Department of Natural Resources uses digital photography to map impervious surfaces for more accurate stormwater billing.

Stormwater treatment infiltration pond next to Evans Creek. Infiltration systems on sensitive Evans Creek properties will be more closely monitored by the City.

UPDATED, 5/21. Opinion: The council voted (7-0) last night to modify stormwater billing to improve billing accuracy. New digital aerial mapping technology allows stormwater engineers to more accurately identify all impervious surfaces (roads, parking, structures) that contribute to dirty stormwater run-off. According staff, an "opt-out" condition only applies to the city-center (downtown) sub-basin, and is only applicable to properties within that sub-basin that are adjacent to the Sammamish River. No change in treatment requirements will apply from this ordinance.

The SW industrial businesses (R.I.C.E.) earlier had lobbied for "infiltration" and against regional treatment improvements. Staff is working with RICE to develop an assessment for existing infiltration systems, and to develop a process and timeline to modify existing systems (if necessary) to reduce risk to the aquifer. The City is building a SW Regional Treatment Plant to treat dirty stormwater more comprehensively and economically along the industrial district of Evans Creek and SW Redmond. Councilmembers Hank Myers and Pat Vache' lended their support to the R.I.C.E. industries during negotiations.

The Administration made some concessions to pass the modification. With staff approval, industries and landowners living adjacent the river would be allowed to "opt out" from hooking into the new Downtown Regional Stormwater Facility. To qualify for reduced rates, a professional engineer would have to make sizing and cost estimates for properties building a private water treatment facility. Department of Ecology water quality standards must still be met. A business could "opt out" for lower rates if their plan was approved by the Staff. Another concession, driven by Myers, was to allow businesses to appeal their bill by October, 2009. Landowners who "opt out" will be reimbursed for the value of their land lost to an on-site facility. Finally, staff had requested that "gravel" count as an impervious surface. The Administration and council decided not to include gravel as impervious, but to study and decide on the issue by December, 2010.

The new digital photography mapping techniques to identify parcels with impervious surfaces is more accurate than on site visits. 78 letters have been mailed to property owners with NEW stormwater bills. Also, the unit measurement of impervious has been "truncated" which will bring higher revenues to the city. In addition, billing by parcel, rather than property owner will add to revenues. Credits will be given for "rain harvesting".

Public Works Director Bill Campbell and Stormwater Manager Jon Spangler, have been progressive and innovative in meeting city needs for cleaner water, all the while, dancing the political jig for council and property owners. Councilmember Hank Margeson concluded the billing modification was really all about cleaner water for our streams (and aquifer zones). Margeson Chairs the Planning & Public Works Committee.

Link to the Modified Stormwater billing ordinance

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