More Hydrology: Draper Bikeway

We proclaim in our Radix Fidem covenant an affinity for the natural world. We seek to understand God’s moral character by understanding how Creation works. That includes some grasp of the mechanics. It’s not as if everyone should become an herbalist, but we sure need a few folks like that. We also need folks who can deal with animals, weather, geology, soils, etc. That includes what is generally referred to as hydrology: the earth science of water and flows. Earth Sciences in general are something that we tend to emphasize.

I am by no means an engineer or scientist, but I have learned an awful lot through my own inner drive and talents for understanding certain aspects of nature, to include a lot practical experience in hydrology. I learned most from mistakes, my own and those who were paid to know better. Seems to me that a major element of failure in construction engineering is not paying attention to hydrology. Having the leisure to play with fixing the mistakes of others has taught me an awful lot. Our first image above shows water collecting in a driveway to an picnic area, because it has no place to go. It’s not too bad simply because there is plenty of gravel embedded in the soil. Even when totally saturated, it gives only so far and then remains stable. You can drive through that standing water and not get stuck.

Part of the game is that there isn’t a lot of water flowing into that puddle from somewhere else. It’s just a couple hundred square feet (19m²) or so of watershed. So while I’m not happy about this image on the right where the bike path is cut almost a yard/meter deep in the soil, it’s a relative hilltop. There will be no great amounts of water flowing into this spot. It’s not good engineering, but it’s not a disaster, either.

Consider the soil in these parts. That red clay tends to get saturated quickly in rain showers, and run-off is a high percentage after just a few minutes of hard rain. However, leave that water against the soil for long periods, and capillary action will see a very deep lateral penetration. So if the water pools up, or simply slows down across a nearly flat grade, you’ll see a fairly deep saturation of this red clay that spreads over wide areas. The image on the left here shows just such an area.

I swear there weren’t any actual trail users on the team of folks who engineered this bike path. They would have known that this section of lake shore road (laid way back shortly after the lake was built in 1962) has always been a mucky clay mess. It’s near the bottom of a funnel capturing an acre or more of watershed. This image of an aerial view of that same area shows a lavender line parallel to the currently planned bike path. It represents the portion that is a funnel for the entire area outlined in yellow. All that water runs across there, and the road is an artificially raised area that slows the flow dramatically. This thing stays mucky for weeks after the last rainfall. It really should be elevated, graveled, and a couple of culverts run underneath. Even better would be a small catch basin on the high side of the trail that allows the flow to proceed under the path following heavier rains. We do have flash flooding around here.

A couple of other interesting notes. Stanley Draper Lake is also known as East Elm Creek Reservoir; it captures East Elm Creek and a few tributaries, plus all run-off from the surrounding terrain. I previously noted on this blog there were plans to extend Draper Lake to include West Elm Creek. I noted that a short section of dam west and north of the main dam would likely have water on both sides if they ever did build that extension. But apparently the West Elm Creek project has been tabled indefinitely. In this image we see the bike path dropping below the short dam, in what would be underwater in any proposed expansion of the lake.

What I previously called “early crop blackberries” is actually dewberries. It’s closest relative is the raspberry, and these are properly called “black raspberries.” They taste very close to blackberries, though. These aren’t anywhere near ripe. They produce generally far more berries that our local wild blackberries, and the season runs late May through mid-June at least. These things are close to the ground and grow like thin vines, whereas blackberries grow in very thick branched and very thorny stems that stand upright. They come out just as the dewberries begin fading. In ideal soil, the two overlap a week or two, growing sometimes side by side.

It’s all part of knowing our Father’s Creation, in turn part of knowing God.

This entry was posted in Uncategorized and tagged , , , . Bookmark the permalink.