CITY OF SEATTLE
ORDINANCE __________________
COUNCIL BILL __________________
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AN ORDINANCE relating to the Cedar River Municipal Watershed; amending the Secondary Use Policies, adopted by Ordinance 114632, to provide for the limited application of the herbicide imazapyr to treat invasive knotweed species.
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WHEREAS, the Cedar River Watershed Secondary Use Policies, adopted by Ordinance 114632, include a moratorium on herbicide use to prohibit the routine broadcast application of herbicides for control of roadside vegetation in lieu of brushing, and invasive plant species were not a consideration in watershed land management practices when these Policies were adopted in 1989; and
WHEREAS, from 2002 through 2010, Seattle Public Utilities attempted to control knotweed using physical means, including covering with geotextile fabric and digging, but even small patches of knotweed are exceedingly difficult to control by physical means, and treating knotweed with herbicide has been found to be the only effective way to control large patches; and
WHEREAS, uncontrolled knotweed in 2010 covered nearly 18 acres of land in the Cedar River Municipal Watershed and was spreading at rapid rate, displacing native species, eroding stream banks, threatening water quality, and destroying biodiversity; and
WHEREAS, on August 6, 2010, a limited exception to the Secondary Use Policies was authorized by Ordinance 123365 to allow the application of the herbicide imazapyr
to control or eradicate knotweed species in the Cedar River Municipal Watershed through December 31, 2012, and two follow-up limited exceptions to the Secondary Use Policies were authorized by Ordinances 124191 and 124852 to continue to allow application of the herbicide imazapyr through December 31, 2015, and December 31, 2018, respectively; and
WHEREAS, Seattle Public Utilities’ method of applying a one percent imazapyr solution to knotweed from midsummer to fall is in line with King County Noxious Weed Control Program’s Best Management Practices; and
WHEREAS, imazapyr inhibits an enzyme found only in plants, and the U.S. Environmental Protection Agency rates imazapyr as being relatively non-toxic to birds, mammals, fish, and invertebrates, and a United States Forest Service toxicology study determined imazapyr causes no measurable adverse effects on fish and wildlife; and
WHEREAS, the amount of herbicide applied in the Cedar River Municipal Watershed has decreased from 26.9 ounces per acre in 2011 to 0.4 ounces per acre in 2018, which reflects the large drop in above-ground knotweed biomass during this treatment period, but knotweed re-infestation will occur without continued, limited use of imazapyr through 2021; NOW, THEREFORE,
BE IT ORDAINED BY THE CITY OF SEATTLE AS FOLLOWS:
Section 1. Cedar River Watershed Secondary Use Policy 6-13, last amended by Ordinance 124852, is amended as follows:
Seattle Public Utilities will continue the herbicide moratorium, controlling undesirable vegetation with hand or mechanical methods, except that the following exemption for the use of ((Imazapyr)) imazapyr shall apply through December 31, ((2018)) 2021. ((The Director of)) Seattle Public Utilities is ((hereby)) authorized to apply ((Imazapyr)) imazapyr for the purpose of controlling or eradicating knotweed species within the Cedar River Municipal Watershed in accordance with the methods and procedures established in this section and all applicable state and federal drinking water source protection standards. Seattle Public Utilities will adhere to ((the application method and monitoring described in Attachment 1: A Proposal to Continue to Use Herbicide to Manage the Knotweed Infestation in the Cedar River Municipal Watershed, April 21, 2015)) targeted foliar application methods that use a one percent imazapyr solution applied directly to knotweed leaves with backpack or handheld sprayers. Herbicide will be applied by licensed pesticide applicators or those under direct supervision of licensed applicators. Seattle Public Utilities will monitor knotweed treatment areas annually and will monitor water quality before and after herbicide application. Seattle Public Utilities will provide the ((Seattle Public Utilities and Neighborhoods Committee of the City Council, or successive committee,)) Civil Rights, Utilities, Economic Development and Arts Committee of the City Council or successor committee an annual report on the knotweed treatment program in the Cedar River Municipal Watershed, summarizing the effectiveness of the knotweed treatment program, evaluating the long-term financial and environmental implications for knotweed control beyond ((2018)) 2021, evaluating the water quality monitoring results, summarizing the latest available science on the environmental and human health effects of ((Imazapyr)) imazapyr, and describing any plans for the future ((application)) use of ((Imazapyr)) imazapyr within the Watershed, including maps of proposed treatment areas, estimated quantities of ((Imazapyr)) imazapyr to be applied, application methods and schedules, and plans for water quality monitoring. ((The Director of)) Seattle Public Utilities may authorize ((application)) use of ((Imazapyr)) imazapyr to newly-discovered areas of knotweed infestation, but ((the)) use ((of Imazapyr)) on newly-discovered areas located within the hydrographic boundary may not exceed five acres in size.
Section 2. The General Manager/CEO of Seattle Public Utilities shall ensure that areas formerly occupied by knotweed are restored to native vegetation.
Section 3. The General Manager/CEO of Seattle Public Utilities shall continue the ongoing program for monitoring, detecting, and controlling invasive plants in the Cedar River Municipal Watershed with a goal of preventing colonies of knotweed from re-establishing.
Section 4. This ordinance shall take effect and be in force 30 days after its approval by the Mayor, but if not approved and returned by the Mayor within ten days after presentation, it shall take effect as provided by Seattle Municipal Code Section 1.04.020.
Passed by the City Council the ________ day of _________________________, 2019, and signed by me in open session in authentication of its passage this _____ day of _________________________, 2019.
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President ____________ of the City Council
Approved by me this ________ day of _________________________, 2019.
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Jenny A. Durkan, Mayor
Filed by me this ________ day of _________________________, 2019.
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Monica Martinez Simmons, City Clerk
(Seal)