1300 W MARINE VIEW DR 2018-01-02 MF Import

Page 25 of 46 The time period may be adjusted by a local jurisdiction, if the jurisdiction can show that local precipitation data justify a different standard. c. Soils shall be stabilized at the end of the shift before a holiday or weekend if needed based on the weather forecast. d. Soil stockpiles shall be stabilized from erosion, protected with sediment trapping measures, :uid where possible, be located away from storm drain inlets, waterways, and drainage channels. 6. Protect Slopes a. Design and conctruct cut and fill slopes in a manner that will minimize erosion. Applicable practices include, but aze not limited to, reducing continuous ]ength of slope with tcrracing and diversions, reducing slope steepness, and roughening slope surfaces (e.g., track walking). b. Off-site stormwater (run-on) or groundwater shall be diverted away from slopes and disturbed areas widi interceptor dikes, pipes, and/or swales. Off-site stormwater should be managed separately from stormwater generated on the site. c. At the top of slopes, collect drainage in pipe slope drains or protected channels to preventeros�on. i. West of thc Cascade Mountains Crest Temporary pipe slope drains shall handle the peak 10-minute velociry of flow' from a Type lA, 10-year, 24-hour frequency storm for the dcvcloped condition. Altematively, the 10-yeaz, 1- hour flow rate predicted by an approved continuous runoff model, increased by a factor of 1.6, may be used. The hydrologic analysis shall use the existing land cover condition for predicting Flow rates from tributary areas outside the projcct limits. For tributary areas on the project site, the analysis shall use the temporary or permanent project land cover condition, whichever will produce the highest flow rates. If using the WWHM to predict flows, bare soil azeas should be modcled as "landscaped area." ii. East of the Cascade Mountains Crest: Temporary pipe slope drains shall handlc the expected peak flow velocity from a 6-month, 3-hour storm for the developed condition, rcferred to as the short duration storm. d. Excavated material shall be placed on the �phill side of trenches, consistent with safety and space considerations. e. Check dams shall be placcd at regular intervals within constructed channels that arc cut d��vn a slope. 7. Protect Drain Inlets a. All storm cirain inlets made operable during construction shall be prorected so that stom»vater runoff does not enter the conveyance system without first being filtered or treated to remove sediment.