Forest Roads and Their Effect on Water Quality

Forest Roads and Their Effect on Water Quality
Roads are often necessary to perform certain tasks in the forests. When roads
are made, they often pose the problem of erosion, and damage to nearby
water sources. The two articles I read on this topic were both from the
August 1999 issue of the Journal of Forestry. Both discuss the different
techniques and methods for trying to limit the amount of silt that contaminates
roads due to disturbance.
The first article, ?What We Know- and don?t know- about Water Quality at
Stream Crossings,? discusses the different methods used to cross streams, and
which method causes the most long term, and short term damage to water
supplies. Forest road crossings have become a concern, because they are
places where disturbance, and water run off cause silt to get into streams and
water sources. The three main methods discussed in detail in this article for
crossing a stream are: fording, using culverts, and either a temporary or
permanent bridge.

The most impactive method, according to this article was the practice of river
fording. This method causes inordinate amounts of downstream silt because
every time a vehicle fords a crossing, some contaminates are added to the
water, in addition to the silt on the stream bottom that is disturbed and
washed downstream.

In terms of impact, putting culverts in a stream causes about the same initial
impact, as creating a ford, but subsequent impact is less, because cars are no
longer forced to drive through the water. Culverts can cause problems too,
because of the potential for them to plug up, causing washout, and silt
deposits.

The third, and most preferable method, according to this article, is the
construction of bridges (either permanent, or temporary).
By doing this, virtually all contaminants remain free of stream water, because
the actual stream does not have to be disturbed.

The second article summarized, ?Forest Roads: Where Soil and Water Don?t
Mix? shared similar opinions on most points. This Article brought up
several additional and perhaps more idealistic points. According to this
article, most resource damage in an area is done in the first two years after a
road is constructed. During construction, this article points out that it is wise
to limit the number of stream crossings to a minimum.

When crossings are necessary, though, this article suggested the use of
sediment ponds, and not allowing water to build up it?s mass and momentum.
When momentum is built up, water will erode more of the earth, causing
more sediment build- up in streams.

Personally, I did not really realize that there was even an issue of too much
sediment in streams due to forest roads, and stream crossings. It was
amazing to learn of all the dangers to the environment caused by yet another
type of pollution. This problem might not cause the immediate and drasti
problems that other environmental issues might, but eventually, because of
our interactions with the forest and it?s waterways, we might alter the
ecosystems in ways that we can?t even fathom.

Forest Roads and Their Effect on Water Quality 9.6 of 10 on the basis of 3697 Review.