2119 LOMBARD AVE 2023-05-30 - Laserfiche WebLink

Stormwater Report Dated 4-27-21 Prepared for: Dwyane and Kassidee Younglut at 2119 Lombard Avenue For The Existing Single-Family Home and Proposed Detached ADU Narrative: This report is designed to address the volume and flow control of the roof run off of the existing existing single-family home and the detached ADU located at 2119 Lombard Avenue SE. The lot size is 0.14 acres (6,098 square feet) with one existing single family home and domestic landscaping (see attached aerial). The existing single family home has a total coverage of 1,296 floor and the proposed DADU has a total coverage of 1 ,274 sf. See submitted site plan and TESC plan. Existing and Proposed Land Use Covers: The site plan on Sheet 2 provides the hard surface generation areas and describes the existing and proposed land use covers (types). In summary, the existing single family home generates unpolluted runoff which is routed from the roof down a downspout to a splash block which is then infiltrated on-site. The same system is proposed for the new DADU. The existing ground cover where the DADU is located is currently grassed. The new DADU will create a non-polluting hard surface which will be utilizing downspouts and splash blocks to a grassed area to be infiltrated into the groundwater system. This runoff will be separated and not contributing to the combined sewer/runoff system. The same treatment of the roof runoff is proposed for the new DADU. Treatment and Maintenance of Stormwater Roof Runoff System: The homeowner will be responsible for the cleaning and maintenance of the gutters, downspouts and splash blocks. The area around the splash blocks will be a grassed to allow any sedimentation contained in roof runoff to be separated prior to entering the groundwater. No additional runoff will be discharged into the combined sanitary sewer/stormwater system.