25 104TH ST SE 2018-03-29 - Laserfiche WebLink

Proposed Site Information: 1. How will your project change the existing conditions? There will be a new house constructed with a walkway and driveway from the walkway along 104th to the new house 2. Please provide the following quantities of proposed hard surfaces in square feet: Proposed Roof Area: 2198 Sf Proposed Other Hard Surfaces(pavement,gravel,etc.): 452 Sf 3. How will you manage rooftop runoff after the project is completed? Downspouts will discharge to splashblocks.The ones with less than 50' of flow path will travel in a grasslined swale to the southeast corner of the property so no water will flow to the neighboring property to the east.All water will flow to the right of way along 104th 4. How will you manage stormwater runoff from hard surfaces(driveways, paved pathways, patios,etc.)? Evaluate each type of hard surface separately. Drivway will flow to the street or be dispersed in the lawn,the walkway will be dispersed into the lawn. No other hard surfaces are proposed. Plan for Permanent On-Site Stormwater Management: You are required to "infiltrate, retain, and disperse stormwater" on your site to the maximum extent you can without causing erosion or flooding.The goal is to get stormwater runoff in contact with vegetated surfaces as much as possible before discharging to downstream conveyance.systems. See Volume III, Chapter 12 of the 2010 Storm water Management Manual for stormwater facility requirements: https://everettwa.gov/DocumentCenter/Home/View/1214 1. Determine which options you must use for managing stormwater from rooftops via downspout disconnect by considering the following Best Management Practices (BMPs) in order: • BMP 12.30 On-site Infiltration Areas • BMP 12.40 Raingardens • BMP 12.50 Downspout Dispersion Notes: a. If location criteria can be met, but sizing criteria cannot,you must implement the BMPs to the maximum extent you can without causing erosion or flooding. Pre-sized facilities have been designed to meet 100% mitigation. Facilities may be able to be installed to achieve some stormwater mitigation. b. Other innovative downspout control BMPs such as rain barrels,ornamental ponds, downspout cisterns, dry wells, or other downspout water storage devices may also be used with prior approval by the City of Everett.These are options to consider after the above listed BMPs are evaluated. 2. Determine which options you must use for managing stormwater from hard surfaces (driveways, paved pathways, etc.) by considering the following for each type of hard surface proposed: • BMP 12.60 Concentrated Flow Dispersion • BMP 12.70 Sheet Flow Dispersion Note: Propose an alternative stormwater management plan if none of the above BMPs can feasibly be installed. (Examples:Shallow vegetated swale,perforated pipe stub-out, etc.) („Page 3 of 7.: CITY OF EVERETT 13200 Cedar Street I Everett, WA 98201 1425-257-8810 Ieverettwa.gov°`