6.4. SR 04-20-1998 - Laserfiche WebLink

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be from this area to restore it to its original navigable depth and act as a basin for future sedimentation. Area N - Area "N" is the portion of the Elk River immediately upstream of Lake Orono. Creating a sedimentation basin in this area to limit the amount of sediment finding its way to Area "L" was considered. Because it is difficult to go deep enough and/or wide enough in this area to significantly slow the river water, Area "L" was ruled out as a location for a sedimentation basin. Material in Area "N" that will quickly deposit in the lake after sediment is removed from Area "L" will be excavated as part of the project. Removal of this sediment also allows for better access up river. A combined total of 90,000 cubic yards is proposed to be removed from Areas "L" and "N" with the bulk of material coming from Area Area K - This area is basically a sand bar jetting out from Boy Scout Island that is a safety hazard for boating. This area is proposed to be made a minimum of 3 feet deep by the removal of 3,500 cubic yards of material. Area C - For boating safety, like is the case with Area "K", 13,500 cubic yards of material is proposed to be removed, making this area a minimum of 3 feet deep. Erosion on adjacent Cemetery Point is proposed to be corrected as part of the project. Area I - A small access channel 3 feet deep and 48 feet wide is proposed in the extreme northwest comer of this area. Sediment from an adjacent storm sewer outlet will also be taken. Approximately 2,000 cubic yards of material is proposed to be removed from Area 'T'. Area J - This is an optional area. Creating a minimum 3 foot depth in areas of the lake that get a lot of watercraft traffic was one of the rationales used to determining where sediment should be removed. Except for the portions of this area that are in close proximity to islands, the area has little for sediment deposits that are shallower than 3 feet. However, there are some high spots in this areas. Removal of the sediment from this area is difficult due to the need to cross the river channel running through the lake. Leveling the high spots in this area and leaving the material in the lake has been proposed as an alternative (approximately 6,000 cubic yards of grading). Disposal Sites Map # 3 shows the general location of the disposal sites. Areas adjacent to the lake were selected as disposal sites to avoid the cost of reloading the sediment into on-road trucks and tracking the material away. Detailed maps of the disposal sites were provided in the lake improvement feasibility study.