Amazon Basin Streamside Shading Assessment July 2019 This report was prepared by the Parks and Open Space Division of the City of Eugene’s Public Works Department Contents Introduction ............................................................................................................................................................ 3 Background and Regulatory Requirements ............................................................................................................ 3 Table 1. TMDL Listed Water Bodies and TMDL Pollutants, From the City’s TMDL Implementation Plan ......... 3 Amazon Creek Maintenance and Riparian Planting History ................................................................................... 4 Figure 1. Drawing depicting current "greenpiping" maintenance strategy (drawing by Emily Proudfoot). ....... 5 Amazon Basin Planting Summary 2014‐2018 ......................................................................................................... 6 TABLE 2. Native tree, willow and other shrub species commonly included in City planting plans. ................... 7 TABLE 3. Summary of Native Tree and Shrub Plantings...................................................................................... 8 Streamside Shading Assessment Methodology ...................................................................................................... 9 Figure 2. Example of reach planted with willow. ................................................................................................ 9 Figure 3. Screen shot of ArcGIS online showing willow inventory data for a sample reach of Amazon Creek. 10 Figure 4. Eugene Outdoors interns conducting riparian tree inventory with iPads. ......................................... 11 Figure 5. Screen shot of ArcGIS online showing tree inventory data for a sample reach of Amazon Creek. .... 12 Figure 6. Image showing location of willow lines vs. tree polygons. ................................................................ 13 Photopoint Monitoring ......................................................................................................................................... 14 Figure 7. Photo point monitoring photos taken in 2013 (left photo) and 2018 (right photo) at Polk Street. ... 14 Amazon Basin Planting opportunities ................................................................................................................... 14 TABLE 4. Proposed Tree Planting Project Timeline and Locations for 2020‐2024 ............................................ 15 Summary ............................................................................................................................................................... 17 Contact Information .............................................................................................................................................. 17 Acknowledgements ............................................................................................................................................... 17 Appendix A. Amazon Basin Maps ...................................................................................................................... 18 Appendix B. Amazon Creek Photopoint Monitoring ......................................................................................... 19 2019 Amazon Basin Streamside Shading Plan July 2019 2 Introduction Since 2002, the City of Eugene has planted over 4,170 trees and plugged willows along 102,791 linear feet of Amazon Creek and its tributaries to enhance streamside shading. The purpose of this document is to provide the following: brief regulatory and historic context to the City’s streamside shading efforts, a summary of the riparian plantings that have taken place along the Amazon Creek and its tributaries since the 2014 Amazon Basin Streamside Shading Assessment, and a list of priority reaches to target for streamside shading over the next five years. This document is intended primarily as an in‐house tool to document and guide streamside shading efforts by the City of Eugene’s Park and Open Space Division. Background and Regulatory Requirements In Eugene, the Willamette River, Amazon Creek and several of its tributaries do not meet certain water quality standards for parameters including bacteria, mercury, temperature, dissolved oxygen and turbidity. In 2006, as required by federal Clean Water Act, the Oregon Department of Environmental Quality (DEQ) established Total Maximum Daily Loads (TMDL) for these impaired waterways (Table 1) and received approval from the EPA for the Willamette Basin TMDL. In 2008, the City of Eugene in turn received approval from DEQ for its TMDL Implementation Plan. This plan, required by all municipalities and agencies that discharge water (e.g. stormwater, treated wastewater) into impaired waterways, described measurable actions that, when implemented, would allow the City to meet pollution reduction goals within its jurisdiction. As part of this initial plan, the City committed to planting 4,000 linear feet of willow and 400 trees annually along Amazon Creek, to meet the streamside shading goals. Between 2008 and 2014 a total of 2,900 trees and nearly 63,000 linear feet of willow were planted along Amazon Creek, primarily on City‐owned reaches. Table 1. TMDL Listed Water Bodies and TMDL Pollutants, From the City’s TMDL Implementation Plan Subbasin Waterbody Name River Miles Parameter Season Upper Willamette Willamette River 50.6 to 186.5 Temperature Year Round Upper Fall/Winter/ Willamette Willamette River 0 to 186.4 Bacteria Spring Upper Willamette Willamette River 174.5 to 186.4 Mercury Year Round Upper mouth to Willamette A3 Channel headwaters Bacteria Year Round Upper Willamette Amazon Creek 0 to 22.6 Bacteria Year Round Upper Amazon Creek Willamette Diversion Channel 0 to 3.5 Bacteria Year Round Upper Amazon Creek Willamette Diversion Channel 0 to 3.5 Mercury Year Round 2019 Amazon Basin Streamside Shading Plan July 2019 3 Upper Amazon Diversion Spring/Summer/ Willamette Channel 0 to 1.8 Dissolved Oxygen Fall Upper Fern Ridge Reservoir Fall/Winter/ Willamette /Long Tom River 0 to 24.2 Bacteria Spring Upper Fern Ridge Reservoir 24.2 to 31.8 Turbidity Year Round Willamette /Long Tom River Upper Willamette Long Tom River 0 to 24.2 Temperature Summer In 2014 the City submitted its TMDL Fifth Annual Report and Review to DEQ for review. That document was reviewed and accepted as the City’s Updated TMDL Implementation Plan. Included in the five‐year report was the first Amazon Streamside Shading Assessment, which summarized previous planting efforts, evaluated the success of those plantings, and identified additional streamside shading opportunities. This first ever summary of the City’s riparian planting efforts showed that most of the high priority (south and west banks), City‐owned reaches of Amazon Creek had been planted. It also indicated that streamside trees were taking a long time to mature and that shifting some of the focus to the maintenance of past plantings was warranted. As a result, the 2014 Updated TMDL Plan included several changes related to the streamside shading goals. Specifically, the new plan calls for planting 200 trees and 2,000 linear feet of willow along waterways within the Amazon Basin. This includes tributaries such as the A‐2 and A‐3 Channels, Roosevelt Channel, and other smaller waterways, in addition to Amazon Creek. The new plan also added an activity aimed at enhancing streamside shading on private property in the Amazon Basin by coordinating with partner such as the Long Tom Watershed Council (LTWC). In December of 2018, the City submitted its TMDL Year 10 Report, which includes a five‐year review that once again provides opportunities for the City to propose changes to the TMDL Plan for the upcoming five‐year period. Until that is approved by DEQ, the City will continue to operate under the 2014 Updated TMDL Implementation Plan. For more detailed information on the City’s TMDL Plan please visit www.eugene‐or.gov and navigate to the NPDES Municipal Stormwater Permit page. The list of links on the right‐hand side of the page includes a link to the current TMDL plan near the bottom. Amazon Creek Maintenance and Riparian Planting History Most of Amazon Creek and its tributaries that occur in the valley floor of Eugene are highly modified urban streams that were channelized in the 1950s by the Army Corps of Engineers as part of the Amazon Creek Flood Damage Reduction Project. The channelization created waterways that are generally disconnected from their floodplains and in many cases were armored with rock to reduce erosion and insure conveyance. In most places, the upper banks along these modified creeks consist of rocky, poor quality soils that appear to be made up of the material that was dug from the channel bottoms. This results in banks that are well drained and are perched well above summer water levels, making the establishment of riparian trees challenging. Furthermore, up until the late 1990s, waterway maintenance practices had a single objective of ensuring maximum conveyance capacity. This consisted primarily of excavating the banks and bottoms of open waterways to bare soil using 2019 Amazon Basin Streamside Shading Plan July 2019 4 large mechanized equipment to remove any debris, sediment and vegetation which might be deemed an impedance to flow or that would reduce the cross‐sectional area of the waterway. These practices certainly did not allow for the