Capacity-constrained is defined by the Stormwater Code, SMC 22.801.040 as “a drainage system that the Director of SPU has determined to have inadequate capacity to carry drainage water". There are three distinct areas that compromise what is currently mapped as capacity-constrained, 1) the entire network comprising the informal drainage system consisting of the intermittent ditch and culvert network – as these were never engineered, they are inherently capacity constrained. 2) The infrastructure contained in the Densmore Basin which discharges to a King County storm drain which was not designed with capacity to convey runoff from the increased density from additional development. 3) a portion of the public storm drain system on Capitol Hill upstream from the maintenance hole at the intersection of Pike St & Melrose Ave, there is a hydraulic restriction in this maintenance hole which leads to an extremely elevated hydraulic grade line and associated localized surface flooding. For more information on this Code please see, http://water.epa.gov/polwaste/nps/upload/nps-ordinanceuments-seattle-code.pdf

This layer displays all the sandboxes and junction boxes within the City of Seattle (and the former service area north of the City limits) regardless of ownership. Selected Maximo data are included. The data source is DWW.catch_basin_pt_pv with the following definition query, CB_LIFECYCLE_CODE IN( 'C' , 'UNK' , 'T' ,'TBC', 'U', 'PC') AND CB_FEATYPE_CODE IN ( 'SB' , 'JB', 'JBS'). The features are symbolized on the attribute CB_FEATYPE_CODE. Labels are based on the attribute CB_ROLE_TYPE. This layerfile does not display when zoomed out beyond 1:899. Refreshed weekly. Maintained by SPU GIS DWW Data Maintenance staff.

The data source is from official City surveys, calculations and other publicly recorded documents.  Displays data from CADASTRAL.CONTROL_LN_PV.  Data does not display when zoomed out beyond 1:38,000.