Blue Clay wet forever?
(updated: Dec 29, 2009)
So with the recent heavy rains that seem to occur with weekly frequency, the local trails have become a sloppy muddy mess. And it's not just Blue Clay...UNCW was also underwater on Sunday as John unexpectedly discovered. A lot of that is due to the university expansion over the past couple of years.
Not only has there been more rain, but the timing is bad as well. The colder temps mean less evaporation, and the trees and vegetation are dormant and are not soaking up the water.
But let's look at the data, and see if it tells us anything. Below I have annual rainfall data for Wilmington.
This is monthly data since 2004. The most striking thing is the increased rainfall since October 2009 versus the prior years. In December we have twice the amount of previous years. That alone explains a lot. I'm not as concerned with summer rainfall as it tends to run off, get absorbed by growing vegetation, or evaporate.
Continued cold wet weather means that the water table will remain high and we will not likely see Blue Clay dry out until spring, if then.
This is a chart of annual rainfall for Wilmington since 1990. In the early 1990s the original trails were built at Blue Clay. We started reclaiming the trails in 2005, a relatively wetter year. 2007 the trails were very dry if I recall correctly, and the data confirms it.
Last is a chart of the complete data going back to 1871. Notice the long term upward trend since 1900. One of the predictions from global warming theory is that we should have warmer and wetter weather here. Not saying that this is confirmation of anything, just an observation. Power-law statistics requires observations over a time period commensurate with earth-climate time periods, which means hundreds of years. This is because of the strong dependence of extremes on the length of observation for a 1/f^-3 type power law. The problem with this is once you have enough data to know for sure, it's too late to do a damn thing about it.
You can download the spreadsheet with the data here:
So what is the solution for our piece of the swamp we live in? What we have is really no different than trails north of us. They are not often rideable in winter or spring. But we would like to take advantage of our favorable climate. And we do have a solution that CF SORBA is already working on: rock armoring the trail. It will take some time...there is a lot of regulation and approvals involved. But in the end we will have a trail that can be ridden all the time.
Couple of night riding pics from a few weeks ago, the last decent ride I got in at BC.
Google Earth (.kml) files and GPS eXchange (.gpx) files.
TRAIL GPS COORDS (4)
1. Erik said...
Thanks for this information - very interesting. One has to wonder - the rain seems to come intermittently just when BC could possibly open up. Pretty frustrating.
Dec 30, 2009 @ 7:09 AM
2. dude said...
Looks like Ed's dog has built in LEDs-
Dec 30, 2009 @ 9:59 AM
3. Rock Head said...
Hold fast to the wet trail rule; you don't want the trail to end up like Greenville, which can give you tennis elbow from the beating from the roots. The price we have to pay for living along a tidal forest (Course the shoulders can stay sore from hours of surfing when there are weeks of waves; its all good).
Jan 1, 2010 @ 5:32 PM
4. robert legg said...
Nice to see the graphs and stuff showing history.I think historically what the locals have always called this trail is "THE MUD TRAIL". The need is to create a plan and to carry this knowledge forward. Post work days and hopefully people will come out. Any thought about replacing the elevated portions in the first section? I don't think hardening the trials will work in those areas. It is a good idea though for some of the spots on the trail.
Jan 10, 2010 @ 10:27 AM
5. Barry said...
The basic question is what to do about the flat areas of the trail...first of all, look for elevation to aviod any flat areas! If that isn't possible and you have to have a flat section of trail there are two options: 1) build a (ladder) bridge over the wet section, or 2) rock armor the section of trail...building a raised tread that will shead water off the trail. The first option is costly, requires maintainence, and takes time to build...but doesn't require any permiting. The second option is less costly, requires little to no maintainence,and takes time to build...but does require a permit that will take more time.
Either way...the county will have to approve what is done to the trail because it is their trail!
Jan 23, 2010 @ 12:26 PM
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