Lake management committee confirms fluridone treatment this spring; boat-launch permit and contract amendment still pending city approval

The City of Tumwater Lake Management District steering committee said it will proceed with a full-lake fluridone herbicide treatment this spring and is coordinating a temporary widening of an existing private boat launch to accommodate the contractor's airboat and survey boat.

Committee members said the contractor, Scott (contractor, not present), is planning the fluridone application for May, with a lake survey the week before. Committee member comments described the planned application as a whole-lake treatment rather than a spot treatment and said the contractor will use two boats: a smaller skiff for surveying and an airboat with a larger tank for herbicide application.

The committee emphasized that fluridone works best when target plants are actively growing. City staff noted the contractor will “do a survey a week prior” to check plant growth and distribution, and the committee discussed that the treatment strategy and frequency depend on shallow-depth mixing and plant growth rather than a single-day temperature threshold.

Why it matters: The fluridone plan affects budget, permitting and access. The committee said the city needs to finalize permitting for widening the private launch used under an agreement with a property owner (Dana) and to confirm whether the boat ramp work or temporary arrangements will be ready for the May schedule.

Details and council/administration steps: Committee members reported a previous vote (taken at an earlier meeting) to proceed with fluridone. They also discussed a pending contract amendment with Aquatechnics (contractor name appears in materials with inconsistent spelling) to include the fluridone work; staff said they plan either a contract amendment routed through city council or an administrative approval if the city changes director signature limits. The committee said city director Dan currently can sign contracts under $50,000 but the city is working to raise that delegation to $100,000; if that administrative change completes in time the amendment could be executed without council authorization, otherwise staff will seek early-May council action.

Boat launch and site work: Members said the airboat's trailer and wheels are wider than the existing ramp configuration; the committee is preparing permit materials (site photos and construction details) and reported a permitting fee shown in materials of $1,080. The committee discussed a temporary boat-launch approach if the ramp work is not complete by the contractor’s schedule; staff said the contractor is comfortable with a temporary launch and the city has an existing short-term agreement with property owner Dana for launch use and maintenance in exchange for a waived assessment fee.

Discussion versus decision: The committee framed the fluridone treatment and boat-launch widening as actions they plan to proceed with, but committee members stated the fluridone contract amendment and some site work remain conditional on city permitting and on whether administrative signature limits are changed. The earlier vote to proceed with fluridone was referenced as already taken; no new formal contract award or budget appropriation vote occurred in this meeting.

Technical and cost notes: A committee member said maintaining a target concentration (described in discussion as an example “4 parts per million”) is needed and that repeated applications may be required in-season to maintain control, depending on dilution and wave action. Committee members described fluridone as “very expensive” and said annual follow-up treatments (diquat for lilies and annual spot work) would still occur.

Next steps: Staff will finalize permit materials for the boat ramp, coordinate with the contractor on launch logistics and timing, and pursue either a council agenda item or an administrative contract amendment depending on the city’s signature-limit change. The committee expects the contractor’s pre-treatment survey a week before application and said it will track whether additional in-season follow-up is required.