Laserfiche WebLink
<br /> <br />a3. The application contains an SCS report which includes reclamation <br />recommendations and a proposed seeding mix. There is, however, no <br />indication that these SCS recommendations will be followed. Please ~~ <br />commit to following the SCS recommendations in their entirety, or <br />indicate how your reclamation/revegetati on plan will deviate from <br />what the SCS has proposed. <br />Water Information (Exhibit G) <br />9. The application states that the mining area is within the 100-year <br />flood plain. Please provide mapping delineating the 100-year flood 1.1 <br />plain limits. What is the discharge associated with this event? <br />10. You propose to build up and armor an existing dike on the south <br />edge of Cell A, leaving a depressed area about 100 feet in length <br />to allow controlled inflow of flood waters into the pit. Please <br />provide the following additional information: <br />a. Waste concrete is proposed as the armor, What is the planned <br />thickness of the concrete armor layer? Will the concrete be <br />poured in place or transported to the site as blocks? How does J'. <br />the concrete rubble compare to riprap in terms of durability? <br />b. What is the depth of cover to be placed over the concrete? ,~ <br />c. What is the slope angle of the riverside face of the berm? ~~• <br />d. Although the top of the berm will be revegetated and should be <br />adequate to control erosion of the spillway during flood <br />conditions, the Division recommends the sides of the spillway <br />also be reinforced with buried concrete. This is recommended <br />to contain flood flows within the spillway and prevent sideward <br />erosion of the unprotected berm. <br />e. At approximately what frequency can the discharge of stormwater ~ <br />into the pit be expected? (5 years? 50 years?) <br />11. You propose to leave a similar depressed area in the dike to <br />control flow from Cell A to Cell B. What is the length of this <br />depression? What is the size of the proposed culvert between <br />the cells? <br />12. Outflows during flood conditions are proposed to overtop the <br />berm, spread out and find their way to the river. The Division <br />recommends an outlet spillway, similar to those provided as an <br />inlet to Cell A and between the two cells, be constructed as <br />well. The preferred location would be closest to the river in <br />the northwest corner of Cell B. If not included, what length <br />of berm would be overtopped and what assurance can be provided <br />that no off-site damages will occur to the adjacent property? <br />