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culvert would be the most expensive option at the HR-6 outfall <br />point, the quarry operator would not have to construct the <br />roadside swales to handle diverted runoff, and the operator would <br />have a decreased liability for runoff and sedimentation damage at <br />the 54/30-inch culvert resulting from the diversion of flow from <br />its historic path. Stabilization of the of the natural swale <br />downstream of HR-6 should be the responsibility of the Cedar <br />Heights property owners, as well as the construction of a <br />culvert(s) under Cedar Heights Drive. It is recommended that a <br />100-year culvert be constructed under Cedar Heights Drive at the <br />location of proposed culvert "A" so as to prevent an overflow at <br />this location, however the size of this culvert would be up to <br />the Cedar Heights propert}• owners. Stabilization of the natural ~~~k <br />Swale can be achieved by the cr.~nstruction of timber checks spaced ~ ( <br />periodically along the length of the Swale. The size of the 100- ~f ~ ~ <br />year metal pipe culvert under the quarry access road is estimated <br />at between 36- and 42-inches assuming a headwater to depth ratio <br />of at least 1.5. <br />Option 7: This option is not feasible based upon the review of <br />the topography of the area. Additionally, this option is a plan <br />which would result in the diversion of flow from historic path <br />which is not recommended. <br />Conclusions <br />As a result of our review of the information relevant to this <br />project, the following conclusions have been reached: <br />(1) The flow originating from the HR-6 basin is considered to be <br />"historic" in nature and should remain in the natural Swale <br />through the Cedar Heights property. <br />(2) Options which consider the diversion of flows from the <br />historic path should be avoided because of the potential for <br />damages resulting from drainage and erosion along the access <br />road. <br />l3) Stabilization of the natural Swale should be considered by <br />the Cedar Heights property owners. The installation of <br />stabilization structures should be phased as the natural Swale is <br />impacted over time by the historic runoff from the HR-6 basin. <br />(4) The operator of the quarry should be responsible for IS~~;~ji~~1R- <br />removing the existing loose sediments upstream of the access ~~ <br />road and stabilizing these same areas so that sediment ~Ww'bW <br />available for transport to the natural Swale is minimize3. The <br />stabilization of disturbed areas along the quarry access road <br />including the safety berm along the east side of the access road <br />should be the responsibility of the quarry operator. <br /> <br />