1710 W MARINE VIEW DR 2024-01-03

. Grade the approach to the inlet uniformly. . Drill weep holes into the side of the inlet. . Protect weep holes with screen wire and washed aggregate. . Seal weep holes when removing structure and stabilizing area. . Build a temporary dike, if necessary, to the down slope side of the structure to prevent bypass flow. Block and Gravel Filter A block and gravel filter is a barrier formed around the inlet with standard concrete blocks and gravel. See Figure 11-3.17: Block and Gravel Filter. Design and installation specifications for block gravel fil- ters include: . Provide a height of 1 to 2 feet above the inlet. . Recess the first row of blocks 2-inches into the ground for stability. . Support subsequent courses by placing a pressure treated wood 2x4 through the block open- ing. . Do not use mortar. . Lay some blocks in the bottom row on their side to allow for dewatering the pool. . Place hardware cloth or comparable wire mesh with 1/2-inch openings over all block openings. . Place gravel to just below the top of blocks on slopes of 2H :1 V or flatter. . An alternative design is a gravel berm surrounding the inlet, as follows: • Provide a slope of 3H :1 V on the upstream side of the berm. • Provide a slope of 2H:1 V on the downstream side of the berm. • Provide a 1-foot wide level stone area between the gravel berm and the inlet. • Use stones 3 inches in diameter or larger on the upstream slope of the berm. • Use gravel'/z- to'/4-inch at a minimum thickness of 1-foot on the downstream slope of the berm. 2019 Stormwater Management Manual for Western Washington Volume 11 - Chapter 3 - Page 358