Advance notice of 2 weeks needs to be submitted to the Forestry Administrator prior to starting work. Before the crushed gravel is applied, the trail bed must be built up with adjacent shoulder materials, and graded to allow for proper runoff without road degradation. This is to cover exposed rocks, fill in washouts and build up low areas where water gets trapped and pools. Drainage wings may need to be installed. Generally high side to low side of the trail will have slopes of 2-3%. Before the crushed aggregate is applied, a representative of Marinette County will inspect the trail bed buildup, culvert installation and authorize continuation of the project when satisfactory. The culverts need to be a minimum of 15” in diameter and can be either double wall plastic or steel construction. Length of culverts needed may vary by individual location, but all will be a minimum of 16’ in length. Actual length of culverts need to allow for 1 foot of stick out beyond the sloped edges of the trail base on both sides. Riprap around the culvert mouth is not required. Approximately ½ of the trail length will have 4” of ¾” crushed aggregate put down and ½ of the trail length will have 6" of ¾” crushed aggregate put down. The width of the trail is approximately 12’ on average. The sections that will require 4” or 6” of crushed material are designated on the map. After the crushed aggregate is spread, it must be compacted and grade maintained to allow for proper drainage. The entire stretch of trail must be graveled to the specifications on the map of 4” or 6” depth. It is estimated that the project will take approximately 3,636 cubic yards of 3/4” crushed aggregate to be brought onsite.
