Laserfiche WebLink
Task 3 <br />Rock Check Dam Construction: <br />Rock Check Dams are required in three areas; along the access road, on the portal bench and <br />the o utslope of the fil l. See drawing for locations. The rock will be collected by the <br />CONTRACTOR at a location specked by the PROJECT MANAGER. Rock check dams shall be <br />installed as follows: <br />Access Road- Small erosion features extend down the slope approximately 200 feet. <br />Install a rock check dam every 20 feet as directed by the Project Manager. Rock check <br />dams shall consist of - 1111 . 24" diameter rock us ing on site material. Rock check dam <br />dimensions will be 3' long by 3 'wide? - 5Y – Z r— d — eeP at the base of the dam an will be key ed <br />in to a depth of 2' elow ground surface. acement will be such that voids will be <br />eliminated to the extent possible with rock contacting rock and smaller rock used to fill <br />any voids. <br />Portal Bench- One large a ature extends down the graded portal slope for a <br />distance of approximate0 feet, Rock check dams will be installed every 10 feet as <br />directed by the Project Manager. he Rock Check Dams will be constructed according to <br />the attached Drawing 2. Drainage Course Rock- Rock Outcroo to Slooe and Check Dam <br />- <br />X-Section & Plan Rock check dam rip rap, available on -site will consist of an evenly <br />distributed combination of 60 °� minimum 4' diameter rock rip rap, 20% 2' to 3' fo <br />diamet O k 12" to 18" rock Th 4' dia meter rock will be keved into the <br />rock. The 2' to 3' diameter rock will then be placed over the smaller rock to fulfill the 30° <br />minimum riprap depth requirement. The check dam will be constructed in a V -shape w ith <br />the middle of the V situated ' - stream in elevation. Rip rap will extend <br />a minim up the side slopes. Side slopes to the constructed channel will be at a <br />maximum 21-11V slope. Positive drainage will be maintained from the bench cut into the <br />drainage channel. See Drawing 2 for more detail. <br />Fill Outslope- Small erosion features extend down the slope approximately 100 feet. <br />Ins a roc c check dam every 20 feet as directed by the Project Manager. Rock check <br />dams shall consist of 18" to 24 using on si a matena . chec ams will be 3' long <br />by 3' wide by 2' deep at the base of the dam and be keyed in to a depth of 2' below <br />ground surface. Placement will be such that voids will be eliminated to the extent <br />possible with rock contacting rock and smaller rock used to fill any voids. <br />Measurement and Payment <br />Measurement for payment will be accomplished by counting the number and type of rock check <br />dams constructed and accepted by PROJECT MANAGER. Payment will be made at the unit <br />prices established in the Bid Schedule for Items 3a, Road / Fill Outslope Check Dams, and 3b, <br />Portal Bench Check Dams. The unit prices established in Items 3a and 3b of the Bid Schedule <br />will be: considered full compensation for all costs and expenses, necessary and incidental, to <br />construct the check dams as described, including excavating, hauling and placing the rip rap <br />material. <br />6 <br />