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McAtee Construction Company Page 4 <br /> Bank Armoring Plan <br /> the WGS 84 we use since in the 2013 flood event the water level <br /> never exceeded 4 feet . <br /> There are general items that will be common to both armoring <br /> area. In general, all armoring material will be recycled <br /> concrete and asphalt fragments that meet the definition of Inert <br /> Materials, there will be no exposed rebar in the concrete and it <br /> will be sized to D50 or greater. To be classified as D50 the <br /> concrete will be sized 9 to 15 inches averaging 12 inches . Fines <br /> will be mixed in to fill voids . This size material will have a <br /> Safety Factor of 1 . 26. See Bank Armoring Calculation page <br /> following this text . The toe of the armoring will be a minimum <br /> of 3 feet below the existing ground level as described below. <br /> McAtee will keep enough material stored on the mine to complete <br /> armoring needed on an area as it is mined and ready for armoring. <br /> The attached Figure G-1 shows the cross sections of the areas <br /> discussed below and details of the armoring will be placed to <br /> protect areas within 100 feet of the river or west ditch bank. <br /> Map Exhibit F - Reclamation Plan Map has been revised to show the <br /> location of the areas to be armored in the mine . <br /> Lake Robert Inlet <br /> This area covers the 90 feet wide by 45 feet long area where the <br /> 2013 flood breached the south lake bank into the Lake Robert <br /> area. To permanently reconstruct the damaged area on the south <br /> line of the permit area and finish reclamation in that area, an <br /> inlet spillway will be placed in the area originally breached. <br /> The spillway elevation will match the outlet elevation so if it <br /> ever flood again the lake area will fill during an event that is <br /> below the 100 year elevation. The plan is to use 5h to lv slope <br /> from the existing surface to the top of the spill way on both <br /> sides to make it easer to cross . The top will be 2 foot lower <br /> then the ground surface . The armoring of the spill way will be <br /> placed 3 feet below the existing flow channel and the north and <br /> south slopes will be graded 3h to lv. This will leave a 15 foot <br /> wide crest so the power lines can be accessed. If the FEMA <br /> elevations are correct then the crest of the spillway will be 9 <br /> feet blow the flood crest allowing the lake area to become full <br /> prior to flooding occurring. <br /> The size of the spill way was determined by what it would take to <br /> repair the damage done during the last flood. Now that the ditch <br /> company has fixed their return flow spillway, the return flows <br /> from this area are back to normal . No water has entered the mine <br /> from the overflow channel since 2016. In this area the river <br /> channel is more then 400 feet from the mined area and there is no <br /> direct wet connections between the river and the permit area on <br /> the south end. Estimated volume of inert fill (concrete and <br /> Revised - July 19, 2022 <br />