Sunday, March 25, 2018

Spring Thaw Update #1

We went out to scope trails in Van Peenen this morning (Sunday, March 25th 2018) when temps were around 26 degrees. As you can see, things are still on the fritz when it comes to Spring Thaw conditions.

IPT has a lot of ice cover (to be expected) and it wouldn't be surprising if it were closer to the middle of April until things shape up (considering our current weather pattern.)

Temps are still going down into the freezing temps at night and warming up during the day- this means frost is still coming out of the ground in many areas.

Not too much damage from bike and foot traffic, but you can tell there have been users out in less than ideal conditions. A lot of pock-marks from deer hooves. You'll have a bumpy ride no matter what.

We have an album up on Facebook for Van Peenen (so far.)

We are not going to waste our time with daily checks at this point. With thick ice in spots, it's not going to change an awful lot in a single day.

One of our trail checkers reported that Dunnings was shaping up on a couple trails, but the majority still had some ice and/or were soft in above freezing temps.

Long story short- unless you ride our trails in the morning while temps are still below 34 degrees, please respect them and stay off until they have firmed up.

Thursday, March 8, 2018

Freeze/Thaw Cycle

Trail ruts caused by riding partially thawed trails.
The transition from winter to spring is here and local trails will be experiencing freeze-thaw cycles. This means trail conditions will be unsuitable for riding until the ground freezes solid and daytime temperatures stay well below freezing.

What's the big deal with freeze-thaw cycles?
Dirt trails are extremely vulnerable to rut damage during the transition to and from winter because colder temps prevent the soil from drying. When soil freezes the growth of ice crystals push soil particles apart leaving large gaps that can fill with water when the ice melts. In a thawed state this dirt is much like a sponge and will absorb large amounts of water. It is also hypersensitive to disturbance by foot/bike traffic and flowing water and will form ruts with little effort. Direct sunlight and above freezing daytime temperatures can thaw the top layer of frozen dirt and create an easily rutted, greasy, muddy mess on the surface. Overnight, lower temperatures refreeze the top surface of the trails, ruts included, and the process repeats when conditions allow (hence the name freeze-thaw cycle).

Why are ruts bad for trails?
When ruts develop along a trail they channel water, causing erosion of the trail surface, and slow the drying process. Rain is highly erosive to trails when the ground is frozen and ruts greatly increase the chances of erosion by flowing water. When the soil is frozen, water can't soak in like normal and flows along the top in large quantities. Ruts on a trail can intercept these flows and divert them along the length of a trail. As the water flows down the trail and picks up speed it also picks up soil particles and washes them away from the trail. This can leave behind deep ruts tens or hundreds of feet long in extreme circumstances. Come springtime, ruts can also hold pools of water on the trail surface and prevent it from drying as quickly. If these puddles are disturbed by bike tires they can quickly turn into large mud pits. Fixing these areas eats up trail volunteer time that could be better spent on other projects. Wet areas like this also prolong trail closures.

Tips for riding during the winter/spring months where temps fluctuate between freezing/above-
Pay attention to the trail status
Don't ride frozen trails when the temperature is above freezing.
Ride frozen trails early in the morning before they have a chance to warm.
Don't ride if the temps are hovering around freezing and it is sunny. Wait until temps are below 25F and even then there may be thawed areas.
If after following all the above guidelines and the trails are still too soft, turn around and come back another time. A single rider can damage many thousands of feet of trail under these conditions.

Please respect the trails during the transition months in the winter/spring so everyone can maximize their enjoyment come springtime!