Laserfiche WebLink
To increase infiltration, improve flow attenuation and reduce structural <br />problems associated with subgrade erosion on slopes, impermeable <br />check dams may be placed on the subgrade and below the pavement <br />surface (See Fi_ure. 5.3.6). Check dams should have an overflow drain <br />invert placed at the maximum ponding depth. The distance between <br />berms will vary depending on slope, flow control goals and cost. <br />LONGITUDINAL SLOPE <br />PERMEABLE <br />NON —WOVEN <br />GEOTEXTILE <br />STORAGE <br />WITHIN CELL <br />OVERFLOW PIPE, INVERT TYP. SET <br />AT THE CREST ELEVATION OF THE <br />DOWNSTREAM CHECK DAM <br />CHECK DAM, <br />IMPERMEABLE <br />MATERIAL <br />Modified from Seattle <br />ROW Manual <br />Figure 6-25 <br />Figure 5.3.6 — Example of a check dam along a sloped section of permeable pavement <br />Volume V — Runoff Treatment BMPs — December 2014 <br />5-23 <br />