Printed in the Mendocino County Observer and aired on KZYX&Z Community News.
After one of our winter storms is a good time to take a look the water under your bridge (or in your inside ditch or flowing out of your culvert) and see what color it is. Is it brown or is it clear? The color will give you an indication of how much erosion is occurring.
Brown water is an indication of erosion. What causes the brown color is, of course, sediment that is suspended in the water. An interesting experiment is to take a glass jar and fill it with brown water from a watercourse. Put it on a shelf and let it settle for a few days. You'll be able to clearly see the sediment at the bottom of the jar.
While a certain amount of erosion is natural, poor drainage from roads is a frequent cause of excessive erosion. If your water is deep brown or runs brown for long periods of time, consider taking steps to reduce erosion from your roads.
First, maintain existing roads. Fix small drainage problems as soon as you can, before they become big problems.
Next, get the advice of a specialist like a professional forester to figure out where problems are likely to occur in heavy rains. Upgrade your roads to be able to handle storm events.
Finally, put a cap on your road density. Don't put in new roads unless absolutely necessary. And if you have to do so, see if there is an equal length of road somewhere else that you can abandon. (It's a good idea to get the advice of a professional on how to properly decommission a road.) Other factors being equal, the fewer the number of miles of road, the less erosion there will be.
And if the water under your bridge runs clear during and after storms? Take a moment to enjoy the knowledge that your forest soil is staying in the forest.
Clare Nunamaker is a Registered Professional Forester and member of NorCal SAF and the Forest Guild. forestry@nunamaker.com
707-485-8788
