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3. Smith Letter to Public Works 5-5-15May 5, 2015 Tim Kieffer Public Works Director Scandia, Minnesota Tim, Thank you for meeting with me (and a few others) at the landing after the last Council meeting. It was helpful to know what your motivation was in choosing to regrade the landing at this point in time. I thought it would be useful to summarize our conversation - if nothing more than for historical documentation of work done to the road. Following is my understanding of your thinking based on our conversation: Past maintenance has resulted in a flat road (no slope) with little ability to direct storm water. This resulted in ruts in the road and runoff into Gilbertson Creek and the river during very heavy rains. The county engineers had recommended a 4% inslope to allow for adequate storm water drainage. You felt that regrading the road to provide the 4% inslope to the north, would help as an interim measure. Rather than adding gravel, you hoped to move dirt from the north to the south, thereby creating this inslope. This is a temporary measure and without any storm water system in place (like a rock ditch,) any new heavy rains will likely result in one long rut/channel on the north side of the road. You believe that this parallel rut will be easier to repair and maintain and may be less disruptive to those using the road. You also hope that the slope will direct water away from Gilbertson Creek and that the rock piles on the north side of the road will help slow the water so that when it reaches the landing it will sheet over a wide surface and dissipate. You anticipate that some adjustments/reshaping may be necessary after a few rain events and hope that we are lucky and will get some light rains in the next few weeks. This will give you the opportunity to make the minor adjustments and compact again before any heavy rains. (I see that you have already started this process and that there was some minor regrading done this morning.) Once the minor adjustments are done, you hope that the road will perform well throughout the summer and require little or no maintenance. You also acknowledged that prior to regrading, "the road was in pretty good shape and required only minor repairs," and that you were unaware of the Watershed request to do minimal work on the road while options were being considered. As a follow-up to our meeting, I spoke to the gravel road engineer/consultant who is assisting us with work for the Watershed LHL working group. Ken Skorseth recommended this engineer who specializes in gravel roads. I discussed the particulars of the LHL situation post -regrading and the following are suggestions that came out of those conversations: 1. Compact the secondary shoulders where possible. These are the dirt piles alongside the road, particularly west of the tracks, that were created in the grading. I can see that you have already done this east of the tracks on the south side of the road. Currently there are loose piles of dirt and rocks on the upper part of 205th. See attached photo. 2. Remove as many of the newly -exposed rocks in the road surface before any re -compaction. I see that some of this has been done, and several of us have also been rock -picking in an effort to help. For a gravel road to perform well, normal grading specifications call for a surface tolerance of 1/2" in 10 feet. This means that you don't want to see more than %" variation in surface over a 10 foot section. If the surface is left open to traffic after grading, the amount of deviation will increase due to wear in the surface of the gravel surfacing. I understand that without adding gravel this was a difficult, if not impossible, specification to meet. However, the more rocks that can be removed prior to any re -compaction, the better. 3. After the first few rains and when there is still moisture in the dirt, make minimal repairs to smooth and re -compact the surface as needed. Some reshaping may be required, but the less disruption to this new surface and the more compaction, the better. (Again, this process seems to have started.) 4. A roller is the best tool for compaction of the road surface. It has a higher down pressure, but if one is not available, the grader tire method you used will work temporarily. 5. If water runs too quickly down the north channel/rut that you anticipate forming as a result of the new inslope, and is not slowed sufficiently by the pile of rocks on the north side, consider installing water bumps. I realize that this may be more maintenance than you want to do as an interim measure and that you feel these are difficult to maintain in the winter, but they will work well to slow water and channel it more effectively if it becomes a problem (they will also slow down the occasional speeding teenager. (D) 6. Work to make the landing surface as smooth as possible for the most effective sheeting. Currently the surface is loose and somewhat choppy. It would also be helpful to grade as much away from the bank when reshaping and compacting. I hope that these suggestions are taken in the respectful way they are intended, and may be of some use. Thank you for your time and all of your efforts over the last 6 months in working to develop the best possible plan for this unique and historic site. I also very much appreciate your agreement to keep lines of communication open and advise the Watershed and its working group of any future plans to make changes to the road. I wish you the best of luck in your new Golden Valley venture! Sincerely, u '.iiniifiO1iMI Friends of Log House Landing