping rocks into the gully that was eroded through the berm, to provide stability for the dirt we'll eventually fill the gully with once the culvert is clear and able to handle the seasonal run-off.
our "twin" creeks
Notes From Windward - Index - Vol. 69