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1 Clarks Creek Elodea Task Force Workshop 2 Alternative Solutions Minutes MINUTES NOVEMBER 7, 2012 12:00 A.M. - 7:00 P.M. PUYALLUP CITY HALL – RETAIL SPACE MEETING CALLED BY MARK A. PALMER, CITY ENGINEER TYPE OF MEETING FACILITATION – Workshop 2 FACILITATOR JIM MERRITT FAIA, MERRITT ARCH NOTE TAKER BRIAN PATNODE ATTENDEES All Stakeholders Agenda topics: Alternative Solutions DEFINING DECISION CRITERIA & ALTERNATIVE SOLUTIONS DISCUSSION General comments: We need to look at more than just Elodea (Bill Sullivan) Char Naylor displayed maps explaining the studies which have recently been conducted (will be completed at the end of December). The maps highlighted the areas where sediment samples were taken from. Studies identified the sources of the problem. 750 tons generated per year within 21 sites. At least 300 tons of sediment is from in-channel sources and is being produced by 7 to 8 of the 21 sites. Need to change the channel geometry. Several solutions were proposed, and decision criteria defined for evaluating the proposals. CONCLUSIONS Decision criteria defined; alternative solutions weighed against decision criteria. DECISION CRITERIA: 1. Must be acceptable to all stakeholders 2. Has to be legal & Can permits be obtained. 3. Sustainable - Long term viability 4. Responds to short term & long term goals 5. Implementation costs – Must be affordable 6. Practical Implementation ALTERNATIVE SOLUTION POSITIVE ATTRIBUTES NEGATIVE ATTRIBUTES CRITERIA MET A: No Action 2 & 5 B: Mechanical Weed Cutting Legal; responds to short term goals; Unacceptable to some; not a long term solution; not cost effective; unintended consequences 2, 4, 5 & 6 C: Suction Dredging – Diver Dredge Could maintain the integrity/topography of the Creek; flood reduction; removes entire plant; responds to short&long term golas; improves water quality. Multi-step/multi-year process; difficult to bid; large amt of material removal Meets all criteria but 5 is questionable. ---PAGE BREAK--- 2 D: Streamside Solutions/SandWand Removes sediment; improves fish habitat; could be used in localized area successfully; responds to short term goals. Multi-step/multi-year process; only a 42 day window; need to stabilize sediment inputs first; dewatering required; need silt collectors; additional studies required; will only work long term if upstream sediment is controlled. With conditions: 1, 4 & 6 met 2, 3 & 5 are questionable. E: Source Control – Control Sediment at the source (some attributes are both ) Essential to water quality; Improves habitat; Can reduce Elodea; will improve water quality; maintains channel capacity. Very costly; Essential to water quality; Property acquisitions could be needed; 1, 2, 3 & 6 met 4 (LT) 5 TBD F: Remove Rocks (Rip Rap) Remove 100T from 56th Avenue and Stewart Street Bridges Improve creek flow (Creek can’t flow around rocks); Increase velocity which would expose gravel; Relatively low cost solution; a natural sediment reduction; critical to the success of riparian plantings; could preserve the integrity of the bridge. May be difficult due to inaccessibility. Meets all criteria G: Riparian Plantings Increase density; provide more shade to decrease elodea; improves water quality/low dissolved oxygen levels (D.O.)/temperatures; improve habitat and in-channel sediment sources; long term solution; can possibly use grants. Will need to protect and maintain plantings; may not respond to short term goals; has to be the right type of trees (not too small, can survive the creek and weather); property owners may not participate. 1-5 met 6 H: Herbicide Will kill Elodea. Too many potential negatives Have to use large concentrations in order to be effective; chemical could harm people, animals, and other vegetation; has to be followed up with suction dredging; can’t be permitted; need to be able to control water before using toxic chemicals. FF 1,2,3 No 6 Not met I: LID (Low Impact Development, i.e. rain gardens, porous pavements, rain water harvesting) Reduces total stormwater flows, thus pollutants and sediment entering stream, improves base flow of streams by recharging groundwater Not a standalone solution; high water table; can’t be installed everywhere. All met J: Purchase Streamside Properties for habitat restoration; flood storage Reduces Properties owner risk; Allows creek to flow naturally. Expense v.s. benefit; Costly; Has to be linked to another solution; Small components must be comprehensive. 1, 5, 6 No 2, 3 Yes 4 (longterm Yes, short term No) K: Nutrient Source Control (controlling nutrients at the source) Education; Improve quality; Reduce Elodea; Improve fish habitat. Part of a solution – not standalone; Costly to convert all septic to sewer; Additional treatment required to keep septic. 1,2,3,4 Yes 5,6 ---PAGE BREAK--- 3 L: Meeker Creek Channel Restoration (restoring a meandering channel – approximately 1000 lf. Meet TMDL; Increase natural processes; improve water quality; increase habitat; removal of pollutants; remove bacteria; Efficient use of resources already in place. How is it cleaned?; Negatively affect Blue Herron Rookery. 1,2,4,5,6 Yes 3 No M: Temporary Shading (biological or physical shade to kill elodea) Shade kills elodea; short term solution; immediately effective; try targeted area? Impact private property; inhibit other/winged habitat; questionable aesthetics; vandalism; unexpected consequences. 1 No 2,6 3,5 No 4 LT-No, ST- Yes N: Conventional Dredge (horizontal dredging) Removes sediment; removes rip- rap; increased channel cap. Destroy riparian habitat; property acquisition-property impacts; high costs. 1,5,6 No 2 3 Yes 4 ST-no; LT- Yes ACTION ITEMS PERSON RESPONSIBLE DEADLINE Next workshop to Select Solutions begins December 12, 2012 N/A N/A