Agriculture Resilience Plan for Snohomish County
Prepared by: Snohomish Conservation District
December 2019 COVER PHOTO CREDIT: Lorenzo Townsend, Snohomish Conservation District, 2019. Agriculture Resilience Plan for Snohomish County
Prepared by: Snohomish Conservation District 528 91st Avenue Northeast Lake Stevens, WA 98258
December 2019 Agriculture Resilience Plan
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Table of Contents
Table of Contents ...... iii
Acknowledgements ...... v
Executive Summary ...... vii Figure E-1. Plan Study Area ...... ix
Chapter I . Introduction ...... 1. . . .
Chapter II . Outreach and Engagement ...... 5 . . .
Chapter III . Farmland Conservation ...... 7 Table III-1. Farmland Prioritization Acreage ...... 9 Figure III-1. Snohomish County Farmland Conservation Priorities ...... 11
Chapter IV . Resilience Practices ...... 13
Chapter V . Impacts Assessment ...... 17 Table V-1. Projected Extent of Flooding ...... 18 Table V-2. Projected Days Per Year Stage Thresholds are Exceeded ...... 19 Table V-3. Relative Sea Level Rise Projections ...... 19 Figure V-1. SLR Delay to Spring Crop Cultivation, Snohomish Watershed, Year 2050 ...... 27 Figure V-2. SLR Delay to Spring Crop Cultivation, Snohomish Watershed, Year 2100 ...... 28 Figure V-3. SLR Delay to Spring Crop Cultivation, Stillaguamish Watershed, Year 2050 ...... 29 Figure V-4. SLR Delay to Spring Crop Cultivation, Stillaguamish Watershed, Year 2100 ...... 30 Figure V-5. Projected Depth-to-Groundwater Map for Ebey Island and Vicinity ...... 31 Figure V-6. Future Conditions Depth-to-Groundwater Map for Ebey Island and Vicinity 32 Figure V-7. Early Summer Salinity Intrusion to Groundwater ...... 33
Chapter VI . Priority Needs ...... 37 . . .
Chapter VII . Reach Summaries ...... 41 . . . . Figure VII-1. Stillaguamish River floodplain reaches 42 Figure VII-2. Snohomish River floodplain reaches 43 Figure VII-3. Map of Drainage District 7. 44
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Figure VII-4. Map of the Stillaguamish Flood Control District. 47 Figure VII-5. Map of Middle Stillaguamish River floodplain...... 51 Figure VII-6. Map of North and South Forks of the Stillaguamish River floodplain...... 54 Figure VII-7. Map of Diking Districts 2 and 4...... 56 Figure VII-8. Map of Diking District 1 – Ebey Island. 60 Figure VII-9. Map of Drainage Improvement District 13. 64 Figure VII-10. Map of Marshland Flood Control District...... 68 Figure VII-11. Map of French Slough Flood Control District...... 72 Figure VII-12. Map of the Snohomish River Confluence...... 76 Figure VII-13. Map of Lower Skykomish River floodplain. 79
Chapter VIII . Next Steps ...... 83. . . .
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Acknowledgements
STEERING COMMITTEE Funding NOAA Community Based Restoration Program Andrew Albert, Andrew’s Hay Stillaguamish River Lead Entity Dan Bartelheimer, Sno-Valley Farms Estuary and Salmon Restoration Program Brian Bookey, Cherry Lane Farms EPA National Estuary Program Darren Carleton, Carleton Farms Floodplains by Design Jeff Ellingsen, SCD Board Member and Farmer Spencer Fuentes, Hazel Blue Acres Recommended Citation Nick Pate, Raising Cane Ranch Libby Reed, Orange Star Farm and SCD Board Member Snohomish Conservation District, 2019. Agriculture Jeremy Visser, dairy farmer Resilience Plan for Snohomish County. Lake Stevens, Washington. PROJECT TEAM Snohomish Conservation District Cindy Dittbrenner, Project Manager Carrie Brausieck Bobbi Lindemulder Brett DeVries Ryan Bartelheimer Kristin Marshall Eric Schuh Kari Quaas
CONTRIBUTORS University of Washington Climate Impacts Group (Guillaume Mauger), Washington State University Center for Sustaining Agriculture and Natural Resources (Kirti Rajagopalan), PCC Farmland Trust (Robin Fay, Hilary Aten), and The Nature Conservancy (Heather Cole, Jamie Robertson).
CONSULTANT TEAM Cardno (Dan Elefant, Sky Miller), Fathom (Andrew Smith), ESA (Spencer Easton)
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“A bee works its essential magic in the blueberry blossoms, sharing the hope and promise of another summer of organic, antioxidant rich blueberries at Hazel Blue Acres.”
Karen Wolden-Fuentes, Hazel Blue Acres Farm, Photovoice 2017
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Executive Summary
This Agriculture Resilience Plan is a plan guided by and developed for the local farming community in Snohomish County. The Plan will help build a more resilient Agriculture in agricultural landscape – one that can withstand pressures Snohomish County and changes associated with development, population growth, flooding, shifts in weather and climate change. — Over 63,000 acres of active farmland Through a combination of information gathering and — 1,558 farms sharing, creation of online planning tools, project scoping and design, project implementation, and farmland — Farms as large as 2,000 acres protection, the Agriculture Resilience Plan will help ensure local agriculture remains a cornerstone of our way of life — Agricultural products selling for over and value system in Snohomish County. $157 million per year
Source: United States Department of Agriculture “The Agriculture Resilience Plan is an effort to help all of us farmers Agricultural resilience can be improved by helping farmers weather the changes that are coming plan for future challenges and risk, absorb future change, in the future. It’s a way for farmers to and more quickly recover from stress. raise their voices together and create The Agriculture Resilience Plan is linked to the work of change to benefit agriculture.” the Snohomish County Sustainable Lands Strategy (SLS). SLS, started in 2010, is a collaborative effort of partners Libby Reed, Orange Star Farm working to improve coordination and generate progress for fish, farm, and flood management in the Snohomish The goals of the plan are to: and Stillaguamish watersheds. As a participant in SLS, the Snohomish Conservation District identified a gap • Provide information and project funding for farmers to in the scientific understanding of agricultural needs, manage for future risk on their farms particularly as they relate to climate change, as well as • Develop landscape-scale projects to improve an organized planning approach to developing priority agricultural resilience landscape-scale projects. This Agriculture Resilience Plan is intended to fill this data gap and identify priority • Protect agricultural lands from subdivision or resilience projects that will keep Snohomish County’s development agricultural lands viable into the future.
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Need for Resilience How the Agriculture Resilience Despite the increasing importance of and need for local Plan was Developed farming in Snohomish County, agriculture is threatened by development and environmental changes. The United The Agriculture Resilience Plan is intended to be the States Department of Agriculture noted that farm sector farmers’ plan – a document that reflects the interests profits declined by $9.8 billion from 2017 to 2018 across and priorities of farmers in Snohomish County. Therefore, the country. This represents 13 percent of the profits from outreach to and engagement with farmers and the farming. Production expenses are forecast to increase by farming community has been a key component of $11.8 billion due to increases in costs for fuel, feed, and developing this plan and will continue to be central to its hired labor. Finances are just one of the pressures facing implementation. Input from farmers has been solicited farmers. American Farmland Trust has identified that 175 through the formation of a Steering Committee of local acres of farm and ranch land in the United States are lost farmers, outreach to existing agricultural groups and to sprawl and development every hour, while 1.7 billion individual farmers, and a photo documentation project tons of topsoil are lost to erosion each year. These trends called PhotoVoice. and pressures also affect Snohomish County farms. Everett is one of the fastest growing cities in Washington Snohomish Conservation District formed a Steering State, and the rising cost of land makes it difficult for Committee for the Agriculture Resilience Plan in order farmers to stay in the county. to ensure that the plan is guided by the input of local farmers. The Committee is comprised of 9 Snohomish In addition to the existing economic and development County farmers representing various types, sizes, and pressures on agriculture, climate change will present locations of farms. The Steering Committee met quarterly additional challenges into the future. In Snohomish to provide guidance on the direction and development of County, sea level rise is expected to lead to saltwater the plan. intrusion and rising groundwater tables. A changing climate will cause drier summers, wetter winters with In addition to soliciting guidance from the Steering more intense storms, and increased river flooding. Committee, the Conservation District conducted Land subsidence and riverbank erosion are expected to extensive outreach to the local farming community. In continue and increase. fall 2016 and winter 2017, the Conservation District reached out to existing agricultural groups to ask for input into the scope of this project. Groups included the Snohomish Conservation District Board of Supervisors, Focus on Farming attendees, the Sustainable Lands Strategy Agriculture Caucus, the Snohomish County Farm Bureau, Snohomish County Cattlemen, the Snohomish County Agricultural Advisory Board, SnoValley Tilth, the Coordinated Diking Council, the Marshland Flood Control District, the French Slough Flood Control District, and the Stillaguamish Flood Control District.
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I-5 Map Skagit County Detail
WA
Stanwood Darrington
Arlington
Marysville Granite Falls
S n o h o m i s h C o u n t y C h e l a n Lake Stevens C o u n t y
Everett Snohomish Watershed Boundaries Mukilteo P u g e t Monroe Sultan Stillaguamish S o u n d Mill Gold Bar Snohomish Creek Lynnwood Snohomish County is the Edmonds US 2 Bothell boundary of the plan and additional focus was given to Mountlake the resilience needs of the Terrace primary commercial farming K i n g C o u n t y areas highlighted in orange. 0 10 Miles ±
Figure E-1 . Plan Study Area . This map shows the study area for the Plan, which includes all of Snohomish County with a focus in the key floodplain agriculture reaches in orange.
In spring 2019, the Conservation District launched STEERING COMMITTEE MEMBERS a broader community engagement effort, primarily • Andrew Albert, Andrew’s Hay focusing on commercial farmers in the river floodplains. • Dan Bartelheimer, Sno-Valley Farms Presentations were given for local diking, drainage, and • Brian Bookey, Cherry Lane Farms flood control districts and community meetings were • Darren Carleton, Carleton Farms organized outside of these areas. The goals of this effort • Jeff Ellingsen, SCD Board Member and Farmer were to provide localized results from the risk modeling • Spencer Fuentes, Hazel Blue Acres and assessment work and to gather feedback on • Nick Pate, Raising Cane Ranch resilience needs and potential projects. This information • Libby Reed, Orange Star Farm and SCD Board Member was used to create Reach Summaries that were then • Jeremy Visser, dairy farmer reviewed and revised by the farming community in summer 2019.
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Impacts Assessment SUBSIDENCE AND AGGRADATION The analysis of farmland subsidence for both the To understand the impacts of climate change on Stillaguamish and the Snohomish River floodplains agricultural land in Snohomish County, the Conservation indicated that some areas may be sinking 2-3 inches per District initiated technical studies on flooding, decade due to cultivation of organic soils, although error groundwater levels, saltwater intrusion, land subsidence rates in this study are high. and aggradation, and crop impacts. Key take-aways from each technical study are listed below. The studies are The Lower Stillaguamish River channel is aggrading, and summarized in Chapter V of this plan, and full studies can this trend is likely to continue into the future. The Lower be found on the Conservation District website at https:// Snohomish River is not aggrading in general, but upper snohomishcd.org/impact-assessment. reaches (from the SR-9 bridge to the Skykomish River) show some aggradation. FLOODING Increases in the extent of flooding will put additional CROPS farmland at risk of inundation, particularly during more Increasing air temperatures in summer months are frequent storm events (such as the 2-year and 10-year projected to negatively impact some existing crops while floods). Thousands of additional acres will be flooded on at the same time providing opportunities for new types a 2-year event by mid-century and critical stage heights of agricultural production. This warming will result in a will be exceeded more frequently each year. longer growing season but also an accelerated growing degree day accumulation, which can have a negative impact on yields. Models project a decrease in summer GROUNDWATER precipitation and an increase in winter precipitation. Rising sea levels are anticipated to delay the time when estuary farmers can access their fields in the spring by up By the 2040s, Snohomish County is predicted to have to three weeks by the 2050s and up to five weeks by the similar growing conditions to Santa Cruz County, CA, 2080s. just south of San Jose. And by the 2080s, conditions are expected to be most similar to Santa Barbara County, SALTWATER INTRUSION CA, just north of Los Angeles. Areas closest to the shoreline are at the highest risk of saltwater intrusion. Areas within 5,000 feet of the shoreline are especially vulnerable, and areas within 10,000 feet could also experience increases over time.
Florence Island, in the Stillaguamish River estuary, already experiences saltwater intrusion above crop tolerance thresholds in patches, and those impacts are likely to increase in severity over the next 50 years. Increasing pumping could pull salty water upward in the groundwater table.
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systems. Many agricultural areas require a drainage Priority Needs needs assessment to inform projects that would increase The agricultural community in Snohomish County is capacity of existing culverts, tide gates, and pump facing many current and projected challenges associated stations as well as replace aging infrastructure. with increased development and a changing climate. Through a robust community engagement process, COMPENSATION FOR UPLAND RUNOFF farmers provided priority resilience needs. Addressing Development of upland areas has resulted in increased these resilience needs will require partnership building, runoff reaching our floodplains, in many cases innovative approaches to problem solving, and funding exacerbating drainage challenges for farmers. Some acquisition. Farmers highlighted the need for grant and/or diking, drainage, and flood control districts have loan funding to address many of these issues described agreements with local jurisdictions to collect stormwater below. fees to help offset the costs of this increased runoff and sediment, yet most do not. There is a need to work FARMLAND CONSERVATION with individual districts and local jurisdictions to help Much of Snohomish County’s commercial farmland develop these compensation agreements and potentially is in the floodplain, where state and local regulations increase revenue under existing agreements. Projects provide partial barriers to conversion of the land. Still, or initiatives to reduce upland runoff would also greatly many farms in both the floodplains and upland areas benefit farmers. These include use of green stormwater continue to be lost to development, habitat restoration, infrastructure, regulatory changes to county and city and other uses. Existing funding sources are insufficient development codes, and education of or incentives for to reach conservation targets or satisfy farmer interest. urban and suburban landowners to reduce runoff from Potential options for increasing funding available include their properties. augmentation of the Transfer of Development Rights program at Snohomish County, as well as additional grants and/or taxes.
DRAINAGE INFRASTRUCTURE IMPROVEMENTS Diking, Drainage, and Flood Control Districts across the County consistently report insufficient funding to manage current drainage needs, citing runoff from upland areas and increased flooding as major contributors. Climate change projections indicate increased winter flood frequency and scale, highlighting the need for improvements to and increased capacity of drainage
Farmers Helping Farmers “Collaboration is a big part of farming on a small scale. Farmers need opportunities such as the Tilth to work together and learn from each other. Farms might benefit from a grown-in-Snohomish County brand. This would help consumers recognize when they are buying locally.” Anna Caruso, Caruso Farm, Photovoice 2017
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FLOOD PROTECTION ADDITIONAL GROUNDWATER ANALYSIS While farms in the floodplain are often inundated in Further study of groundwater levels and saltwater winter months, damages are minimized and spring intrusion are recommended in the estuaries of the drainage made possible through a system of sea dikes, Stillaguamish and Snohomish Rivers to validate river levees, and riverbank protection projects. In many predicted impacts of sea level rise on farmland. In places, this flood protection infrastructure is in need of particular, additional data collection and analysis has improvements or replacement, and in others, there is been recommended for Florence Island and Drainage a need for additional protection. With flood frequency District 7 in the Lower Stillaguamish River floodplain and and severity predicted to increase, impacts to this Ebey Island and Diking Districts 2 and 4 in the Lower infrastructure will increase. Snohomish River floodplain.
ACCESS TO IRRIGATION WATER Many farms do not have legal water rights yet have a While the intent of this Agriculture Resilience Plan is to need for irrigation water to maintain their viability. Climate focus on needs and actions to make the agricultural change predictions indicate the need for irrigation water land itself more viable and resilient to future change, will increase with less precipitation falling in summer farmers also provided valuable feedback on other market, months and increasing temperatures. At this time, new research, and education-related needs. These include: water rights are not available for farmers. There is a need for creative approaches to providing access to water. • Assistance complying with regulations – The costs Potential options include on-farm water storage or the of and time associated with complying with county and coordinated management and leasing of water rights at a state regulations puts incredible pressure on farmers, landscape scale. particularly smaller operations.
• Research into new crop varieties – The impacts of “We may have enough water now but changing land use, climate, and markets continues we may not have enough in five years. to necessitate research into crop varieties that are We need to be looking to the future.” resilient, drought tolerant, salt tolerant, and/or slower to mature. – Jesse Allen, farmer • Flood risk training for new landowners – New farmers moving into the floodplain could benefit ASSISTANCE IMPLEMENTING DROUGHT greatly from training on how to minimize flood risk by RESILIENCE PRACTICES accessing flood data and predictions available through There are numerous techniques that can be used to Snohomish County and preparing for floods. increase a farm’s resilience to drought or to reduce the need for irrigation. Existing incentive and grant programs through the state and federal government provide cost-share funding for practices that build soil water holding capacity, hold and/or store water, and increase irrigation efficiency. These programs, however, are often highly competitive or pay low rates. With climate predictions indicating hotter and drier summers, additional funding, research, and on-farm trials are needed to incentivize new practices.
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Next Steps This Agriculture Resilience Plan for Snohomish County will help ensure the viability of our farmlands into the future. The next step is to continue to work together as an agricultural community to implement the actions included in this Plan. The Steering Committee recognizes that these actions cannot be achieved without collaboration and partnership. The needs represented in this plan, therefore, are a starting point for collaborative thinking with partners, communities and government bodies about how we manage our land and our natural resources in a time of changes and uncertainty.
Implementation of the Agriculture Resilience Plan will involve the following:
• Project scoping and design
• Coordination with SLS partners
• Funding procurement for project implementation and farmland conservation
• Continued education to local farmers
• Partnership building
Growing a Thriving Local Food Culture “Inspiring and supporting the future generation of farmers and eaters is really what it is all about. The excitement in this kiddo’s eyes as she proudly holds up her veggies, fresh from the field, is energizing for us. We want to grow a food culture in our community that shares this excitement and pride in fresh, healthy, local food that tastes great and allows the farming community to thrive here as well.” Chelsea Johansen, Rainy Sunday Ranch, Photovoice 2017
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Hands on Farming “We are a small farm, a husband and wife team. If it needs prepped, seeded, weeded, planted, irrigated, transplanted, harvested, packed, marketed, or sold, we do it, all of it. We do almost all of it by hand, both out of necessity and preference. We enjoy being in close contact with the soil, with our farm, with our customers. We see value in small farms that are dedicated to being sustainable and relevant in our communities.” Chelsea Johansen, Rainy Sunday Ranch, Photovoice 2017
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Chapter I Introduction
Since the early 1800s, agriculture has been a cornerstone county also provide food to consumers around the Puget of life in Snohomish County. Farms in the county have Sound region and beyond. produced milk, eggs, chickens, hogs, beef, berries, row crops, hay, nursery crops, and vegetables such as Despite the increasing importance and need for local corn, peas, and pumpkins.1 There are over 63,000 acres farming in Snohomish County, agriculture is threatened by of active farmland in Snohomish County.2 These acres development and by environmental changes. The United support 1,558 farms.2 While 85 percent of these farms States Department of Agriculture projected national farm are less than 50 acres, sizes vary and some farms are sector profits to decline by $9.8 billion from 2017 to 2018. as large as 2,000 acres.2 Agricultural products grown This represents 13 percent of the profits from farming. on these acres sell for over $157 million per year.2 Production expenses are forecast to increase by $11.8 Agriculture is an important component of the Snohomish billion due to increases in costs for fuel, feed, and hired County community, both socially and economically. In labor.4 Finances are just one of the pressures facing recent years, demand for local and sustainable produce farmers. American Farmland Trust has identified that 175 has increased at the same time as the population in acres of farm and ranch land in the United States are lost Snohomish County has gone up by almost 13 percent to sprawl and development every hour, while 1.7 billion from the 2010 Census, now reaching over 800,000 tons of topsoil are lost to erosion each year.5 These trends residents.3 As the population continues to increase, the and pressures also affect Snohomish County farms. need for locally grown food will also rise. Residents of Everett is one of the fastest growing cities in Washington Snohomish County buy local produce at the county’s State and the rising cost of land makes it difficult for seven farmers markets, through Community Supported farmers to stay in the county.6 Between 2012 and 2017, Agriculture (CSA) subscriptions, and at grocery stores like the acres of farmland in Snohomish County dropped from the Sno-Isle Food Co-op. Agricultural producers in the 70,863 to 63,671.2
“Agriculture is part of the social and environmental fabric of Snohomish County. It is emblematic of the enduring values of this community.… [F]armers are stewards of the land and are focused on the continued productivity of the land.”
Snohomish County. 2018. Snohomish County Agriculture Action Plan: A Plan to Preserve and Enhance the Agricultural Economy in Snohomish County. March 2005. https://snohomishcountywa.gov/DocumentCenter/View/8152/Snohomish-County-Agriculture-Ac- tion-Plan?bidId=
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In addition to the existing pressures on agriculture, climate change is expected to present additional challenges into the future. In Snohomish County, sea level rise is projected to lead to saltwater intrusion and rising Resilience groundwater tables. A changing climate is expected to Resilience is defined as the ability of something cause drier summers, wetter winters with more intense to withstand change or difficulties. Farmers have storms, increased river flooding, and impacts to crop honed this skill—constantly adapting to changes viability. The Puget Sound State of Knowledge: Climate in markets, regulations, and weather over the Change in Puget Sound report prepared by the University years. Now climate change has introduced new of Washington Climate Impacts Group describes difficulties. We have already experienced increased anticipated climate impacts at a regional scale. The report temperatures and higher intensity rainfall events. includes the following projections for Snohomish County These and other impacts are expected to continue under moderate greenhouse gas emission scenarios: into the future.
• The projected streamflow during a 100-year flood event is projected to increase up to 58 percent on the Snohomish River and 76 percent on the Stillaguamish The goals of the plan are to: River by the 2080s8 • Provide information and project funding for farmers to • The area inundated by a 10-year flood in the lower manage for future risk on their farms Snohomish River floodplain will increase anywhere from • Develop landscape-scale projects to improve 19 to 69 percent by the 2080s9 agricultural resilience • Protect agricultural lands from subdivision or • Spring peak flows in the Snohomish and Stillaguamish development rivers are projected to occur 29 to 49 days earlier than under current conditions by the 2080s8 The Agricultural Resilience Plan is linked to the work of the Snohomish County Sustainable Lands Strategy • The summer minimum streamflow will decrease by 7 to (SLS). SLS, started in 2010, is a collaborative effort 32 percent in the Stillaguamish River and by 17 to 33 of partners working to improve coordination and to percent in the Snohomish River by the 2080s8 generate progress for fish, farm, and flood interests in • The length of the growing season will increase, the Snohomish and Stillaguamish watersheds. The SLS but agriculture will also experience “shifts in crop effort is intended to lead to “a broad set of common production, increasing water supply challenges, understandings about the importance of fish and farms changing risks from pests, increasing winter flood risk, and the need for collaboration to simultaneously protect and an increasing risk of saltwater intrusion.”7 and enhance both resources while also recognizing and upholding Native American tribes’ treaty rights and This Agriculture Resilience Plan is intended to help cultural traditions.”10 SLS members are developing a prepare the agricultural community in Snohomish County series of reach-scale plans to identify coordinated sets for changes, whether from development, population of multiple-benefit projects to improve natural functions growth, erosion, shifts in weather, or climate change. within each reach while generating a net gain for farm, This is a plan that will help farmers in our county plan for fish, and flood interests.11 Reach-scale plans for the future challenges and risk, absorb future change, and Lower Skykomish River, Lower Snohomish River and more quickly recover from stress. The plan will help build Estuary, and Lower Stillaguamish River have been a resilient agricultural community into the future through completed and a plan for the North Fork Stillaguamish a combination of information gathering and sharing, River is underway. creation of online planning tools, project implementation, and farmland protection.
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As a participant in SLS, the Snohomish Conservation • Chapter III – Farmland Conservation describes the District identified a gap in the scientific understanding of Snohomish County Farmland Conservation Strategy, agricultural needs, particularly as they relate to climate a collaborative effort to preserve farmland and reduce change, as well as an organized planning approach to conversion and subdivision of farms. developing priority landscape-scale agricultural viability • Chapter IV – Resilience Practices describes practices projects. SLS participants representing fish interests farmers can adopt on their farm to plan for and increase are guided in their efforts by numerous plans and resilience to droughts and floods. studies, including the Snohomish River Basin Salmon Conservation Plan and the Stillaguamish Watershed • Chapter V – Impacts Assessment describes current Chinook Salmon Recovery Plan. Meanwhile, the and future impacts to agriculture, including climate agricultural representatives are farmers that don’t have change impacts to crops and the results of flooding, the benefit of completed plans and studies identifying groundwater, saltwater intrusion, and land subsidence landscape-scale needs or future impacts. Farmers also assessments. don’t have the staffing capacity to coordinate at the same level as other participants in SLS. This Agriculture • Chapter VI – Priority Needs identifies the most Resilience Plan is intended to fill this data gap and identify important actions needed to create a resilient priority resilience projects that will keep Snohomish agricultural system in Snohomish County. County’s agricultural lands viable into the future. • Chapter VII – Reach Summaries includes descriptions of 11 agricultural reaches in the Snohomish and This plan includes eight chapters: Stillaguamish River floodplains, including information on current and future impacts to agriculture and resilience • Chapter I – Introduction discusses the importance of needs. agriculture in Snohomish County and the purpose of the Agriculture Resilience Plan. • Chapter VIII – Next Steps describes how the Agriculture Resilience Plan will be implemented. • Chapter II – Outreach and Engagement describes how the Agriculture Resilience Plan has been guided by a Steering Committee of farmers and how input has been solicited from local farmers through community meetings and the PhotoVoice project.
The Farmer Does It All “On many small farms the farmer does it all—both in the field and the office. It can be overwhelming and challenging, but also rewarding. We market to various outlets— farmers markets, CSA, and wholesale. Each requires time, energy, and paperwork. We need an outlet we can count on that would bring more farms to Snohomish County. This could be a specific vegetable or fruit processor or a USDA meat processor.” Anna Caruso, Caruso Farm, Photovoice 2017
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1 Snohomish County, 2016. Snohomish County Comprehensive Plan. Land Use Chapter. Amended November 10, 2016.
2 United States Department of Agriculture, 2017. Table 8. Farms, Land in Farms, Value of Land and Buildings, and Land Use: 2017 and 2012. https://www.nass.usda.gov/Publications/AgCensus/2017/Full_Report/Volume_1,_Chapter_2_County_Level/Washington/st53_2_0008_0008.pdf
3 Office of Financial Management, April 1, 2018 Population of Cities, Towns and Counties Used for Allocation of Selected State Revenues.
4 United States Department of Agriculture, 2018. Highlights from the August 2018 Farm Income Forecast. https://www.ers.usda.gov/topics/ farm-economy/farm-sector-income-finances/highlights-from-the-farm-income-forecast/
5 American Farmland Trust, 2018. No Farms, No Food. https://www.farmland.org/no-farms-no-food?utm_medium=email&utm_source=govdelivery
6 Catchpole, D., 2017. Everett was the 9th fastest growing city in the state last year. Everett Herald. https://www.heraldnet.com/news/everett-was- the-9th-fastest-growing-city-in-the-state-last-year/
7 Mauger, G.S., J.H. Casola, H.A. Morgan, R.L. Strauch, B. Jones, B. Curry, T.M. Busch Isaksen, L. Whitely Binder, M.B. Krosby, and A.K. Snover, 2015. State of Knowledge: Climate Change in Puget Sound. Report prepared for the Puget Sound Partnership and the National Oceanic and Atmospheric Administration. Climate Impacts Group, University of Washington, Seattle. doi:10.7915/CIG93777D
8 Hamlet, A.F. et al., 2013. An overview of the Columbia Basin Climate Change Scenarios Project: Approach, methods, and summary of key results. Atmosphere-Ocean, 51(4), 392-415, doi: 10.1080/07055900.2013.81955.
9 Mauger, G.S., & Lee, S.-Y., 2014. Climate Change, Sea Level Rise, and Flooding in the Lower Snohomish River Basin. Report prepared for the Nature Conservancy. Climate Impacts Group, University of Washington, Seattle.
10 Snohomish County. Sustainable Lands Strategy website. https://snohomishcountywa.gov/2194/36450/Sustainable-Lands-Strategy
11 Snohomish County, 2018. Lower Skykomish River Reach-scale Plan, July 2017. https://snohomishcountywa.gov/DocumentCenter/View/45061/ Lower-Skykomish-Reach-Scale-Plan?bidId=
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Chapter II Outreach and Engagement
The Agriculture Resilience Plan is intended to be the farmers’ plan – a document that reflects the interests and priorities of farmers in Snohomish County. Therefore, outreach to and engagement with the farming community has been a key component of Steering Committee Members developing this plan and will continue to be central to Brian Bookey, Cherry Lane Farms its implementation. Input has been solicited through the formation of a Steering Committee of local farmers, Libby Reed, Orange Star Farm and outreach to existing agricultural groups and individual SCD Board Member farmers, and the PhotoVoice project. The next phase Jeff Ellingsen, SCD Board Member and Farmer of plan implementation will involve robust planning conversations with groups of farmers on the landscape Nick Pate, Raising Cane Ranch to develop and scope landscape-scale projects that Dan Bartelheimer, Sno Valley Farms improve agricultural viability. Jeremy Visser, dairy farmer Snohomish Conservation District formed a Steering Committee for the Agriculture Resilience Plan in order Darren Carleton, Carleton Farms to ensure that the plan is guided by the input of local Spencer Fuentes, Hazel Blue Acres farmers. The Committee is comprised of 9 Snohomish County farmers representing various types, sizes, and Andrew Albert, Andrew’s Hay locations of farms. The Steering Committee meets quarterly and provides guidance to the direction and development of the plan and its implementation. The Committee reviewed the technical information gathered as part of the Impacts Assessment (Chapter V) and fall 2016 and winter 2017, the Conservation District assisted in prioritizing the needs of agriculture at the reached out to existing agricultural groups to ask for county-wide scale. input into the scope of this project. Groups included the Snohomish Conservation District Board of Supervisors, In addition to soliciting guidance from the Steering Focus on Farming attendees, the Sustainable Lands Committee, the Conservation District conducted Strategy Agriculture Caucus, the Snohomish County extensive outreach to the local farming community. In Farm Bureau, Snohomish County Cattlemen, the
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Where it Happens “Prominent in the center of the farm is the barn, which gives a refuge throughout the seasons for family and for visitors who come to pick or buy organic blueberries in this beautiful, peaceful setting.” Karen Wolden-Fuentes, Hazel Blue Acres Farm, Photovoice 2017
Snohomish County Agricultural Advisory Board, SnoValley to respond to two questions – “Why is agriculture Tilth, the Coordinated Diking Council, the Marshland important to our community?” and “What are the major Flood Control District, the French Slough Flood Control challenges facing agriculture?” Themes that emerged in District, and the Stillaguamish Flood Control District. the photographs included farmland protection, increasing resilience to climate change impacts, improving drainage In spring 2019, the Conservation District launched a in the face of increased flooding, and the importance broader community engagement effort, primarily of local and sustainable agriculture. The photographs focusing on commercial farmers in the river floodplains. and accompanying captions were the centerpiece of an Presentations were given for local diking, drainage, and exhibition event attended by farmers, elected officials, flood control districts and community meetings were and agency staff. The photos were presented to the organized outside of these areas. The goals of this effort Snohomish County Council and have become part of were to provide localized results from the risk modeling an exhibition that has been shown at venues and events and assessment work and gather feedback on resilience throughout the county. Photographs and captions from needs and potential projects. This information was used the PhotoVoice project are included throughout this Plan. to create Reach Summaries (Chapter VII) that were then reviewed and revised by the farming community in summer 2019. In total, eight community meetings or presentations were organized and over 75 farmers provided input into the final recommendations in the plan.
In order to increase engagement of farmers in development of the Agriculture Resilience Plan, the Snohomish Conservation District and The Nature Conservancy conducted a PhotoVoice project. Seven farms took part in the project and participated in a series of four photography workshops. Participants were taught photography skills, then each took photographs
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Chapter III Farmland Conservation
Across the United States, farmland is being lost to development and conversion to other land uses. American Farmland Trust (AFT) reports that 31 million acres of agricultural land nationally were lost to development between 1992 and 2012. Such losses are usually irreversible. AFT also reports that development disproportionately affects agricultural lands—more What is a than 70 percent of urban development takes place Conservation Easement? on agricultural land.1 These trends are reflected in Snohomish County as well. For example, the USDA Agricultural conservation easements are Census of Agriculture reported that land in farming in voluntary legal agreements that prevent any future development from occurring on a property Snohomish County shrank from 70,863 acres in 2012 to by extinguishing development rights. At the 63,671 acres in 2007.2 These numbers don’t represent time the easement is put in place, the farmer is the additional impact of losing larger farms to smaller, compensated for the value of the development often non-commercial, farming uses. Pressures on the rights. Easements allow for agriculture and agricultural land base are increasing as the population of agricultural accessory uses as well as compatible the county rises—Everett is among the fastest growing activities such as habitat restoration, recreation, cities in Washington State—a population that could be and education. Easements are powerful tools for: fed by locally grown food if it was available.3 • Protecting priority agricultural resource lands;
In order to protect our local farms, a group of partner • Protecting farms suited for long-term viability due organizations and stakeholders have created a to soils and access to water and markets; and collaborative approach to farmland conservation in Snohomish County. Led by PCC Farmland Trust, the • Assisting landowners with achieving their goals Snohomish Farmland Conservation Working Group of honoring a farm legacy while supporting also includes the Snohomish Conservation District, business investments or succession plans. Snohomish County, Forterra, The Nature Conservancy, and the Washington Department of Fish and Wildlife. These organizations are committed to the preservation of farmland for agriculture through increasing the number of voluntary transactions (easements and fee acquisitions)
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A key component of the Strategy is coordination. Strategic partnerships are instrumental in increasing the pace of farmland conservation in Snohomish County. The Working Group has agreed to establish regular and ongoing communication that allows them to organize outreach efforts to priority parcel landowners and to share timely opportunities with one another. This will encourage partners to identify who the most appropriate lead organization is for both landowner outreach and individual transactions. Coordination helps maximize limited resources and lessen duplication of efforts; reduce confusion and frustration within the farming community; increase the extent of outreach and focus more strategically; and provide a consistent message to achieve Farms to Condos multi-benefit efforts. “Snohomish county is beating its plowshares into condos. Once, our living came from the land. Now, we crowd into compact The Farmland Conservation Working Group participates developments, shop at big box stores and work in urban in multi-benefit planning, specifically the Sustainable environments. Arable land is disappearing.” Lands Strategy (SLS) effort. As many of Snohomish Bill Pierce, Soaring Swallow Farm, Photovoice 2017 County’s prime working lands and large available blocks of farmland are in lowlands and floodplains, the Working Group recognizes the need to work with partners in SLS on priority Snohomish County farmlands. In addition, the to develop a balanced multi-benefit approach to floodplain group is supported by organizations (including Ducks management. In areas of the floodplain where priorities Unlimited) and farmers (including members from the SLS overlap, the Working Group commits to working collabo- agriculture caucus) who are critical to implementation of ratively with other floodplain interests and landowners on the Farmland Conservation Strategy that was developed projects that protect the landowner’s future flexibility in by the Working Group. determining the best use of the land.
The purposes of the Strategy are to: The Strategy also includes priority mapping. PCC Farmland Trust, with input from local partners and farmers, • Develop a roadmap for farmland conservation that developed an analysis and accompanying map to identify supports an integrated multi-benefit landscape approach and prioritize farmland for conservation. A suitability • Provide priority information to efforts such as the analysis, or prioritization, ranks properties relative to one Snohomish Agriculture Resilience Plan and the another based on a set of criteria that includes metrics Sustainable Lands Strategy reach scale plans that describe the quality of farmland and proximate development threats. Both the criteria and resultant maps • Better coordinate the partners involved in farmland were reviewed and approved by farmers on the Steering conservation to maximize opportunities Committee for the Agriculture Resilience Plan with the expectation that this map would be a working document • Develop a landscape-scale funding strategy that is updated and re-prioritized with forthcoming • Create goals and metrics for the key agricultural areas in information on potential climate impacts to flooding, Snohomish County groundwater levels, and saltwater intrusion. The resulting GIS data and maps can be used as a decision support • Increase the rate of farmland protection tool to assist the Farmland Conservation Working Group in identifying farmland conservation opportunities and
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conducting community outreach throughout Snohomish County. Figure III-1 shows high priority agricultural areas identified in the priority mapping. Table III-1 shows the acreage of agriculture in Snohomish County in each Stillaguamish Valley priority tier for protection. Preservation Initiative Table III-1 . Farmland Prioritization Acreage The Stillaguamish Valley Protection Initiative (SVPI) is a focus area effort nested in the overall PRIORITY RESULTS ACREAGE Snohomish Farmland Conservation Strategy. The Very high 15,421 main focus of this initiative is to protect farmland High 25,453 and the benefits that the open space associated Medium 26,282 with farmland provides for local food production, Low 34,164 flood storage capacity, water infiltration, and wildlife habitat. The urgency of protecting these lands from Very low 6,832 development is a shared priority for both agriculture Total 108,152 and salmon recovery interests, particularly in the face of forecasted population growth in Snohomish The highest priority farmland for protection (ranked County. Partners in this initiative and the SLS Very High and High in the mapping effort) equals a total advocate for flexible easements in the valley of approximately 40,000 acres. In the short-term, the that prioritize agricultural use but also recognize Farmland Conservation Working Group has identified a the value of habitat restoration if conditions ten-year voluntary conservation goal of 15,000 acres. change such that farming is no longer viable or if Voluntary conservation includes purchase of agricultural restoration would create a greater public benefit. conservation easements or acquisition of the land from willing sellers with an accompanying conservation easement. This short-term acreage goal represents the highest priority lands identified as most suitable for current funding sources. It is important to note that • Private foundations . Foundations currently fund the 15,000-acre goal is a short-term goal and does groups that facilitate voluntary transactions but are not not represent the full amount of farmland conservation currently paying for easements. needed to ensure market stability, food security, and the • Local Transfer of Development Rights . While a maintenance of critical farming infrastructure. While these Snohomish County Transfer of Development Rights lands are suitable for current funding sources, it is not program exists, improvements that could make it more possible to fund the purchase of conservation easements successful include the adoption of additional receiving on this volume of land with current funding sources alone areas, reduction of the enrollment fee, and creation of a within a ten-year period. Achieving this goal will require bank. success in both leveraging current funding sources and in working with decision makers to create new sources of • Regional Transfer of Development Rights . A regional funding. program exists for Transfer of Development Rights to the South Lake Union area of Seattle. The program is Existing funding sources for farmland protection include set up to use King County credits first, but the majority the NRCS Agricultural Conservation Easement Program, of King County credits have been purchased. The the Washington Wildlife and Recreation Program, program could be used to purchase development rights Snohomish County Conservation Futures, Floodplains from Snohomish County farms. by Design, and the local Transfer of Development Rights program. Potential new funding sources include:
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• Bond . A bond could be passed to provide funding for protection of agricultural land. This approach has been used in King County.
• Real Estate Excise Tax 3 . This tax, which would require County Council and public vote, could raise up to $41 million per year through property sales.
• Conservation Futures . The rate for this local tax could be increased by the County Council.
“You never forget visiting a farm. Whether it’s picking fruit, selecting a family pumpkin, or planting a tree. It’s honest work and it connects us with our core values and shared heritage.”
Nichlos Pate, Raising Cane Ranch, Photovoice 2017
1 American Farmland Trust, 2018. Farms Under Threat: The State of America’s Farmland. May 9, 2018. https://www.farmland.org/initiatives/ farms-under-threat
2 United States Department of Agriculture, 2012. Table 8. Farms, Land in Farms, Value of Land and Buildings, and Land Use: 2012 and 2007. https://www.nass.usda.gov/Publications/AgCensus/2012/Full_Report/Volume_1,_Chapter_2_County_Level/Washington/st53_2_008_008.pdf
3 Catchpole, D., 2017. Everett was the 9th fastest growing city in the state last year. Everett Herald. https://www.heraldnet.com/news/everett-was- the-9th-fastest-growing-city-in-the-state-last-year/
10 Prioritization criteria include factors related to land quality, threat of development, and federal and state funding criteria for farmland conservation and protection
Areas included in the analysis are:
• Assumed to be private, are not already protected or in forestry use • Greater than 10 acres in size • Aggregated adjacent areas where there is contiguous ownership • Have prime farmland soils covering a majority of the area (including those with restrictions or of statewide importance)
Conservation Approximate Priorities Acreage Very High (15,421ac.) High (25,453ac.) Medium (26,282ac.)
Please reference prioritization analysis report for detailed methods and assumptions. The underlying data can be symbolized in numerous ways and reside in a geodatabase for PCCFT collaborators to utilize with their permission.
Figure III-1 . Snohomish County Farmland Conservation Priorities
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Chapter IV Resilience Practices
Farmers are resilient; as a matter of course, farmers diversity, enhancing soil resiliency, and increasing adjust their practices from year to year based on land protections are some of the main strategies weather, soil conditions, and markets. Climate change recommended to address these three components of impacts, however, are expected to increase pressures on agricultural resilience. agriculture in Snohomish County and may necessitate added resilience measures or changes in management The practices and management approaches described altogether. Fortunately, there are a variety of tools and in this chapter do many things to help build resilience approaches that can be adopted to increase agricultural to climate change as well as to changing markets. They resilience. promote healthy soils by increasing organic matter content and therefore the soils’ ability to hold water Specific climate change impacts that are anticipated in during droughts. They build in diversification of products Snohomish County include less rainfall in summer months and revenue streams. They help protect livestock health and more (and higher intensity) rainfall in winter months, and production. They create alternative sources of water higher temperatures overall, decreased water availability, for livestock and irrigation. And they help protect farms increased flooding, heightened pest pressures, and the from pests, rising flood waters, and other changes we potential for saltwater intrusion into groundwater and expect to see in the coming years. irrigation ditches. Additional information on anticipated climate change impacts is included in Chapter V. These As part of the Agriculture Resilience Plan, the Snohomish impacts will put additional burden on Snohomish County Conservation District has developed a series of farms, which are already under threat from development factsheets on resilience practices that can be adopted and other pressures. by Snohomish County farmers. Resilience practices relate to cropping, livestock, soil, and water. When By their nature, agricultural activities are highly adopted successfully, the practices interact with each susceptible to the effects of environmental and social other and can most effectively derive benefits if applied changes. To stay productive and viable, agriculture in combination. The results of research on nine resilience requires the resilience to adapt to such changes. The practices are summarized in this chapter. Full factsheets Food and Agriculture Organization identifies three key on each resilience practice are available online at components of agricultural resilience: reducing exposure http://snohomishcd.org/ag-resilience/. The full factsheets to shocks (such as a pest outbreak or a flood), reducing go into detail about the effectiveness, implementation sensitivity to shocks, and increasing the ability to adapt. approach, and potential agricultural benefits of each Improving overall productivity, increasing product practice or set of practices.
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Silvopasture is the practice of incorporating trees into a livestock grazing system with the goal of integrating the management of tree crops, livestock, and forage. Trees are typically selected for their crop value and can include fruit, timber, or nut trees. Trees grow faster and wider in girth in a silvopasture system due to the fertilizer provided by animal manure. Forage stays productive longer into the season and has a better nutritional profile. Livestock show less overall stress, put on weight more easily, and produce more milk than livestock grazed in open pasture alone. Silvopasture offers a multifunctional land use in which production and protection can be achieved on the same parcel of land at the same time.
Agroforestry is a land management system that combines the production of perennial and annual crops with trees. Agroforestry maximizes economic production by producing high value tree crops while maintaining regular income with annual companion crops. Agroforestry practices include alley cropping, forest farming, riparian buffers, silvopasture, and windbreaks. These practices can be used individually or can be combined to create landscape-wide diversity of production and ecological benefit. Benefits of agroforestry can include positive impacts on soil ecology and water Viability holding capacity, decreases in weed competition, “Agricultural viability requires being open to new ideas.” increases in farm economic resiliency, access to new and potentially lucrative markets, protection of genetic Nichlos Pate, Raising Cane Ranch, Photovoice 2017 diversity in food crops, improvements to water quality, and decreases in erosion.
Managed grazing is a system that imitates the natural Biochar is a soil amendment with the potential to grazing patterns of large herbivores in savannah and improve soil tilth, enhance fertility, and decrease fertilizer prairie environments and eliminates overgrazing, a inputs and irrigation needs. Biochar, which is essentially problem worldwide and in Snohomish County. Animals charcoal, has traditionally been produced by piling in a managed grazing system can create landscapes wood, covering it with earth, and allowing it to burn in that are highly productive while protecting water quality, smoldering piles. This approach, however, releases a sequestering carbon, and creating and maintaining large amount of carbon into the atmosphere. A new, more carbon-rich soils. A managed grazing system focuses on efficient method has been developed; known as pyrolysis, two key components: how long livestock graze a specific this method involves heating organic materials in low area and how long the land is able to rest before livestock oxygen conditions. When added to soil, biochar can return. Benefits of managed grazing include increased increase soil health and water holding capacity, decrease production of forage, increased soil fertility, reduced fertilizer and irrigation needs, reduce soil acidity, absorb soil compaction, increased resistance to drought, better greenhouse gases, and enhance crop yields. control of forage species, cost savings, and carbon sequestration.
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Conservation Agriculture is a farming system that agroforestry, multi-species cover crops, and crop improves soil resilience and agricultural productivity rotations. Regenerative agriculture creates a system that through a set of soil management practices designed to more closely mimics nature’s ability to cycle nutrients and create an ongoing sustainable system. The three core eventually reduces the need for costly external resources principles of conservation agriculture are to minimize soil such as fertilizers and pesticides. This results in increased disturbance through no-till or conservation-till methods, yields, increased resilience to droughts and floods, and to maintain soil cover throughout the year with cover diversification of products. crops, and to manage crop rotations to combat pests and pathogens. No-till or conservation-till methods protect soil Integrated pest management is an ecosystem-based structure, soil composition, and biodiversity. Soil cover approach that aims to keep pest populations below the methods such as cover crops provide organic matter economic injury level while reducing the use of pesticides to feed the soil, protect against soil erosion by holding and minimizing risks to people and the environment. soil in place, and increase soil biodiversity and nutrient Specific techniques used in integrated pest management availability to crops. Crop rotations protect against pest can involve cultural controls, biological controls, and/ and disease problems by interrupting the life cycle of or mechanical controls. Cultural controls are practices certain bacteria, fungi, insects, and weeds. Conservation that reduce the initial establishment, reproduction, and agriculture produces a constant net increase of soil overall survival of a pest by creating a less hospitable organic matter rather than a decrease. At the same time, environment. Biological controls use a pest’s natural it produces a consistent improvement in soil moisture enemies (such as parasites, predators, or pathogens) to retention, which can minimize the impact of drought. keep pest populations low. This can be accomplished by increasing habitat for desirable species or through timed Regenerative agriculture is a method of farming the release of specific predators or pathogens. Mechanical land while at the same time regenerating or improving the controls directly kill, block, or make the environment natural functions of the farm ecosystem. Regenerative inhospitable to pests using physical components, such as agriculture involves adoption of a number of resilience temperature, humidity, or light. Examples of mechanical practices as part of a holistic system. These practices controls include tillage, flaming (burning an area), barriers can include no-till and pasture cropping, application of (such as fine mesh), soil solarization, and plastic mulching compost and/or biochar, managed grazing, silvopasture, for weeds.
Resilience “Climate change in this region has brought early floods and late floods, drought and, most recently, the highest spring rainfall in recorded history. As farmers we take note of these and other changes in the natural world because it’s part of our job. Our livelihoods are born of these natural processes (growing plants, raising livestock) and they are constantly in flux in small and large ways. It is humbling to work amidst the call and response of nature.”
Libby Reed, Orange Star Farm, Photovoice 2017
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Stormwater harvesting, also known as rainwater Waterbreaks are linear systems of forested plantings collection, is a method of storing rain that falls on roofs. planned and designed to reduce flooding impacts for Rainwater tends to have a neutral pH and is therefore lands adjacent to streams and rivers. Forested systems gentle on crops and can be stored for agricultural such as waterbreaks can help maintain some of the irrigation and watering. Harvesting rainwater from natural functions of a river system while reducing flood existing roofs is legal in Washington State, and property damages to agricultural lands. Waterbreaks can trap owners can have up to 5,000 gallons of storage volume and hold debris from floodwaters thus keeping it off of onsite without a permit. Permits can be obtained to agricultural fields. They also reduce scouring and sand store larger quantities of stormwater. Storage containers deposition in fields, protect levee systems, reduce soil include polyethylene tanks and PVC bladder tanks. and bank erosion, and protect water quality. Waterbreaks Typical systems require gutter work, tank installation, should be planted parallel to a river or stream as well as and a pumping system. A 1,000-square-foot roof in along field borders. Plant species used in waterbreaks Western Washington sheds over 22,000 gallons of water typically include native plants that can tolerate flood every year that could be stored and used for irrigation conditions and are adapted to the specific soils and site purposes. conditions.
1 Building Resilience for Adaptation to Climate Change in the Agricultural Sector: Proceedings of a Joint FAO/OECD Workshop. 23–24 April 2012. Edited by Alexandre Meybeck, Jussi Lankoski, Suzanne Redfern, Nadine Azzu and Vincent Gitz http://www.fao.org/docrep/017/i3084e/i3084e.pdf
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Chapter V Impacts Assessment
To understand the impacts of climate change on agricultural land in the Snohomish and Stillaguamish River floodplains, the Snohomish Conservation District initiated technical studies on flooding, groundwater levels, The Take-Away: Flooding saltwater intrusion, land subsidence and aggradation, and Increases in the extent of flooding will put crop impacts. This chapter summarizes key findings of additional farmland at risk of inundation, particularly these technical studies. The full studies and online tools during more frequent storm events (such as the can be found on the Conservation District website at 2-year and 10-year floods). Tens of thousands of https://snohomishcd.org/ag-resilience. additional acres will be flooded on a 2-year event by mid-century and critical stage heights will be exceeded more frequently each year. Flooding Much of the most valuable and productive farmland in Puget Sound is located within floodplains, which provide nutrient rich soils and excellent growing conditions. hazard conditions in the Stillaguamish and Snohomish While floodplains are important areas for agricultural River floodplains, the Conservation District partnered production, the flooding associated with these areas also with the University of Washington Climate Impacts Group poses a risk to agriculture. Flood waters and debris can (CIG) and Fathom to develop future flood hazard maps. damage structures, fencing and equipment resulting in CIG and Fathom used a regional flood frequency analysis costly repairs and clean-up efforts. High energy flows from historical records of river flows to develop hydraulic cause erosion to banks resulting in loss of land. High models, and then used future climate change projections waters pose a risk to livestock if not moved to higher for the 2050s and 2080s to develop flooding simulations. ground. In addition, the standing water and associated The approach used is a pilot of a new and less expensive drainage impacts can result in negative impacts to yields method of flood modeling. The resulting maps are at a and delayed spring cultivation. coarse scale (10m) and are thus most appropriate for general risk assessment and planning purposes, not for Climate change is expected to lead to more frequent and site-level analysis. severe flooding as sea levels rise and as precipitation patterns and loss of snowpack shift toward more intense winter storm events.1 In order to understand future flood
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Friend and Foe “Hazel Blue Acres is nestled snugly between stretches of the Stillaguamish River near Silvana, WA. Here, rows of organic blueberries weather the floods and droughts of life on that powerful and changeable river.” Karen Wolden-Fuentes, Hazel Blue Acres Farm, Photovoice 2017
Table V-1 . Projected Extent of Flooding
HISTORIC 2050s 2080s ACRES ACRES PERCENT CHANGE ACRES PERCENT CHANGE Stillaguamish River watershed 2-year flood 9,095 38,575 324% 41,448 356% 10-year flood 37,642 54,288 44% 56,988 51% 100-year flood 65,281 66,527 2% 68,267 5% Snohomish River watershed 2-year flood 16,946 40,134 137% 45,511 169% 10-year flood 64,392 72,330 12% 76,111 18% 100-year flood 93,995 94,276 <1% 98,228 5%
Projected increases in discharge and flood stage will from 16,946 acres to 40,134 acres. More severe changes increase the amount of land inundated in a flood. The are projected for the more frequent 2- and 10-year flood table above shows the acreage flooded and the percent events, while the 100-year event (1% chance) will see change in area flooded for both watersheds given historic smaller increases in the amount of land inundated. data (closest approximation of current conditions) as well as under projected flooding conditions for the 2050s and Modeled flood extents for specific locations can be the 2080s (RCP 8.5 high emissions scenario).2 viewed in an online web map that can be accessed from https://snohomishcd.org/ag-resilience. However, it is As shown in Table V-1, increases in the extent of flooding important to note that the model is at a coarse scale will put additional farmland at risk of inundation. In the and most appropriate for high-level risk assessment and Stillaguamish River watershed, current flooding extent for planning, not site-level analysis. the 2-year flood (50% chance event) is projected to more than quadruple by the middle of the century, going from Agricultural producers in the county have expressed 9,095 acres inundated to 38,575 acres. In the Snohomish that yearly flood frequency is as important as flood River watershed, projections indicate the acreage height when assessing the potential for future risk. CIG inundated in a 2-year flood will more than double, going completed an analysis looking at the change in number of
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Table V-2 . Projected Days Per Year Stage Thresholds are Exceeded
2050s 2080s STAGE HISTORIC RCP 4.5 – LOW RCP 8.5 – HIGH RCP 4.5 – LOW RCP 8.5 – HIGH (AVG) (AVG) (AVG) (AVG) Stillaguamish River 17 ft 1.2 2.9 3.0 3.5 3.5 at Arlington 19 ft 0.5 1.3 1.4 1.6 1.7 Snohomish River 17 ft 1.1 2.6 2.9 3.2 3.9 near Monroe 23 ft 0.2 0.4 0.4 0.5 0.7 days a year the rivers reach specific flood stages based on farmer input into key flood stage thresholds (e.g. when Groundwater Levels levees overtop, livestock must be evacuated, structures Groundwater levels are a major variable affecting flood, etc.). In the Stillaguamish River floodplain, farmers agricultural operations in the lower Snohomish and identified the 17-foot and 19-foot flood stages as critical, Stillaguamish River floodplains. The timing and extent of which correspond roughly to the 2- and 3-year events. groundwater saturation affects when farmers can get out In the Snohomish River floodplain, farmers identified the on their fields in the spring; accessing when fields are too 17-foot and 23-foot stages, which correspond roughly to wet can cause damage to equipment and soils. Wetter the 3- and 13-year flood events. years will result in delayed access to fields and drier years may allow earlier access depending on crop types. In the Table V-2 shows the average number of days per year fall, rain and the associated rise in the groundwater table these stage thresholds are exceeded using historic data effectively ends the cultivation season. alongside projections for the 2050s and the 2080s at the Stillaguamish River at Arlington gauge (#34) and Climate change is expected to impact groundwater 3 the Snohomish River near Monroe gauge (#12150800). conditions and timing in both watersheds. A rise in Average estimates are shown here for two climate relative sea level is expected to raise groundwater levels projection scenarios (low or high greenhouse gas and extend the period of saturation in the spring, thereby emissions). The modeling indicates increases in flood delaying field access. The impact of sea level rise on frequency of all stage heights by the 2050s and again groundwater levels may also shorten the agricultural for the 2080s. For example, the models show that the season in the fall as groundwater levels return to 17-foot stage on both rivers is exceeded for 3 days per pre-spring conditions earlier. year, on average, by the 2050s, whereas historically it has only been exceeded about one day per year, on average. Table V-3 shows relative sea level rise projections at the The more extreme stages on both rivers – 19-foot on the Snohomish River and Stillaguamish River mouths (RCP Stillaguamish and 23-foot for the Snohomish – also occur 8.5 high emissions scenario). more frequently in the future, happening about two to three times as often by the 2050s and three to four times Table V-3 . Relative Sea Level Rise Projections as often by the 2080s. YEAR YEAR YEAR 2050 2080 2100 Snohomish 0.8 feet 1.5 feet 2.2 feet River Stillaguamish 0.7 feet 1.5 feet 2.2 feet River 4
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To better understand the impacts of sea level rise on groundwater, the Conservation District hired Cardno to assess the impact of rising sea levels on groundwater levels in the spring and fall on floodplain agricultural The Take-Away: Groundwater 3 land. The study examined the lower Snohomish and Rising sea levels are anticipated to delay the time Stillaguamish basin floodplains from the mouth upstream when farmers can access their fields in the spring to the extent of tidal influence on groundwater levels for by up to four weeks by the 2050s and up to five each river system. For the Snohomish River, the study weeks by the 2080s. area extended from the mouth of Possession Sound to Thomas’ Eddy at river mile 16.1. The Stillaguamish River study area extended from the mouth of the river at Hatt Slough upstream to the Pioneer Highway Bridge at river mile 7.4. waters. Figures V-1 through V-4 at the end of this chapter show 2050 and 2100 groundwater projections for both In order to confirm assumptions about geology and to the Snohomish and Stillaguamish watersheds. document groundwater levels across seasons, Cardno installed wells throughout the study areas. They also used The study found that the effects of sea level rise on the data from existing wells operated by Snohomish County, timing of groundwater conditions in the fall are not likely the Stillaguamish Tribe, and the Washington Department to be significant because anticipated changes in levels of Fish and Wildlife. Cardno used the recently released would be within the range already experienced under Projected Sea Level Rise for Washington State – A 2018 natural tidal cycles. Therefore, the delay in start times for Assessment4 to incorporate projections of relative sea working fields in the spring would not be made up in the level rise into the analysis. Sea level rise was assumed fall. to affect river channels up to the current extent of tidal influence. A separate analysis was conducted for Ebey Island in the Lower Snohomish River floodplain. Because no Examination of existing groundwater conditions showed groundwater data is available for Ebey Island, well data that groundwater at farms in both the Snohomish and from nearby Smith Island was used as an analog. It was Stillaguamish watersheds tend to decline about one foot found that groundwater levels on Smith Island track the per month through the spring. In the fall, higher river flows levels of Puget Sound tides and are within a foot of the cause groundwater levels to increase to early-spring height of the adjacent slough during summer months. If elevations. Based on this information about current we apply this relationship to Ebey Island, it indicates that conditions, the groundwater study was able to project sea level rise could have a direct impact on groundwater delays in spring cultivation by calculating how long it levels. The analysis shows that a number of areas on would take future groundwater levels, raised by sea level the island would lie below the groundwater table and rise, to fall to current spring conditions. be inundated without active drainage and pumping (see Figure V-5 at the end of this chapter). However, farmers Results indicate that rising sea levels are anticipated to on Ebey Island have stated that pumping and drainage delay the time when farmers access their fields in the effectively dry out all cultivated areas. This emphasizes spring. While natural variation will continue, sea level rise the critical role pumping plays in maintaining agricultural will generally increase the delay of start times for working viability, a role that will become even more important with fields and this increase will become more and more sea level rise. pronounced with time. For low-lying farmland, delays could reach three weeks by the 2050’s and four to five weeks by the 2080s. Areas closer to the Puget Sound coast (within a few miles) will feel the greatest effects of this change because of their proximity to rising marine
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Saltwater Intrusion Agricultural areas located near marine waters can suffer from saltwater intrusion, which occurs when The Take-Away: saline waters move into groundwater aquifers. In the Saltwater Intrusion Lower Stillaguamish and Snohomish River floodplains, On Florence Island in the Lower Stillaguamish, groundwater with increased salinity due to saltwater patches of farmland already experience saltwater intrusion could affect the growing conditions for crops if intrusion above crop tolerance thresholds, and that salinity reaches root zones. Though salts are crucial those impacts are likely to increase in severity over plant nutrients, high concentrations of any one salt or the next 50 years. many different salts can be toxic to plants. Sea level rise Areas closest to the shoreline are at the highest risk could increase saltwater intrusion into groundwater in of saltwater intrusion. Areas within 5,000 feet of the these areas as the saltwater interface rises in relation to shoreline are especially vulnerable, and areas within freshwater aquifers. 10,000 feet could also experience increases over time. In addition to analyzing groundwater levels and ponding, the aforementioned groundwater study completed by Increasing pumping on Florence Island is not Cardno also assessed the effect of sea level rise on recommended unless additional groundwater analysis negates the finding of this study, as saltwater intrusion into shallow groundwater. Cardno pumping could result in increasing the amount of measured salinity levels in the wells drilled for the agricultural land impacted by salinity. groundwater level study, as well as analyzed data from partner’s wells. Salinity impacts are measured in millisiemens per centimeter (mS/cm), a metric that measures conductivity values as a surrogate to salinity. Based on the salt tolerance of crops most commonly end of this chapter shows the late spring/early summer grown in the Lower Stillaguamish and Snohomish River salinity threshold in the Stillaguamish estuary currently, floodplains (corn, grass, beets, spinach, and cabbage) as well as predictions for where the salinity impact will and the depth of the wells used in the study, it was expand to in the future. assumed that 3 mS/cm would best indicate potential impacts of saltwater intrusion on agricultural production. Geographic location is a key factor in saltwater intrusion The response of plants to 0-2 mS/cm is mostly negligible, impacts. Areas closest to the shoreline have the highest while sensitive plants can experience yield impacts with risk of increased groundwater salinity intrusion due to 2-4 mS/cm. Most plants would be restricted by 4-8 mS/ rising sea levels. Areas within 5,000 feet of the shoreline cm, and only tolerant plants can grow under conditions are especially vulnerable to groundwater salinity intrusion with 8 mS/cm or more. to the shallow rooting zone of crops but areas within 10,000 feet may also experience measurable increases In the Lower Stillaguamish, existing conductivity over time. To a high level of certainty, Florence Island measurements at wells within 1,000 feet of Hatt Slough (near the mouth of the Stillaguamish River) already showed a range of 0.1 to 6.7 mS/cm in late August 2016. experiences salinity above crop tolerance thresholds, and These readings suggest that crops in the lower estuary those impacts are likely to increase in severity over the may already be stressed by existing salinity conditions. next 50 years. In contrast, agricultural land on Ebey Island Farmers in this area confirm that this is true in patches, in the Snohomish River floodplain may not experience but that most land is still highly productive. Data suggests significant increases in salinity intrusion to shallow that rising sea levels of one foot will increase conductivity groundwater due to its location further from marine measurements by approximately 1 mS/cm in the waters. Because the Marshland and French Slough groundwater of farms near the coast. Figure V-6 at the Flood Control Districts are greater than 20,000 feet from
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the marine boundary, sea level rise is not expected to cause significant increases in salinity intrusion to shallow groundwater. The Take-Away: Subsidence Traditional pumping and infrastructure solutions to and Aggradation rising seas may not provide adequate protection for the The analysis of subsidence for both the future. For example, installation of pumps to reduce Stillaguamish and the Snohomish floodplains groundwater impacts to drainage could draw deep, salty showed little direct evidence for regional groundwater upward, closer to the rooting zone of crops. subsidence, and limits the calculation of localized Future improvements to pumps and drainage systems subsidence to no more than 2.4 inches per decade must consider groundwater salinity intrusion effects from if it is occurring at all. rising sea levels. In the Snohomish River, pumping in the The Stillaguamish River channel is aggrading near Marshland and French Slough Diking Districts is not likely the mouth, and this trend is likely to continue to impact groundwater salinity, but additional analysis is into the future. The Lower Snohomish River is recommended before implementing a more aggressive not aggrading, but upper reaches (from the SR-9 pumping approach further downstream on Ebey Island. Bridge to the Skykomish) show some aggradation. In the Stillaguamish River, increasing the amount of pumping on Florence Island is not recommended unless additional groundwater analysis negates the finding of this study, as pumping could result in increasing impact of salinity on agricultural land. river channel and subsidence of adjacent farmland can increase the flood and drainage impacts to some The interplay of sea level rise, groundwater, and surface agricultural areas. water management for the lower Stillaguamish and Snohomish River floodplains is complex and many In order to study whether land subsidence and uncertainties remain that have not yet been resolved. The aggradation is affecting agriculture in the Snohomish study recommends a focused data collection effort to and Stillaguamish River floodplains, the Conservation evaluate the degree to which salinity already affects crop District contracted Cardno to conduct subsidence and yields in the region. aggradation studies for each watershed. To evaluate subsidence, Cardno re-surveyed elevations in areas that have been surveyed in the past, including monuments and benchmarks, roads, agricultural lands, and levees. Land Subsidence and The study also involved analysis of the vertical difference Channel Aggradation between elevations from multiple LiDAR datasets. To evaluate aggradation, Cardno compared recent Subsidence refers to the downward sinking of the channel cross-sections to historical surveys, evaluating ground surface. Subsidence of agricultural lands can 48 cross-sections of the Stillaguamish River and its occur from the lack of sediment inputs to the floodplain, tributaries and 19 cross-sections of the Snohomish River. soil compaction, groundwater withdrawals, and decomposition of soil organics. Aggradation refers to the The analysis of subsidence5 in the Stillaguamish rising of the ground surface and, in this study, refers to floodplain was inconclusive. The accuracy of LiDAR data the accumulation of sediment within the river channel. comparisons was suspected to be influenced by varying Aggradation can increase the risk of flooding because it heights of vegetation, making accurate conclusions decreases the capacity of the river to carry flood volumes. difficult. The resurvey of benchmarks suggests localized Subsidence contributes to drainage issues in agricultural subsidence in known locations, but does not provide an fields and can increase the risk of levee failure through indication of larger-scale agricultural land subsidence. settling and shifting. Therefore, aggradation within the In general, the data shows little direct evidence for
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regional subsidence and limits the magnitude of localized to 2011.5 The general trend of aggradation is expected subsidence to no more than 2.4 inches per decade in to continue into the future. Dredging in the Lower some areas. The study concludes that the impact of sea Stillaguamish River is not considered to be an option for level rise on groundwater levels and salinity as well as the mitigating this risk because it would not reduce future impact of larger winter flood events should be a greater sediment inputs that would continue to aggrade the river concern than subsidence. and because it would only cause a negligible decrease in the peak flood stage. Potential subsidence in the Snohomish River floodplain was also assessed using LiDAR data as well as re-survey Analysis of the Lower Snohomish River showed that the of benchmarks. This analysis showed a range of river channel has remained stable from year to year and subsidence from 1 to 6 inches approximately every 10 has not aggraded.6 However, the upper reach of the river years in some areas.6 In general, however, the uncertainty (from the SR-9 Bridge to the confluence of the Skykomish in the LiDAR comparisons exceed the magnitude of and Snohomish Rivers) showed aggradation. This reach elevation change that may have occurred, so the datasets may experience modest aggradation into the future. are not conclusive. Similar to the Stillaguamish River, the data limits the likely magnitude of subsidence to no more than 2.4 inches per decade, and primarily in areas with Crops high organic soils on Ebey Island and in the Marshland The State of the Knowledge: Climate Change in Puget and French Slough Flood Control Districts. Local farmers Sound reports that the impacts of climate change on local indicate that organic soils subside more quickly in the agriculture include increased temperatures, changes in years after initial clearing, draining and cultivation than in seasonal precipitation and a lengthening of the growing subsequent years. season, all of which may positively or negatively impact 1 In the Stillaguamish River, cross-sections of the river specific agricultural products or farmland. Washington channel showed that both the main channel and the State University’s Center for Sustaining Agriculture Old Main Channel experienced aggradation from 1997 and Natural Resources developed an online Climate Visualization Tool that allows farmers to visualize
Climate Change “Seeds are planted and sprout undercover and we, as farmers, wait for the rain to stop and fields to dry out enough to do soil work and prepare beds for getting all of these plants in the ground. This past spring was similar to ones in the past, only the rains didn’t let up in April as they normally do. While a little extra rain might be a small inconvenience to some, this kind of climatic event makes a very real impact on farmers and food production. Most farmers are 4-6 weeks behind schedule because of delays brought on by abnormal rainfalls, but nature itself is also behind. Asparagus, a perennial crop, was also weeks late in coming up this year. What will next Spring bring? How much added resilience is necessary to withstand these changes?” Libby Reed, Orange Star Farm, Photovoice 2017
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projected climate changes as they relate specifically to agricultural crops in the Pacific Northwest. The tool shows crops grown in 6 km x 6 km grids across the landscape and provides projections to the years 2040, The Take-Away: Crop impacts 2060 and 2080 for impacts associated with: Increasing air temperatures in summer months are projected to negatively impact some existing crops • Temperature while at the same time providing opportunities for • Growing degree day accumulation new types of agricultural production. This warming • Growing season length will result in a longer growing season but also an • Precipitation accelerated growing degree day accumulation, • Climate analogues which can have a negative impact on yields. Models project a decrease in summer precipitation The tool can be found at and an increase in winter precipitation. http://agclimatetools.cahnrs.wsu.edu/cbcct/. By the 2040s, Snohomish County is predicted Below is a summary of the projected impacts of to have similar growing conditions to Santa Cruz climate change on temperature, growing season, and County, CA, just south of San Jose. And by the precipitation as they relate to future crop viability in 2080s, conditions are expected to be most similar to Santa Barbara County, CA, just north of Los Snohomish County. Angeles.
TEMPERATURE Increasing air temperatures in summer months are projected to negatively impact some existing crops while at the same time provide opportunities for new types GROWING DEGREE DAYS of agricultural production. The agricultural areas in the Warming can result in accelerated growing degree day lowlands of the Puget Sound region have warmed 1.3°F accumulation, which can lead to earlier maturity and in the last 120 years with nighttime temperature rising decreases in yields for some crops or more time under faster than daytime temperature.1 In Snohomish County, optimal conditions resulting in yield increases for other climate models consistently project continued warming crops.8 Growing degree days are the plant’s calendar, in the lowlands, although the magnitude of change can determining its phenology or timing of growth stages. It is vary by model. Depending on the emissions scenario a measurement of heat accumulation based on minimum used (low or high greenhouse gas emissions), average and maximum daily temperatures and crop-specific projected increases in annual average temperatures are optimal high and low temperature thresholds. Overall 4.0°F - 5.5°F by midcentury and 5.5°F - 8.5°F by the end yield impacts are very crop- and location-specific and of the century. Projections also indicate that we will see depend of the relative balance between temperature an increase in extreme heat events, while the frequency effects which can be positive or negative and a carbon of extreme cold events will decrease.1 In addition to the dioxide fertilization effect which is generally positive.8 potentially positive or negative impacts to growing degree day accumulation described below, warming related risks The maturity of annual crops such as corn, barley, and include exposure to heat stress events and insufficient potatoes in Snohomish County is projected to advance chill accumulation before bloom for perennial trees.7 by about a month by midcentury, and by a couple of months by end of the century. This will open up new opportunities, including the potential to double crop if there is sufficient water availability as well as the potential to access new markets via crops that become suitable under these new conditions.9,10
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GROWING SEASON LENGTH CLIMATE ANALOGUES The growing season length, defined as the number of Researchers at WSU conducted an analysis of crop frost free days (number of days between the last frost growing condition analogues that can help farmers plan in spring and the first frost in fall), is also predicted to for future conditions.12 Using soil and climate data for the increase.11 While the current growing season length Western U.S., this analysis answers the question “is there in Snohomish County is approximately 260 days, another county whose current growing conditions are projections show approximate lengthening of the growing similar to what is predicted for Snohomish County?” This season of 75 days by midcentury and 100 days by the information is shown by county for Washington, Oregon, end of the century. This measurement of the growing and Idaho using the Climate Visualization Tool linked season length does not take into account other factors above. influencing the ability to grow crops such as groundwater levels and the availability of light during winter months. By the 2040s, Snohomish County is predicted to have similar growing conditions to Santa Cruz County, CA, just south of San Jose. And by the 2080s, conditions are PRECIPITATION expected to be most similar to Santa Barbara County, Natural variability in annual precipitation is high, making CA, just north of Los Angeles. Information such as the future projections highly variable. Models consistently types of crops, management practices, and pest control indicate, however, a projected decrease in summer in analogue counties can provide valuable information precipitation under all greenhouse gas emissions to Snohomish County farmers wanting to plan for and scenarios. Most models predict a decline in summer manage risk into the future. precipitation of 22%, on average, by the 2050s.1
While winter, spring, and fall precipitation projections show only modest increases (2 – 11% on average) by mid-century, precipitation extremes are projected to increase and occur more frequently. As temperatures increase, models predict that rain will be the dominant form of precipitation in most watersheds in the Puget Sound by the end of the century – watersheds such as the Snohomish River that have historically been highly influenced by snowfall.1 These shifts in the hydrologic cycle will mean more flooding in winter months and lower stream flows in summer months.
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26 Spring Crop 5 !( Cultivation Delay High5 Week : 5 Delay
3 Week Delay
!(6
1 Week Delay SLR Delay to Spring Crop Cultivation ...... 7 !( Snohomish Year 2050 RCP 8.5 (High Emissions) 8 !( ...... Prepared For: Snohomish Conservation District Snohomish County, WA
Legend
!(9 !( River Mile
!(10 *# Cardno Well MW2 Golden Eagle North 11 *# !( Top
State Highway
!(12 Analysis Extent 13 Marshland FCD !( Flood Control District (FCD) *# MW3 Grasslands *# MW1 Golden Eagle South
!(14
Prepared By Cardno August 2018 French Slough FCD
15 !( 801 Second Avenue Suite 700 Phone # Seattle, WA 98104 (206) 269-0104 www.cardno.com
NAD83 WA State Plane, North
MW4 Craven Farm *# Service Layer Credits: Sources: Esri, HERE, DeLorme, 16 USGS, Intermap, INCREMENT P, NRCan, Esri Japan, !( METI, Esri China (Hong Kong), Esri Korea, Esri ± (Thailand), MapmyIndia, NGCC, © OpenStreetMap contributors, and the GIS User Community 00.25 0.5 1 1.5 2 Source: Esri, DigitalGlobe, GeoEye, Earthstar Miles Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community
!(
Figure V-1 . SLR Delay to Spring Crop Cultivation, Snohomish Floodplain, Year 2050 . This figure shows the projected delay to spring crop cultivation due to changes in groundwater levels. The projection is shown for the year 2050 using RCP 8.5 scenario (high emissions).
27 Spring Crop 5 !( Cultivation Delay High5 Week : 5 Delay
3 Week Delay
!(6
1 Week Delay SLR Delay to Spring Crop Cultivation ...... 7 !( Snohomish Year 2100 RCP 8.5 (High Emissions) 8 !( ...... Prepared For: Snohomish Conservation District Snohomish County, WA
Legend
!(9 !( River Mile
!(10 *# Cardno Well MW2 Golden Eagle North 11 *# !( Top
State Highway
!(12 Analysis Extent 13 Marshland FCD !( Flood Control District (FCD) *# MW3 Grasslands *# MW1 Golden Eagle South
!(14
Prepared By Cardno August 2018 French Slough FCD
15 !( 801 Second Avenue Suite 700 Phone # Seattle, WA 98104 (206) 269-0104 www.cardno.com
NAD83 WA State Plane, North
MW4 Craven Farm *# Service Layer Credits: Sources: Esri, HERE, DeLorme, 16 USGS, Intermap, INCREMENT P, NRCan, Esri Japan, !( METI, Esri China (Hong Kong), Esri Korea, Esri ± (Thailand), MapmyIndia, NGCC, © OpenStreetMap contributors, and the GIS User Community 00.25 0.5 1 1.5 2 Source: Esri, DigitalGlobe, GeoEye, Earthstar Miles Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community
!(
Figure V-2 . SLR Delay to Spring Crop Cultivation, Snohomish Floodplain, Year 2100 . This figure shows the projected delay to spring crop cultivation due to changes in groundwater levels. The projection is shown for the year 2100 using an RCP 8.5 scenario (high emissions).
28 Spring Crop Cultivation Delay High5 Week : 5 Delay
!( 3 Week Delay
1 Week Delay SLR Delay to 1 !( Spring Crop Cultivation ...... 1 !( Year 2050 RCP 8.5 (High Emissions)
4 ...... !( Prepared For: !(2 Snohomish Conservation District
!(3 Snohomish County, WA
!(5
6 Legend !(0 !( MW6 Miller*# Road !( River Mile 7 !( Stillaguamish FCD *# Partner Well Top
7 *# Cardno Well Marine Drive Bridge !( 8 MW5 Schakel Top 2 !( *# !( *# Oberg 5 3 4 !( Analysis Extent !( !( Pioneer Hwy Bridge !(1
!(6 Flood Control 9 !(10 !( District (FCD) !(8 *# *# Nygaard B3 *# *# 0 !( B2 B1 !(11
Prepared By Cardno August 2018
801 Second Avenue Suite 700 Phone # Seattle, WA 98104 (206) 269-0104 www.cardno.com
NAD83 WA State Plane, North
Service Layer Credits: Sources: Esri, HERE, DeLorme, USGS, Intermap, INCREMENT P, NRCan, Esri Japan, METI, Esri China (Hong Kong), Esri Korea, Esri ± (Thailand), MapmyIndia, NGCC, © OpenStreetMap contributors, and the GIS User Community 00.25 0.5 1 1.5 2 Source: Esri, DigitalGlobe, GeoEye, Earthstar Miles Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community
Figure V-3 . SLR Delay to Spring Crop Cultivation, Stillaguamish Floodplain, Year 2050 . This figure shows the projected delay to spring crop cultivation due to changes in groundwater levels. The projection is shown for the year 2050 using an RCP 8.5 scenario (high emissions).
29 Spring Crop Cultivation Delay High5 Week : 5 Delay
!( 3 Week Delay
1 Week Delay SLR Delay to 1 !( Spring Crop Cultivation ...... 1 !( Year 2100 RCP 8.5 (High Emissions)
4 ...... !( Prepared For: !(2 Snohomish Conservation District
!(3 Snohomish County, WA
!(5
6 Legend !(0 !( MW6 Miller*# Road !( River Mile 7 !( Stillaguamish FCD *# Partner Well Top
7 *# Cardno Well Marine Drive Bridge !( 8 MW5 Schakel Top 2 !( *# !( *# Oberg 5 3 4 !( Analysis Extent !( !( Pioneer Hwy Bridge !(1
!(6 Flood Control 9 !(10 !( District (FCD) !(8 *# *# Nygaard B3 *# *# 0 !( B2 B1 !(11
Prepared By Cardno August 2018
801 Second Avenue Suite 700 Phone # Seattle, WA 98104 (206) 269-0104 www.cardno.com
NAD83 WA State Plane, North
Service Layer Credits: Sources: Esri, HERE, DeLorme, USGS, Intermap, INCREMENT P, NRCan, Esri Japan, METI, Esri China (Hong Kong), Esri Korea, Esri ± (Thailand), MapmyIndia, NGCC, © OpenStreetMap contributors, and the GIS User Community 00.25 0.5 1 1.5 2 Source: Esri, DigitalGlobe, GeoEye, Earthstar Miles Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community
Figure V-4 . SLR Delay to Spring Crop Cultivation, Stillaguamish Floodplain, Year 2100 . This figure shows the projected delay to spring crop cultivation due to changes in groundwater levels. The projection is shown for the year 2100 using an RCP 8.5 scenario (high emissions).
30 Figure V-5 . Projected Depth-to-Groundwater Map for Ebey Island and Vicinity . This figure shows the projected depth-to-groundwater map for Ebey Island under modern sea level and assuming no pumping. The blue areas lie at elevations below the assumed groundwater table, and so are currently dependent on active drainage measures to remain dry. In general, the darker blue areas closely correspond to wet areas or boils that are readily observed on aerial photographs. 31 Figure V-6 . Future Conditions Depth-to-Groundwater Map for Ebey Island and Vicinity . This figure shows the projected depth-to-groundwater map for Ebey Island in 2080 under an RCP 8.5 (high emissions) scenario.
32 Figure V-7 . Early Summer Salinity Intrusion to Groundwater . This figure shows the projected level of salinity intrusion in the Stillaguamish Estuary out to 2100. The shaded lines represent where the threshold for crop impacts is expected to reach for that year.
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1 Mauger, G.S., J.H. Casola, H.A. Morgan, R.L. Strauch, B. Jones, B. Curry, T.M. Busch Isaksen, L. Whitely Binder, M.B. Krosby, and A.K. Snover, 2015. State of Knowledge: Climate Change in Puget Sound. Report prepared for the Puget Sound Partnership and the National Oceanic and Atmospheric Administration. Climate Impacts Group, University of Washington, Seattle. doi:10.7915/CIG93777D
2 Fathom, 2019. Puget Sound Hazard Mapping Report.
3 Cardno, 2019. Climate impacts to groundwater in the Lower Snohomish and Stillaguamish River basins. Report produced for the Snohomish Conservation District. Lake Stevens, WA.
4 Miller, I.M., H. Morgan, G. Mauger, T. Newton, R. Weldon, D. Schmidt, M. Welch, and E. Grossman, 2018. Project Sea Level Rise for Washington State – A 2018 Assessment. A collaboration of the Washington Sea Grant, University of Washington Climate Impacts Group, Oregon State University, University of Washington, and US Geological Survey, Prepared for the Washington Coastal Resilience Project.
5 Cardno, 2019. Technical Memo: Stillaguamish Flood Control District subsidence and sedimentation study. Report produced for the Stillaguamish Flood Control District. Lake Stevens, WA.
6 Cardno, 2019. Technical Memo: Lower Snohomish River district subsidence and sedimentation study. Report produced for the Snohomish Conservation District. Lake Stevens, WA.
7 Noorazar, H., L. Kalcsits, V.P. Jones and K. Rajagopalan. Tree-fruit production risks in the Pacific Northwest due to insufficient chill accumulation. Climatic Change (In preparation).
8 Rajagopalan K., K. Chinnayakanahalli, C. Stockle, R. Nelson, C. Kruger, M. Brady, K. Malek, S. Dinesh, M.E. Barber, G. Yorgey and J. Adam, 2018. Impacts of near-term regional climate change on agriculture in the Columbia River basin. Water Resources Research.
9 Barik, M., J.C. Adam, J. Yoder, M.P. Brady, D. Haller, M.E. Barber, Hall, S.A., C.E. Kruger, G.G. Yorgey, M. Downes, C.O. Stockle, B. Aryal, T. Carlson, G. Damiano, S. Dhungel, C. Einberger, K. Hamel-Reiken, M. Liu, K. Malek, S. McClure, R. Nelson, M. O’Brien, J. Padowski, K. Rajagopalan, Z. Rakib, B. Rushi, W. Valdez (2017), 2016, Technical Supplement for the Columbia River Basin Long-Term Water Supply and Demand Forecast. Publication No. 16-12-008. Washington Department of Ecology, Olympia, WA. 216 pp. Available online at: https://fortress.wa.gov/ecy/publications/ SummaryPages/1612008.html
10 Bisbis, M.B., Gruda, N. and Blanke, M., 2018. Potential impacts of climate change on vegetable production and product quality–A review. Journal of Cleaner Production, 170, pp.1602-1620.
11 Climate Visualization Tool (CVT) http://agclimatetools.cahnrs.wsu.edu/cbcct/. (Last accessed September 2019).
12 Potter N., K. Rajagopalan, and M. Brady. (2018) Using Climate Analogues to Obtain a Causal Estimate of the Impact of Climate on Agricultural Productivity. Proceedings of Agriculture and Applied Economics Association Annual Meeting, Washington D.C.
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Chapter VI Priority Needs
The agricultural community in Snohomish County is facing many current and projected challenges associated Farmland Conservation with increased development and a changing climate. Through a stakeholder led prioritization process, PCC Through a robust community engagement process, Farmland Trust and partners on the Snohomish Farmland farmers provided priority resilience needs for their Conservation Working Group identified a 10-year specific reach. This chapter documents the major protection target of 15,000 acres of high priority farmland. themes raised during this community engagement Much of Snohomish County’s commercial farmland is in process. The chapter is followed by eleven individual the floodplain, where state and local regulations provide Reach Summaries (Chapter VII) that characterize partial barriers to conversion of the land. Still, many farms existing farming and infrastructure, projected impacts to in both the floodplains and upland areas continue to be agricultural viability, and prioritized resilience needs. lost to development, habitat restoration, businesses, and other uses. While this 10-year acreage target does Addressing the following resilience needs will require include upland agricultural land protection goals, a partnership building, innovative approaches to problem focus on farms utilizing the highly productive soils of solving, creative thinking, and funding acquisition. the floodplains is critical to ensure a viable agricultural Farmers highlighted the need for grant and/or loan system in the county. funding to help them address many of these issues described below. Existing funding sources for Purchase of Development Rights (PDR) and Transfer of Development Rights (TDR) Priority needs include farmland conservation, drainage programs are insufficient to reach the 10-year protection infrastructure and maintenance, compensation for target or satisfy farmer interest. In addition, the per upland runoff, flood protection, access to irrigation water, acre easement payments to farmers through these two drought resilience practices, and additional groundwater programs are often too low to incentivize participation. analysis. Potential options for increasing funding available include growing the TDR program, securing grants, and/or leveraging additional taxes.
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Drainage Infrastructure Compensation for and Maintenance Upland Runoff Diking, drainage, and flood control districts across the Development of upland areas has resulted in increased County consistently report insufficient funding to manage runoff reaching floodplain areas, in many cases current drainage needs, citing runoff from upland areas exacerbating drainage challenges for farmers. A few and increased flooding as major impacts. Climate change diking, drainage, and flood control districts have projections indicate increased stormwater runoff and agreements with local jurisdictions to collect stormwater flood frequency and scale, highlighting the need for fees to help offset the costs associated with increased improvements to and increased capacity of drainage runoff and sediment, while most do not. There is a need systems. to work with individual districts and local jurisdictions to help develop these compensation agreements and Many agricultural areas require a drainage needs potentially increase revenue under existing agreements. assessment to inform projects that would increase capacity of existing culverts, tide gates, and pump Projects or initiatives to reduce upland runoff would also stations as well as replace aging infrastructure. greatly benefit farmers. These potentially include use Assistance acquiring and complying with permits of green stormwater infrastructure, regulatory changes for infrastructure improvement projects as well as to county and city development codes, and education regular maintenance of drainage conveyances is or incentives for urban and suburban landowners and critical. In addition, individual farms would benefit from developers to reduce runoff from their properties. increased technical and funding assistance for drainage improvements.
Farming a few feet above sea level “In drier years, farming a few feet above sea level is always a bit of a gamble. Yet as the clouds build and the winter rain falls, I wonder if it is a matter of climate change or all the development (and its consequential gutters, pavement, and sewer lines) that encircle the valley. Are we building an agricultural legacy, or an urban drain field?” Nick Pate, Raising Cane Ranch, Photovoice 2017
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Washington State, including the issuance of water rights. Flood Protection At this time, applying for new water rights is not a feasible While farms in the floodplain are often inundated in option for farmers as basins are closed to additional winter months, damages are minimized and spring water withdrawals. drainage made possible through a system of sea dikes, river levees, and riverbank protection projects. In many There is a need for creative approaches to providing places, this flood protection infrastructure is in need access to water for farmers. Potential options include of improvement or replacement, and in others, there is allowance of water withdrawals or capture during winter a need for additional protection. With flood frequency months, on-farm water storage, and/or the coordinated and severity predicted to increase, impacts to this management and leasing of water rights at a landscape infrastructure will increase. scale.
In the upper reaches of the watersheds, flood protection (in the form of bank stabilization) is needed to protect Assistance Implementing against loss of farmland to a migrating river channel. In the lower floodplain, flood protection needs include levee Drought Resilience Practices maintenance, flood fencing and waterbreak planting There are numerous techniques that can be used to to lessen sediment and debris deposition on farms. increase a farm’s resilience to drought or to reduce Larger landscape-scale projects or approaches to water the need for irrigation. Existing incentive and grant management that increase the capacity of the floodplain programs through the state and federal government or channel to store flood waters are also recommended provide cost-share funding for practices that build soil if they lessen the impacts of flood events on farm water holding capacity, hold and/or store water, and infrastructure, protect banks, and improve agricultural increase irrigation efficiency. These programs, however, productivity. Finding creative solutions to increasing water are often highly competitive or pay low rates. With storage on farmland, while reducing the negative impacts climate predictions indicating hotter and drier summers, of long-term inundation and meeting increased spring additional funding is needed to incentivize practices such drainage needs, could provide a win-win for farm, flood, as cover cropping, no-till, compost or biochar application and wildlife interests. and agroforestry. In addition, research and/or on-farm trials of newly developing drainage infrastructure, such as controlled release of water from drain tiles or drainage Access to Irrigation Water ditches, is needed. Many farms do not have legal water rights, yet have a need for irrigation water to maintain their viability. Any withdrawal of surface water requires a water right and most commercial withdrawals of groundwater do as well. Climate change projections indicate the need for irrigation water will increase with less precipitation falling in summer months and with increasing temperatures. The Department of Ecology manages water resources in
“We may have enough water now but we may not have enough in five years. We need to be looking to the future.”
Jesse Allen, farmer, Photovoice 2017
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Additional Groundwater Other Needs Analysis While the intent of this Agriculture Resilience Plan is to focus on needs and actions to make the agricultural land Further study of groundwater levels and saltwater itself more viable and resilient to future change, farmers intrusion are recommended in the estuaries of the also provided valuable feedback into other market, Stillaguamish and Snohomish Rivers to validate predicted research, and education-related needs. These include: impacts of sea level rise on farmland. • Assistance complying with regulations – The costs In the Lower Stillaguamish River floodplain, projections of and time associated with complying with county and for saltwater intrusion on Florence Island and in Drainage state regulations puts incredible pressure on farmers, District 7 have been extrapolated from groundwater well particularly smaller operations. data south of Hatt Slough. Cardno, the consultant who completed the groundwater assessment for this project, • Research into new crop varieties – The impacts of recommends collection and analysis of additional well changing land use, climate, and markets continues data in these specific locations. to necessitate research into crop varieties that are resilient, drought tolerant, salt tolerant, and/or slower to In the Lower Snohomish River floodplain, projections of mature. groundwater levels on Ebey Island and in Diking Districts • Improvement of market infrastructure – Processing 2 and 4 have been extrapolated from groundwater well facilities and equipment as well as venues for selling data on Smith Island. If increased pumping is considered local products would assist in market expansion. as a tool to combat a rising groundwater table, further study is recommended to determine if this will result in • Flood risk training for new landowners – New upward migration of salty groundwater thus impacting farmers moving into the floodplain could benefit crop yields. greatly from training on how to minimize flood risk by accessing flood data available through Snohomish County as well as future flood projections.
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Chapter VII Reach Summaries
The following Reach Summaries characterize existing farming and infrastructure, projected impacts to agricultural viability, and prioritized resilience needs for eleven reaches within the Stillaguamish and Snohomish River floodplains (Figures VII-1 and VII-2 below). Through a robust community engagement process, farmers first learned about projected changes to flooding, groundwater, land subsidence and weather. Over 75 local farmers engaged in this process whereby they identified priority actions needed to ensure agricultural resilience into the future. Within each reach summary, the Resilience Needs section represents the primary needs identified by the farmers and categorizes them into tier one and tier two to guide implementation efforts.
The Steering Committee recommends an adaptive, county-wide approach to implementing these needs using criteria that includes likelihood of success, cost-benefit, availability of funding, and benefit to county-wide agriculture.
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I 5 Map Detail WA
S k a g i t C o u n t y S n o h o m i s h C o u n t y Skagit Bay Drainage District 7
Stanwood North and South Forks Stillaguamish River
Port Susan
WA 530 Stillaguamish Flood Control District Arlington
Middle Stillaguamish
Marysville WA 9
0 5 Granite Falls ± Miles
Figure VII-1 . Stillaguamish River floodplain reaches . Four sections of the floodplain were delineated based on drainage and flood control district boundaries, floodplain dynamics, and agricultural resilience needs.
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Marysville DikingDiking Districts Map Detail 22 and 4 WA Possession Lake Sound Stevens
Ebey Island - Diking District 1
Drainage District 13 Snohomish French Slough Flood Control District
Everett Marshland Lower Skykomish Flood Control US 2 Monroe District Sultan Gold Bar I 5 WA 9 Mill Creek
Lynnwood Snohomish River Confluence Bothell S n o h o m i s h C o u n t y K i n g C o u n t y 0 5 ± Miles
Figure VII-2 . Snohomish River floodplain reaches . Seven sections of the floodplain were delineated based on diking, drainage and flood control district boundaries, floodplain dynamics, and agricultural resilience needs.
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South Skagit Flats – Drainage and Diking Improvement District 7
Skagit County Map Detail
S n o h o m i s h C o u n t y
W
N
e
v
A King County
h
t 8 S k a g i t *# 6 B a y I-5
76th Ave NW *# y w
H
c i f i 300th St NW c
a
P
d l
O *# Drainage District 7 284TH ST NW
80th Ave NW
*# ' Pump Station 271st St NW WA-532 ' *# Flood/Tide Gate
Stillag Levees and Dikes u
a
m
i s Reach Boundary
72nd Ave NW
Stillaguamish h Flood Control R 0 0.5 iver Mile ± District ' Figure VII-3 . Map of Drainage District 7 . This figure shows the boundary of Drainage and Diking Improvement District 7, along with the locations of existing levees and tide gates.
Description Drainage and Diking Improvement District 7 is the DRAINAGE AND FLOOD PROTECTION agricultural zone north of the City of Stanwood to the Drainage District 7 manages the water conveyances that County line along Skagit Bay. Of the total 1,850 acres in flow from the uplands through the District into Skagit Bay. active agriculture, several hundred acres of high value The District also manages a sea dike protecting farmland seed crops are rotated with approximately 800 acres of and the City of Stanwood from tidal inundation and storm cereal grains. There is one commercial dairy managing surges. Most of the waterways in this area gravity-drain approximately 500 acres of the feed crops along with through tide gates at the bay, with the exception of Irvine several hundred acres of vegetables.
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Slough at the southern end which drains through a pump GROUNDWATER LEVELS AND DRAINAGE station operated by the City of Stanwood. The District is Groundwater levels in this area correlate with the height of actively working to secure funds to bring the sea dike up Puget Sound. While the projected rise in local sea levels to Army Corps of Engineers standards so the agency will ranges greatly, median values indicate an increase of 8 assist with dike maintenance and repair flood damages. inches by 2050 and over 2 feet by 2100 (RCP 8.5 50th Several areas of the dike are currently too low and/or too percentile values).2 This translates into an increase in the narrow to meet standards. height of the groundwater table on agricultural lands, which can impact the timing of crop cultivation and hay ZONING harvest in the spring. A groundwater study completed as part of this plan calculated delays in spring cultivation The agricultural land in this area is zoned Agriculture-10 based on sea level rise projections and found projected Acre. This zoning designation, along with additional median delays of several weeks throughout the lower protections provided by the density fringe regulatory portion of the Stillaguamish Valley. While the study does framework, make development in this area difficult. not include most of Drainage District 7, assumptions Subdivision of larger farms into smaller farms, however, that the same mechanisms are at play indicate similar does threaten the viability of the interconnected system of projections as those shown for Florence Island. This forage, feed, and seed crops. would mean median delays of five weeks predicted by the year 2080 (RCP 8.5).3
Current and future impacts These projected sea level rise impacts on groundwater FLOODING will exacerbate already occurring drainage challenges Currently, the main source of flooding in the District is caused primarily by flooding from upland runoff. surface water runoff from the uplands, but sea level rise Snohomish County completed a study of drainage needs projections point toward the likelihood of increasing for the lower portion of the District (Unnamed Slough, impacts from coastal flooding. This area is also at risk if Douglas Creek, and Irvine Slough) in 2014 and 2015 to 4,5 the levee along the Skagit River breaks near Conway. develop a plan to decrease lowland flooding. Modeling indicated that projects aimed at increasing water New modeling work completed for this planning detention in the uplands would only marginally reduce the 4 effort shows a projected increased frequency of sea impact upland runoff has on lowland flooding. Several dike overtopping as a result of sea level rise and the scenarios for improving flood water conveyance through associated coastal flooding.1 The modeling work culvert replacements and channel excavation within completed is at a coarse scale (10m) and is thus most the District were recommended to improve drainage for appropriate for general risk assessment and planning farmers. purposes, not for site-level analysis. It shows, however, that current overtopping occurs during the 25-year SALTWATER INTRUSION TO GROUNDWATER coastal flood event (4% annual chance) and is expected As sea level continues to rise, the intrusion of salt into the to occur at the 2-year coastal flood event (50% annual groundwater could have yield impacts on crops grown in chance) by mid-century.1 There are plans currently the District. A groundwater study completed as part of underway to raise and fortify the sea dike in several this plan indicates that a portion of Florence Island may places, which would reduce this frequency. More detailed already be experiencing yield impacts.3 While the study site-specific hydraulic modeling would better inform the does not include Drainage District 7, similar mechanisms understanding of the future risk of saltwater inundation. are likely at play and would indicate similar projections as those shown for Florence Island. Producer testimony confirms this is true in patches. The amount of freshwater coming off the hill, however, may mean reduced
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saltwater impacts in the groundwater as compared to the the northern section would likely yield similar results. projections for Florence Island. Installation of pumps and In addition, upgrades to tide-gates would improve drainage infrastructure to reduce the impacts of rising farmland drainage and potentially provide benefits to groundwater levels in Drainage District 7 may result in fish habitat. pulling salty groundwater upward and further negatively • Funding for drought resilience Best Management impacting crop yields. Practices . Existing incentive programs do not pay sufficient rates for practices that build soil health and OTHER increase the water holding capacity of soils. Funding Other current and projected impacts: and equipment is needed for practices such as cover cropping, no-till, compost or biochar application, and • Farmers have seen an increased need for irrigation agroforestry. Developing ecosystem service markets in recent years. Many farmers have not traditionally for carbon sequestration or water quality could provide irrigated and do not have water rights. Lack of available funding for these practices and increase the economic water rights threatens crop yields and the willingness of resilience of farms. seed companies to sign contracts with local farmers. TIER TWO (LOWER PRIORITY) • Financial assistance for drainage system Resilience Needs maintenance . Increased upland stormwater runoff and increased flooding as a result of climate change will TIER ONE (HIGH PRIORITY AND IMMEDIATE) stress an already financially limited drainage district. • Access to water for irrigation . Most farms do not Assisting the District in securing agreements with local have water rights, and while many have not traditionally jurisdictions to compensate for upland stormwater needed to irrigate, higher temperatures and less runoff would support ditch and waterway maintenance. summer precipitation has resulted in higher irrigation Farmers would also benefit from assistance with needs in recent years. With rising sea levels, existing replacing or installing drainage infrastructure on ditches may or may not be able to provide freshwater individual farms. for irrigation into the future. There is a need for creative approaches to sourcing freshwater for irrigation in this • Additional groundwater well data collected and District. analyzed . Projections developed in this study used data from wells just south of Hatt Slough and on • Sea dike improvements . The goal of the District is Camano Island. Additional well data and analysis in to bring the sea dike up to Army Corps of Engineers Drainage District 7 and the surrounding area could standards and enroll it in the PL84-99 program to better validate the projections. protect farmland and the City of Stanwood and to provide the assurance that breaches will be repaired by • Reduce upland runoff . A modeling effort completed the agency. This would require raising and widening the for Snohomish County concluded marginal dike in places. This may also result in re-routing lower improvements to lowland drainage would result from Douglas Creek and/or adding a pump station. implementation of upland detention efforts.4 However, this work could help mitigate for future climate change • Drainage infrastructure improvements . To improve and development. existing drainage and increase resilience to future groundwater and flooding impacts, several projects are • Research on new crop varieties . Research into new recommended. Snohomish County identified numerous crop varieties and markets that are more resilient to culverts that need to be upsized and channels that changes in the landscape may help farmers offset need to be excavated to increase capacity in the losses in production of existing crops. Funding for southern section of the District.5 An assessment of infrastructure and processing may also be needed.
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Lower Stillaguamish River – Stillaguamish Flood Control District
Old 99
*# Drainage 276TH ST NW N 276th St NW Woodland Rd Skagit County District 7 Old 99 N *# 271st St NW 272ND ST NW ' Map *# Detail S n o h o m i s h 268th St NW 28thAve NW *# W Sunday Lake Rd C o u n t y WA-522
*# 72ndAve NW *# King County *# *# 64th Ave NW ' Sunday Lake Rd *# *#
Stillaguamish Flood Control District
Norman Rd amish gu R a i ll ve ti r S
d n R *# rso La Middle Stillaguamish 220th St NW ' Pump Station F ra *# n Flood/Tide Gate ' k Happy Hollow Rd W
50thAve NW Levees and Dikes a te r s Reach Boundary R d 0 0.5 Mile ±
Figure VII-4 . Map of the Stillaguamish Flood Control District . This figure shows the boundary of the Flood Control District and the locations of existing levees, flood control gates, and pump stations.
Description The Lower Stillaguamish River Valley contains one of of active agricultural land. There are six commercial the largest areas of contiguous commercial agriculture dairies managing the bulk of the forage and feed crops in Snohomish County. The valley supports an integrated along with numerous beef and smaller livestock-based system of cropping that relies on field rotations and farming operations. In addition, there are smaller areas of coordination between multiple farmers to support the agricultural land dedicated to growing berries, vegetables, seed production industry. Feed crops (hay and corn), and other crops. cereal grains, potatoes, and seed crops rotate through approximately 4,500 acres of the total 5,100 acres
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DRAINAGE AND FLOOD PROTECTION Current and future impacts Flood protection and agricultural drainage is managed by the Stillaguamish Flood Control District, an entity that FLOODING uses fees collected from landowners within this area to Flow records for the Stillaguamish River are available maintain a system of river levees, sea dikes, tide gates, from 1928 to the present and show that the five largest and a pump station. Most of the area gravity-drains recorded floods have occurred in the last 15 years.6 through maintained tide and flood gates, and the District New modeling work completed for this planning effort maintains a pump station that assists with drainage on shows strong evidence for increased frequency and Florence Island in the winter and spring. The portion extent of flooding (2-, 10-, 25- and 100-year events) of land south of Hatt Slough (the Port Susan Pooling with particularly impactful changes for the more frequent Agreement area) also has a pump station that is used 2- and 10-year flood events.7 In the Stillaguamish River infrequently in the spring to augment gravity drainage watershed, the current flooding extent for the 2-year flood through a tide-gated culvert. Nearly the entirety of (50% annual chance event) is projected to more than Drainage District 12 is located within the boundaries of quadruple by the middle of the century, increasing from the Flood Control District. The District collects landowner 9,095 acres inundated to 38,575 acres.1 The frequency fees specifically for drainage system maintenance within of flood events is also projected to increase. Farmers its boundaries. in this area identified the 17-ft and 19-ft flood stages (at the Stillaguamish River at Arlington #34 gauge) as The levees, along with multiple shoreline armoring critical thresholds used for risk management (e.g. when projects, were built between 1870 and 1950, largely by levees overtop, livestock must be evacuated, structures local farmers. The river levees were raised in 2016, and flood, etc.). The models show that the 17-ft stage height both these and the sea dikes are in good condition. In is currently exceeded about one day per year and is 2013, most of the levee was certified to Army Corps projected to be exceeded for 3 days per year, on average, of Engineers standards and enrolled in the PL84-99 by the 2050s.7 The 23-ft flood is projected to happen program, which means that the federal agency will repair three times as often by the 2080s. levees that have been damaged as a result of a flood. The agency will also assist with the costs, permitting, and design of regular levee maintenance, although this is LAND SUBSIDENCE ultimately the responsibility of the District. A study of land subsidence completed for the Flood Control District indicates that some areas of the landscape may be sinking minimally due to the cultivation ZONING and subsequent decomposition of organic soils as well Aside from the small portion of the Lower Stillaguamish as the depletion of groundwater.8 The area of greatest Valley within the city limits of Stanwood, the agricultural impact appears to be northeast of the railroad in the land in this reach is zoned Agriculture-10 Acre. This Miller Creek drainage, although the rate of 4 inches of zoning designation, along with additional protections subsidence between 2003 and 2015 had such a high provided by the density fringe regulatory framework, margin of error that the result was inconclusive. make development in this area difficult. Subdivision of larger farms into smaller farms, however, does threaten the viability of the interconnected system of feed, cereal GROUNDWATER LEVELS grains, and seed crops as farmers rotate ground amongst Groundwater levels in the lower valley correlate with each other regularly. the height of Puget Sound and river flood levels. While projections of the rise in local sea levels range greatly, median values indicate an increase of 8 inches by 2050 and over 2 feet by 2100 (using RCP 8.5 50th percentile values).2 This translates into an increase in the height of
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the groundwater table on agricultural lands which can impact the timing of crop cultivation and hay harvest in Resilience Needs the spring. A groundwater study completed as part of TIER ONE (HIGH PRIORITY AND IMMEDIATE) this plan calculated delays in spring cultivation based on • Access to water for irrigation . Most farms do not sea level rise projections and found a projected median have sufficient water rights, and while many have not delays of several weeks throughout the lower portion traditionally needed to irrigate, higher temperatures of the valley. On Florence Island, median delays of five and less summer precipitation has resulted in higher weeks are predicted by the year 2080 (RCP 8.5).3 irrigation needs in recent years. There is a need to develop creative approaches to providing irrigation SALTWATER INTRUSION TO GROUNDWATER water to farmers. As sea levels continue to rise, the intrusion of salt into • Drainage infrastructure improvements . To improve groundwater could have yield impacts on crops grown in existing drainage and increase resilience to future the Lower Stillaguamish. A groundwater study completed groundwater and flooding impacts, several projects as part of this Plan indicates that a portion of Florence are recommended. Tide and flood gates in several Island may already be experiencing yield impacts, and locations need to be upsized to pass higher projected 3 producer testimony confirms this is true in patches. The flood and stormwater flows as well as improve drainage projections show yield impacts expanding to include in the spring. nearly all of Florence Island by 2100. Installation of pumps and drainage infrastructure to reduce the impacts • Additional groundwater well data collected and of rising groundwater levels in the lower portion of the analyzed . Projections developed for groundwater District could result in pulling salty groundwater upward levels and saltwater intrusion used data from wells and further impacting crop yields. just south of Hatt Slough and on Camano Island. Additional well data and analysis on Florence Island and the surrounding area could validate the projections OTHER provided. Other current and projected impacts: • Reduction in flood damages . Infrastructure damage • Continued increases in surface water drainage coming caused by flooding puts added financial burden on an from upland areas cause sedimentation of drainage already economically distressed industry. Increasing the ditches and increased drainage issues. capacity of the river and floodplain to hold floodwater, if done strategically, could reduce flood impacts on • Farmers have seen an increased need for irrigation surrounding farms. in recent years. Many farmers have not traditionally irrigated and do not have water rights. Lack of available • Financial assistance for drainage system water rights will threaten viable crop yields. maintenance . Increased upland stormwater runoff and increased flooding as a result of climate change will • Economic pressures for producers are resulting in stress an already financially limited flood control district. subdivision of large farms and reduction of the available Assisting the District in securing agreements with local acreage needed for current commercial farmers who jurisdictions to compensate for upland stormwater are dependent on land rotation. runoff would support ditch and waterway maintenance. Farmers would also benefit from assistance with replacing or installing drainage infrastructure on individual farms.
• Increased funding for larger levee and drainage infrastructure projects . Although levees and pumps are in good condition, there is no contingency plan
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for future repair and/or replacement needs. Options and partnerships for developing a grant and/or loan program for larger resilience projects should be explored.
• Research on new crop varieties . Research into new crop varieties and markets that are more resilient to changes in the landscape may help farmers offset losses in production of existing crops. Funding for infrastructure and processing may also be needed.
• Funding for drought resilience Best Management Practices . Existing incentive programs do not pay sufficient rates for practices that build soil health and increase the water holding capacity of soils. Funding and equipment is needed for practices such as cover cropping, no-till, compost or biochar application, and agroforestry. Developing ecosystem service markets for carbon sequestration or water quality could provide funding for these practices and increase the economic resilience of farms.
TIER TWO (LOWER PRIORITY) • Conserve existing farmland . The system of crop rotations in the valley necessitates maintenance of the existing agricultural land base. Loss of farmland to subdivision or habitat restoration threatens the viability of seed farms and will continue to result in loss of agricultural services that support farmers. Existing funding sources for Purchase of Development Rights (PDR) and Transfer of Development Rights (TDR) programs are insufficient to protect farmland at the landscape scale. Innovative approaches should be pursued to increase the funding available to remove development rights and also allow for other potential uses such as restoration if farming is no longer viable in the future.
• Improve flood warning system . Farmers have very little time to prepare for floods and limited flood warning information. Real-time gauges, more sophisticated predictions, and improved notification to farmers are needed.
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Middle Stillaguamish River – Silvana to Arlington
d R Skagit County w e i v Map d Detail n a S n o h o m i s h r S n o h o m i s h
268th St NE Stanwood-Bryant Rd G C o u n t y WA-532
King County Pio nee r H I-5 wy Stillaguamish Flood Control District 19th Ave NE 236th St NE North and South Forks Stillaguamish River 220th St NW H a Stillaguamish River p p
y
V Middle
a
l N French Ave l Stillaguamish
e y Sill Rd
R 204TH ST NE d Cemetery Rd S m Armoured Banks o k Levees and Dikes e y Reach Boundary P
o
i n 0 1 t Mile ±
19th Dr NE
B
l v
Figure VII-5 . Map of Middle Stillaguamish River floodplain . This figured shows the boundary of the Middle Stillaguamish River reach along with existing levees and revetments.
Description The Middle Stillaguamish River Valley supports a robust DRAINAGE AND FLOOD PROTECTION commercial agricultural industry yet faces development This area is not managed by an organized diking or pressures due to its proximity to Interstate 5 and the City flood control district. The levees are not contiguous as of Arlington. Feed crops (hay, pasture, and silage corn), in the Lower Stillaguamish, but rather provide protection cereal grains, and seed crops dominate the landscape, against flood flows and debris at strategic locations utilizing approximately 2,800 acres of the total 3,800 along the river. The levees were largely built by the U.S. acres in active agriculture. There are four commercial Army Corps of Engineers between 1920 and 1950 and dairies managing the bulk of the feed crops, along with continue to be managed by the agency today. The Corps smaller areas dedicated to growing vegetables or nursery also constructed many shoreline armoring projects that stock, and raising beef and small livestock.
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are now managed by individual farmers. There are a intersection of Highway 530 and Interstate 5 will have on few sections of levee that are managed by Snohomish local flooding. County. The major impacts of flooding in this reach include:
ZONING • Sand and silt deposition on fields, which can result in The agricultural land in this reach is primarily zoned decreased yields Agriculture-10 Acre, aside from the small portion of the floodplain that was annexed into the City of Arlington. • Soil erosion, which occurs along concentrated flow Extra protections against development or subdivision of paths in fields large farms are provided by the density fringe regulatory • Flood debris on fields, which requires costly clean-up framework, although these protections do not extend and repair east of Interstate 5. Loss of commercial farmland to development or subdivision is a real threat in this reach • Damage to structures, which results in costly repair due to the proximity to a growing urban center and the lack of density fringe protections east of Interstate 5. • Threats to livestock, including harm to animals, decreased milk production, or impacted milk transport
• Bank erosion, which causes loss of farmland and Current and future impacts threats to levees FLOODING Flow records for the Stillaguamish River are available GROUNDWATER LEVELS AND from 1928 to the present and show that the five largest SALTWATER INTRUSION recorded floods have occurred in the last 15 years.6 Groundwater levels and saltwater intrusion in the Middle New modeling work completed for this planning effort Stillaguamish are not expected to be impacted by rising shows strong evidence for increased frequency and sea levels due to the steep gradient of the valley and extent of flooding (2-, 10-, 25- and 100-year events), distance from the Puget Sound.3 Groundwater levels may with particularly impactful changes for the more frequent be impacted by increased riverine flooding or upland 2- and 10-year flood events.7 In the Stillaguamish River stormwater runoff, although these effects are predicted to watershed, the current flooding extent for the 2-year flood be shorter in duration than the sustained impacts of sea (50% annual chance event) is projected to more than level rise downriver. quadruple by the middle of the century, increasing from 9,095 acres inundated to 38,575 acres.1 The frequency of flood events is also projected to increase. Farmers OTHER in this area identified the 17-ft and 19-ft flood stages Other current and projected impacts: (at the Stillaguamish River at Arlington #34 gauge) as critical thresholds used for risk management (e.g. when • Continued increases in surface water drainage coming levees overtop, livestock must be evacuated, structures from upland areas cause sedimentation of drainage flood, etc.). The models show that the 17-ft stage ditches and increased field inundation. height is currently exceeded about one day per year • Farmers have seen an increased need for irrigation and is projected to be exceeded for 3 days per year, on in recent years. Many farmers have not traditionally average, by the 2050s.7 The 23-ft flood is projected to irrigated and do not have water rights. Lack of available happen three times as often by the 2080s. Flood damage water rights will threaten viable crop yields. was a primary concern of producers in this reach, who have already noticed more intense and longer duration flooding than in the past. Farmers are concerned about the potential impacts recent development near the
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• Economic pressures for producers are resulting in • Funding for drought resilience Best Management subdivision of large farms and reducing the available Practices . Existing incentive programs do not pay acreage needed for current commercial farmers to be sufficient rates for practices that build soil health and viable. increase the water holding capacity of soils. Funding and equipment is needed for practices such as cover cropping, no-till, compost or biochar application, and Resilience Needs agroforestry. Developing ecosystem service markets TIER ONE (HIGH PRIORITY AND IMMEDIATE) for carbon sequestration or water quality could provide funding for these practices and increase the economic • Access to water for irrigation . Most farms do not resilience of farms. have sufficient water rights and while many have not traditionally needed to irrigate, higher temperatures and less summer precipitation has resulted in higher TIER TWO (LOWER PRIORITY) irrigation needs in recent years. There is a need to • Financial assistance to repair shoreline armoring . In develop creative approaches to providing irrigation the event of a large flood, which is projected to occur water to farmers. more frequently, existing shoreline armoring may be damaged on individual properties. • Reduction in flood damages . Crop yield impacts caused by flood-deposited sediment, soil erosion, • Financial assistance for drainage system and flood debris removal costs put added financial maintenance . Increased upland stormwater runoff burden on an already economically distressed industry. and increased flooding as a result of climate change Flood protection projects such as flood fencing and will increase the drainage burden of farmers in the waterbreak planting in strategic locations could floodplain. There is a need to explore ways to increase lessen the impact of inundation on individual farms. the funding available to include compensation for Bank erosion also damages levees or results in loss upland stormwater runoff impacts. of farmland. Increasing the capacity of the river and • Reduce upland runoff . There is a need to explore floodplain to hold flood waters, if done strategically, the use of green stormwater infrastructure, regulatory could reduce flood impacts on surrounding farms. changes to county and city code, and/or education and • Improve flood warning system . Farmers have incentives for urban/suburban landowners to reduce very little time to prepare for floods and limited impervious surfaces or implement drainage projects on flood warning information. Real-time gauges, more their properties. sophisticated predictions, and improved notification to • Farm pads . Assistance with funding and permitting to farmers are needed. install farm pads for livestock sanctuary and equipment • Conserve existing farmland . The proximity of this storage during floods would help mitigate the impacts floodplain reach to the City of Arlington and Interstate of projected higher intensity and more frequent 5, in addition to the lack of density fringe protections flooding. east of the freeway, make farmland protection a high • Research alternative on-farm drainage priority. Subdivision of farms threatens the viability of infrastructure techniques . There is a need to fund farming and will continue to result in loss of agricultural research and pilot projects looking at ways to better services that support farmers. Existing funding sources construct and manage drain tile or ditch systems to for Purchase of Development Rights (PDR) and Transfer hold water back during summer months. of Development Rights (TDR) programs are insufficient to protect farmland at the landscape scale. Innovative approaches should be pursued to increase the funding available to remove development rights.
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North and South Fork Stillaguamish River
u g h R Skagit County van a d C a e Map a k Detail L S n o h o m i s h C o u n t y
King County WA-9 North and South Forks Stillaguamish River
WA-530 G ra n d v ie w R d
Stillaguamish River
252nd St NE R d e k C re Jim
228th St NE
Middle Levees and Dikes Stillaguamish J Reach Boundary o r d Armoured Banks a n
R 0 1 d Mile ±
Figure VII-6 . Map of North and South Forks of the Stillaguamish River floodplain . This figure shows the boundary of the North and South Fork Stillaguamish River reach along with existing levees and revetments.
Description While the floodplain narrows above the confluence of the The North and South Fork Stillaguamish area represents North and South Fork Stillaguamish River, commercial approximately 3,000 acres of commercial agricultural land agriculture remains viable and is critical in supporting predominately in feed and forage production to support the larger agricultural industry in Snohomish County. The the livestock industry and two commercial dairies. In primary agricultural production zone extends partway up addition, smaller acreages support production of cereal the South Fork where the floodplain width allows, and up grains, seed crops, and forestry. the North Fork past Oso.
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DRAINAGE AND FLOOD PROTECTION Resilience Needs This area is not managed by an organized diking or flood control district. Existing levees are not contiguous as in TIER ONE (HIGH PRIORITY AND IMMEDIATE) the Lower Stillaguamish, but rather provide protection • Reduction in flood damages . Crop yield impacts against flood flows and debris at strategic locations caused by flood-deposited sediment, soil erosion, along the river. The levees along with multiple shoreline and flood debris removal costs put added financial armoring projects were built primarily between 1920 and burden on an already economically distressed industry. 1950, largely by the Army Corps of Engineers. Individual Flood protection projects such as flood fencing and farmers maintain drainage infrastructure as well as waterbreak planting in strategic locations could shoreline armoring projects on their properties. lessen the impact of inundation on individual farms. Bank erosion also damages levees or results in loss of farmland. Increasing the capacity of the river and ZONING floodplain to hold flood waters, if done strategically, The agricultural land in this reach is primarily zoned could reduce flood impacts on surrounding farms. Agriculture-10 Acre, although there are some areas where active commercial agricultural land is zoned Rural-5 Acre. • Protect farmland from riverbank erosion . Numerous The density fringe regulatory framework protections that bank stabilization projects were put in place in the early exist in downstream floodplain reaches do not extend to mid-1900s. Several of these have started to erode into this area, although much of the area is designated but new permit requirements have made it difficult as floodway. The floodway designation carries significant and costly for farmers to repair them or construct new restrictions on development (SCC 30.65.220), yet loss of projects. commercial farmland to development or subdivision is a • Conserve existing farmland . The proximity of this threat near the City of Arlington. floodplain reach to the City of Arlington makes farmland protection a high priority. Subdivision of farms threatens the viability of farming and will continue to result in loss Current and future impacts of agricultural services that support farmers. Existing FLOODING funding sources for Purchase of Development Rights (PDR) and Transfer of Development Rights (TDR) Flow records for the Stillaguamish River are available programs are insufficient to protect farmland at the from 1928 to the present and show that the five largest landscape scale. Innovative approaches should be recorded floods have occurred in the last 15 years.6 pursued to increase the funding available to remove New modeling work completed for this planning effort development rights. shows strong evidence for increased frequency and extent of flooding (2-, 10-, 25- and 100-year events) • Access to water for irrigation . Most farms do not with particularly impactful changes for the more frequent have sufficient water rights and while many have not 7 2- and 10-year flood events. In the Stillaguamish River traditionally needed to irrigate, higher temperatures watershed, the current flooding extent for the 2-year flood and less summer precipitation has resulted in higher (50% annual chance event) is projected to more than irrigation needs in recent years. There is a need to quadruple by the middle of the century, increasing from develop creative approaches to providing irrigation 1 9,095 acres inundated to 38,575 acres. The frequency of water to farmers. flood events is also projected to increase. Flood debris and the associated damage and clean-up costs are a concern for producers in this reach. In a few areas, bank erosion also threatens agricultural land.
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Snohomish River Estuary – Diking Districts 2 and 4
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Figure VII-7 . Map of Diking Districts 2 and 4 . This figure shows the boundary of the diking districts, along with existing levees and tide gates.
Description Diking Districts 2 and 4 are small districts along the DRAINAGE AND FLOOD PROTECTION eastern border of the estuary floodplain. Approximately Flood protection and limited agricultural drainage is 525 acres of the total 790 acres within the two districts managed by Diking Districts 2 and 4, entities that is in agricultural use. Farming consists of pasture (300 use fees collected from landowners within the area to acres), hay and silage (150 acres), and agritourism and maintain river levees and tide gates. Historically, the vegetable production (75 acres). County and City of Lake Stevens provided funding to Diking District 2 for drainage maintenance to compensate for upland runoff impacts, but that agreement has expired. Water gravity drains through the districts and out
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a series of tide gates along the levee. Flooding in these districts is primarily a result of upland drainage flowing off Current and future impacts the hill, as the levees rarely overtop. FLOODING Flooding of farmland in the Snohomish River Estuary The levees were built in the early 1900s. The diking is highly influenced by sea levels (tides and local storm and levee system in the Lower Snohomish River was surge) as well as river levels. In addition, Diking Districts constructed to provide flood protection for lower level 2 and 4 receive considerable upland runoff during floods, floods but not so high as to protect against water from making drainage maintenance in these districts highly larger events. In 1991, members of the Snohomish complex. River Coordinated Diking Council (Diking Districts 1-5, Drainage Districts 6 and 13, French Slough and New modeling work completed for this planning Marshland Flood Control Districts and a few private dike effort shows strong evidence for increased frequency managers) participated in development of the Snohomish and extent of flooding (2-, 10-, 25- and 100-year River Comprehensive Flood Control Management Plan events) with particularly impactful changes for the and agreed to maintain their levees at one foot above more frequent 2- and 10-year flood events.7 In the modeled 5-year flood levels.9 The result of this agreement Snohomish River watershed, projections indicate that has been that Diking Districts 2 and 4 rarely experience the acreage inundated in a 2-year flood will more than overtopping levees as flood pressure is released in double, increasing from 16,946 acres to 40,134 acres upriver floodplain areas first. by mid-century.1 The frequency of flood events is also projected to increase. Farmers in the Lower Snohomish The levees are not currently enrolled in the PL84-99 Army identified the 17-ft and 23-ft flood stages (at Monroe Corps of Engineers program; therefore, levee repair and gauge #12150800) as critical thresholds used for risk maintenance are the responsibility of the districts. Diking management (e.g. when levees overtop, livestock must District 2 is actively working to bring their levee up to be evacuated, structures flood, etc.). The models show Army Corps of Engineers standards so the agency will that the 17-ft stage height is currently exceeded about provide assistance. one day per year and is projected to be exceeded for 3 days per year, on average, by the 2050s.7 The 23-ft flood ZONING is projected to happen two to three times as often by the 2050s and three to four times as often by the 2080s. Diking District 2 is zoned Agriculture-10 Acre. This zoning designation, along with additional protections provided by While this modeling effort did not include flood the density fringe regulatory framework, make non-agri- projections for the smaller drainages coming from cultural related development in this area difficult. Despite the uplands, we can expect both land use changes these protections, subdivision of larger farms into smaller (development) and climate change to exacerbate the farms, as well as conversion to non-agricultural uses, impacts of upland runoff in Diking Districts 2 and 4. threatens the viability of commercial agriculture in this area so close to the urban centers of Everett and Lake Stevens. GROUNDWATER LEVELS Groundwater levels in Diking Districts 2 and 4 are Diking District 4, however, has approximately half its projected to be impacted by sea level rise. While the acreage in Agriculture-10 Acre zoning and half in Rural-5 predicted rise in local sea level ranges greatly, median Acre zoning. The portion zoned Agriculture-10 Acre also values indicate an increase of 10 inches by 2050 and has protections provided by the density fringe regulatory over 2 feet by 2100 (RCP 8.5 50th percentile values).2 framework, making non-agricultural related development Diking District 4 is over 3.5 miles from the mouth of in this area more difficult. Losing farmland to non-agri- the Snohomish River, yet the low gradient of the river cultural uses is a threat in the portion of the District zoned translates into groundwater level impacts from sea level Rural-5 Acre.
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rise throughout both districts. These increases may impact the timing of crop planting and hay cultivation in Resilience Needs the spring as well as the length of water inundation on TIER ONE (HIGH PRIORITY AND IMMEDIATE) fields. A groundwater study completed as part of this • Financial assistance for drainage system plan shows that Diking Districts 2 and 4 are predicted to maintenance . Increased upland stormwater runoff experience increases in the groundwater table similar to and higher groundwater tables (as a result of climate projected increases in sea level, resulting in considerably change) will stress already financially limited diking higher water tables by 2100.3 districts. There is a need to renew (District 2) and develop (District 4) agreements with cities and the SALTWATER INTRUSION TO GROUNDWATER county to compensate for upland stormwater and sediment impacts to drainage. A groundwater study completed as part of this Plan indicates that saltwater intrusion in groundwater is not • Drainage infrastructure improvements . To improve likely to be a threat to soils in these districts or other existing drainage and increase resilience to future agricultural lands in the vicinity due to the distance from groundwater and flooding impacts, several projects 3 the Puget Sound. Data from wells further upriver showed are recommended. These include improvements to no sign of saltwater intrusion, so data from Snohomish through-flow for streams and replacement of failed County wells on Smith Island were used to determine the culverts. Capacity of existing tide gates is sufficient, but potential impact in this area. Further study of groundwater these may require upsizing if upland runoff increases. levels and salinity is recommended in Diking Districts 1 (Ebey), 2, and 4 and Drainage District 13 to improve • Conserve existing farmland . The proximity of these the predictions calculated from the Smith Island well districts to the cities of Lake Stevens and Marysville dataset. In particular, if active pumping is considered as put development pressure on commercial farmland. a replacement to the existing gravity drainage system, Existing funding sources for Purchase of Development further study would be necessary to determine if this may Rights (PDR) and Transfer of Development Rights (TDR) result in pulling salty groundwater upward and impacting programs are insufficient to protect farmland at the crop yields. landscape-scale. Innovative approaches should be pursued to increase the funding available to remove There are several locations where salinity is currently development rights. impacting water in drainage ditches that had been • Funding for drought resilience Best Management used for irrigation in the past. If applied to farm fields Practices . Existing incentive programs do not pay unknowingly, this saline water could impact soil health sufficient rates for practices that build soil health and and crop yields. This lack of surface water for irrigation is increase the water holding capacity of soils. Funding impacting several local farms. and equipment is needed for practices such as cover cropping, no-till, compost or biochar application, and OTHER agroforestry. Developing ecosystem services markets Other current and projected impacts: for carbon sequestration or water quality could provide funding for these practices and increase the economic • Loss or subdivision of farmland in these districts is resilience of farms. reducing the available acreage needed for current commercial farmers to be viable as well as the feasibility of maintaining drainage infrastructure.
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TIER TWO (LOWER PRIORITY) • Access to water for irrigation . Most farms do not have sufficient water rights or are no longer able to withdraw from ditches now inundated with saltwater. While many have not traditionally needed to irrigate, higher temperatures and less summer precipitation has resulted in higher irrigation needs in recent years. There is a need to develop creative approaches to providing irrigation water to farmers.
• Reduce upland runoff . There is a need to explore the use of green stormwater infrastructure, regulatory changes to county and city code, and/or education and incentives for urban/suburban landowners to reduce impervious surfaces or implement drainage projects on their properties.
• Assistance with beaver management . Beaver presence along some waterways is impacting farmland drainage.
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Snohomish River Estuary – Diking District 1 –
Ebey Island
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S E Figure VII-8 . Map of Diking District 1 – Ebey Island . This figure shows the boundary of Diking District 1, along with existing levees, tide or flood control gates and pump station.
Description Ebey Island, in the estuary of the Snohomish River, Sound create a challenge for some slower ripening crops supports commercial agriculture, but in a limited capacity like corn.10 The Washington Department of Fish and due to the many challenges associated with this tidally Wildlife owns a significant portion of the island, managing influenced, low lying, and low gradient section of the 1,285 acres of the total 3,940, which they lease a portion floodplain. Approximately 41% of the island is in active of for farming. agricultural use, with successful farms producing cereal grains, hay, and forage (pasture grass). The cooler temperatures associated with the proximity to the Puget
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DRAINAGE AND FLOOD PROTECTION Current and future impacts Flood protection and agricultural drainage are managed by Diking District 1, an entity that uses fees collected FLOODING from landowners within the area to maintain a drainage The Snohomish River floodplain is low gradient with tidal system including ditches, tide/flood gates, a pump influence extending 16 miles upriver. Flooding in the station, and river levees. estuary around Ebey Island is influenced by river levels, tides and sea level rise, creating a “coastal squeeze” that The levees were built by the District and local farmers can exacerbate flooding issues and negatively impact in the early 1900’s along with multiple shoreline drainage of farmland. armoring projects. The diking and levee system in the Lower Snohomish River was constructed to provide New modeling work completed for this planning flood protection for lower level floods but not so high effort shows strong evidence for increased frequency as to exclude water from larger events. In 1991, the and extent of flooding (2-, 10-, 25- and 100-year Coordinated Diking Council was formed through events) with particularly impactful changes for the an Interlocal Agreement between Diking Districts more frequent 2- and 10-year flood events.7 In the 1-5, Drainage Districts 6 and 13, French Slough and Snohomish River watershed, projections indicate that Marshland Flood Control Districts and a few private the acreage inundated in a 2-year flood will more than dike managers agreeing to maintain their levees at one double, increasing from 16,946 acres to 40,134 acres foot above modeled 5-year flood levels.9 The result of by mid-century.1 The frequency of flood events is also this agreement has been that Ebey Island levees rarely projected to increase. Farmers in the Lower Snohomish overtop since the upstream districts overtop and fill up identified the 17-ft and 23-ft flood stages (at Monroe first, thus alleviating flood flows downstream. gauge #12150800) as critical thresholds used for risk management (e.g. when levees overtop, livestock must South of Highway 2, the island drains through several be evacuated, structures flood, etc.). The models show managed ditches and waterways to Deadwater Slough, that the 17-ft stage height is currently exceeded about near the highway, through a series of tide gates and a one day per year and is projected to be exceeded for 3 pump station. The District relies on gravity drainage most days per year, on average, by the 2050s.7 The 23-ft flood of the time, but typically pumps water between February is projected to happen two to three times as often by the and May to prepare for spring cultivation and pasture 2050s and three to four times as often by the 2080s. In growth. North of Highway 2, a section of the levee addition, sea level rise may further exacerbate flooding in overtops every winter, but this back-watering effect from the Lower Snohomish as higher water levels translate to the tides just fills the ditches with freshwater that sits higher storm surge heights. on top of the saltwater and does not negatively impact farmland production. Although the current 100-year flood (1% annual chance) does not overtop the levee on Ebey Island, the flood modeling projections indicate that the 100-year flood ZONING could start to overtop levees in the 2080s. While Ebey Island is zoned Agriculture-10 Acre. This zoning overtopping is infrequent, the increased pressure of designation, along with additional protections provided higher floodwaters may threaten the integrity of levees by the density fringe regulatory framework, make and lead to failure. non-agricultural related development in this area difficult. Subdivision of larger farms into smaller farms, however, To protect from current and future flood pressures, does threaten the viability of traditional commercial the levees protecting Drainage District 1 need to be agriculture in this area. reinforced in several places as a result of erosion on the river side. It can be difficult to get permits to place rip-rap, so the District resorts to reinforcing the levee
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on the inland side, resulting in a loss of farmland. Levee lands in the vicinity due to the distance from the Puget breaches, as opposed to overtopping, are the real Sound.3 Data from wells further upriver showed no sign of threat to farmland in the District. A recent levee breach saltwater intrusion, so data from Snohomish County wells was quickly plugged but posed a serious risk, while a on Smith Island were used to determine the potential levee breach in 1990 caused destruction to agricultural impact on Ebey Island. Further study of groundwater infrastructure and viability. levels and salinity is recommended in Diking Districts 1 (Ebey), 2, and 4, and Drainage District 13 to improve the An additional threat to levee integrity is the Highway 2 predictions calculated from the Smith Island well dataset. trestle, where bridge pilings rack large amounts of debris In particular, if increased pumping is implemented to during large floods. If not removed quickly, the debris acts combat drainage issues into the future, further study is as a dam, backing up water and threatening to blow out necessary to determine if this may result in pulling salty the levee behind the trestle. groundwater upward and impacting crop yields.
GROUNDWATER LEVELS LAND SUBSIDENCE Groundwater levels in the lower valley correlate with the Much of the land in the District was wetland associated height of the Puget Sound and river flood levels. While with the floodplain of the Snohomish River that has since the predicted rise in local sea level ranges greatly, median been drained for agricultural use. Approximately 1,200 values indicate an increase of 10 inches by 2050 and over acres are soils high in organic matter content that built 2 feet by 2100 (RCP 8.5 50th percentile values).2 This up over years of saturation. While only a portion of these translates into a similar but muted increase in the height soils are cultivated, cultivation has likely resulted in higher of the groundwater table on agricultural lands which can decomposition rates, causing the land to subside over impact the timing of crop cultivation and hay harvest in time. A study of subsidence rates completed for this the spring. A groundwater study completed as part of this planning effort in the Lower Snohomish River floodplain plan showed that Ebey Island groundwater levels were was inconclusive in this area.11 If subsidence is occurring, based both on river levels and sea levels making it hard to the impacts of sea level rise are likely to cause more determine the projected impacts of sea level rise.3 Maps significant impacts to drainage than subsidence. of existing and predicted ponded levels, however, show higher impacts into the future with a need for greater pumping in the spring to allow for planting and crop Resilience Needs growth (Figures V-5 and V-6). From the southernmost tip of Ebey Island and extending upriver through French TIER ONE (HIGH PRIORITY AND IMMEDIATE) Slough Flood Control District, delays in spring cultivation • Drainage infrastructure repair and improvements . based on sea level rise predictions were calculated. The The existing pumps are old and frequently being study found projected median delays of 4 weeks by 2050 repaired or rebuilt. There is a need to replace the and 5 weeks by 2080 on the southern tip of Ebey Island pumps to support continued and potentially increased (RCP 8.5).3 This study only looked at the impacts of sea pumping. In addition, many tide gates are failing and level rise on groundwater levels and did not take into in need of replacement, repair, or upsizing to protect account the ability of this district to actively pump water against floodwaters and projected increases in flood out of the system. Increased pumping, therefore, could heights and frequency. mitigate the impacts of these rising groundwater levels. • Levee improvements . Sections of the levee are in need of repair and reinforcement. Most of these are SALTWATER INTRUSION TO GROUNDWATER north of Highway 2. The District is currently working to A groundwater study completed as part of this Plan upgrade levees to Army Corps of Engineers standards indicates that saltwater intrusion is not likely to be a threat so they can be enrolled in the PL84-99 program. This to agricultural viability on Ebey Island or other agricultural will reduce the possibility of a levee breach and provide
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assurance that levee breaches or damage will be repaired by the agency.
• Additional groundwater well data collected and analyzed . Projections developed for groundwater levels and saltwater intrusion used data from wells downriver on Smith Island. Additional well data and analysis on Ebey Island and the surrounding area is needed to validate predictions and inform the impact of additional pumping on groundwater salinity.
• Protect levee from impacts of Highway 2 trestle . Several actions can be taken to lessen the impact and protect levees from debris racking on the Highway 2 pilings during flood events. One action could be to work with the State to develop a more proactive approach to removing debris before it poses a threat to farming infrastructure. Improvements to the levee adjacent to the trestle may also lessen the threat of a levee breach.
• Funding for drought resilience Best Management Practices . Existing incentive programs do not pay sufficient rates for practices that build soil health and increase the water-holding capacity of soils. Funding and equipment is needed for practices such as cover cropping, no-till, compost or biochar application, and agroforestry. Developing ecosystem service markets for carbon sequestration or water quality could provide funding for these practices and increase the economic resilience of farms.
TIER TWO (LOWER PRIORITY) • Financial assistance for drainage system maintenance . The drainage and pumping needs associated with higher groundwater tables as a result of sea level rise will stress an already financially limited diking district. There is a need explore ways to increase the funding available for drainage assistance.
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Lower Snohomish River – Drainage District 13 – Swans Trail Slough
52nd St SE Fobes R Skagit County Ebey Island - Skipley Rd Diking d St District 1 Lenora ' S n o h o m i s h C o u n t y
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Figure VII-9 . Map of Drainage Improvement District 13 . This figure shows the boundary of the Drainage District 13 reach, including existing levees, tide and flood control gates and a pump station.
Description Drainage Improvement District 13 is a narrow district DRAINAGE AND FLOOD PROTECTION nested between the Snohomish River and the largely Flood protection and agricultural drainage is managed developed Fobes Hill uplands. Just over 400 of the 580 by Drainage Improvement District 13, an entity that total acres in the District support commercial agriculture, uses fees collected from landowners within the area to primarily growing hay and silage as well as supporting maintain a system of ditches, river levees, and a pump cattle, small livestock, vegetables, fruit, agritourism, and station. Swans Trail Slough is a natural drainage that other smaller enterprises. collects water off the uplands and flows south to north
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along a sliver of farmland north of the old railroad grade. The railroad grade separates this drainage from a system Current and future impacts of managed ditches draining most of the farmland in FLOODING the District. These two systems meet up approximately The Snohomish River estuary is low gradient with tidal halfway up the District. The water from both systems influence extending 16 miles upriver to the confluence gravity-drains into Ebey Slough through a 6 ft diameter of the Skykomish and Snoqualmie Rivers near Monroe. tide gate when the water level in Ebey Slough is lower Flooding in Drainage District 13 is influenced primarily than Swans Trail Slough. When the water level in Ebey by river levels, but also by tides and sea level rise which Slough is high due to snow melt or storms, the District can exacerbate flooding issues and impact drainage of runs its 12-inch diameter fish-friendly pump to move farmland. water out of the District, primarily in the spring. In 2007, the District installed a new tide gate and pump. New modeling work completed for this planning effort shows strong evidence for increased frequency The levees were built in the early 1900s by local farmers. and extent of flooding (2-, 10-, 25- and 100-year The diking and levee system in the Lower Snohomish events) with particularly impactful changes for the River was constructed to provide flood protection for more frequent 2- and 10-year flood events.7 In the lower level floods but not so high as to protect against Snohomish River watershed, projections indicate that water from larger events. In 1991, members of the the acreage inundated in a 2-year flood will more than Snohomish River Coordinated Diking Council (Diking double, increasing from 16,946 acres to 40,134 acres Districts 1-5, Drainage Districts 6 and 13, French by mid-century.1 The frequency of flood events is also Slough and Marshland Flood Control Districts and a projected to increase. Farmers in the Lower Snohomish few private dike managers) participated in development identified the 17-ft and 23-ft flood stages (at Monroe of the Snohomish River Comprehensive Flood Control gauge #12150800) as critical thresholds used for risk Management Plan and agreed to maintain their levees at management (e.g. when levees overtop, livestock must one foot above modeled 5-year flood levels.9 The result be evacuated, structures flood, etc.). The models show of this agreement has been that Drainage District 13 that the 17-ft stage height is currently exceeded about levees overtop at the same time as both the Marshland one day per year and is projected to be exceeded for 3 and French Slough Flood Control District levees, relieving days per year, on average, by the 2050s.7 The 23-ft flood flood pressures and the risk of levee failure. The levee is projected to happen two to three times as often by the is not enrolled in the PL84-99 Army Corps of Engineers 2050s and three to four times as often by the 2080s. program and as such, levee repair and maintenance is the responsibility of the District. Higher intensity floods will mean more frequent overtopping of levees, although flood damage is not a ZONING major concern for farmers in this area. Higher and more frequent floods could, however, increase the potential for Drainage Improvement District 13 is zoned Agriculture-10 a levee failure, which would cause extensive damage to Acre. This zoning designation, along with additional farm and community infrastructure. protections provided by the density fringe regulatory framework, make non-agricultural related development in this area difficult. Despite these protections, subdivision GROUNDWATER LEVELS of larger farms into smaller farms as well as conversion Groundwater levels in Drainage District 13 are projected to non-agricultural uses threaten the viability of traditional to be impacted by sea level rise. While the projected rise commercial agriculture in this area so close to the urban in local sea level ranges greatly, median values indicate centers of Everett and Snohomish. an increase of 10 inches by 2050 and over 2 feet by 2100 (RCP 8.5 50th percentile values).2 Drainage District 13 is over eight miles from the mouth of the Snohomish
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River, yet the low gradient of the river translates into OTHER groundwater level impacts from sea level rise throughout Other current and projected impacts: the District. These increases may impact the timing of crop cultivation and hay harvest in the spring. A • Continued increases in surface water drainage coming groundwater study completed as part of this plan from upland areas cause sedimentation of drainage calculated delays in spring cultivation based on sea level ditches and increased field inundation. rise predictions. The study found projected median delays of 3-4 weeks by 2050 and 5 weeks by 2100 throughout • Economic pressures for producers are resulting in Drainage District 13 (RCP 8.5).3 This study only looked subdivision of large farms and reduction of the available at the impacts of sea level rise on groundwater levels acreage needed for current commercial farmers to be and did not take into account the ability of this district viable. to actively pump water out of the system. Increased pumping, therefore, could mitigate the impacts of these rising groundwater levels. Resilience Needs TIER ONE (HIGH PRIORITY AND IMMEDIATE) The existing tide gates are sufficient for the amount of • Drainage infrastructure improvements . To improve acreage that is drained, although increased flooding existing drainage and increase resilience to future and groundwater levels in the future may necessitate groundwater and flooding impacts, several projects the addition of another tide gate to improve gravity are recommended. These include improvements to drainage and reduce the need for additional pumping. the levee in specific locations, pump station capacity The tide gate pipes are over 30 years old and will need upgrades, and drainage system culvert replacements. replacement soon along with needed improvements to the adjacent levee. • Financial assistance for drainage system maintenance . Increased upland stormwater runoff and more intense flooding as a result of climate change SALTWATER INTRUSION TO GROUNDWATER will increase the drainage burden of farmers in this A groundwater study completed as part of this plan district. It would help to explore ways to increase indicates that saltwater intrusion is not likely to be a the funding available to include compensation from threat to agricultural viability in Drainage District 13 or upland stormwater runoff impacts to pay for ditch other agricultural lands in vicinity due to the distance from and waterway maintenance as well as to assist with the Puget Sound.3 Data from wells further upriver showed electricity costs for the pump station. no sign of saltwater intrusion, so data from Snohomish County wells on Smith Island were used to determine the • Reduce upland runoff . Explore the use of green potential impact in this area. Further study of groundwater stormwater infrastructure, regulatory changes to county levels and salinity is recommended in Drainage District and city code, and/or educating and incentivizing 13 and Diking Districts 1 (Ebey), 2, and 4 to improve the urban/suburban landowners to reduce impervious or predictions calculated from the Smith Island well dataset. drainage projects on their properties. Restoration of In particular, if increased pumping is implemented to Swans Trail Slough north of the railroad grade could combat drainage issues into the future, further study is also help to store or infiltrate upland runoff. necessary to determine if this may result in pulling salty groundwater upward and impacting crop yields. • Assistance with permitting for drainage system maintenance . Assist the District with the state and federal permitting process to allow for improved drainage system maintenance.
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• Funding for drought resilience Best Management Practices . Existing incentive programs do not pay sufficient rates for practices that build soil health and increase the water holding capacity of soils. Funding and equipment is needed for practices such as cover cropping, no-till, compost or biochar application, and agroforestry. Developing ecosystem service markets for carbon sequestration or water quality could provide funding for these practices and increase the economic resilience of farms.
TIER TWO (LOWER PRIORITY) • Conserve existing farmland . The proximity of this floodplain reach to the cities of Everett and Snohomish put development pressure on commercial farmland. Existing funding sources for Purchase of Development Rights (PDR) and Transfer of Development Rights (TDR) programs are insufficient to protect farmland at the landscape scale. Innovative approaches should be pursued to increase the funding available to remove development rights.
• Manage impact of nutria on levee integrity . Nutria are non-native invasive rodents whose burrowing can damage levee infrastructure and result in levee failure. It would help to assist with nutria control and/or eradication.
67 Agriculture Resilience Plan
Lower Snohomish River – Marshland Flood
) Controlp District o r p (
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83rdAve SE u Drainage g KingThre Countye La es Rd h King Countyk
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WA-9 Riverv iew R d L Lowell-Snohomish River Rd SE Ave 131st o w e l 88th St S l E - L a r Sn i oh m o 27thAve SE m ish R e i 100th St SE r Marshland ve R r d Flood Control District Westwick Rd
Marsh Rd
Airport Way French Slough
159th Ave SE 116th St SE Flood Control District 35thAve SE *# ' Pump Station *# Flood/Tide gate
51st Ave SE 132 Levees and Dikes nd St SE 134th Pl SE Reach Boundary Snohomish River 0 1 Mile ± Confluence Figure VII-10 . Map of Marshland Flood Control District . This figure shows the boundary of the Flood Control District, along with existing levees, tide or flood gates, and pump stations.
Description The Marshland Flood Control District spans the floodplain cereal grains (1,000 acres), hay or silage (800 acres), a south of the Snohomish River between the cities of commercial dairy, and other local livestock producers. Everett and Snohomish. Despite the proximity to these The District also supports grazing, vegetable production, two growing urban centers, over 70% of the District’s turf grass, and other agricultural related businesses such 6,400 acres is maintained as commercial agriculture. The as composting and agritourism. largest landholder operates a 1,500-acre blueberry farm. The other primary commercial farming enterprises include
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DRAINAGE AND FLOOD PROTECTION The pump station consists of two 100 hp pumps and four 250 hp pumps that move water from the District Flood protection and agricultural drainage is managed by into the Snohomish River. The pumps run throughout the Marshland Flood Control District, an entity that uses the year, but primarily between October and June. The fees collected from landowners within the area and from pump station does not provide fish access between the local jurisdictions to maintain a system of ditches, river Snohomish River and the District, allowing for a more levees, a flood canal, and a pump station. streamlined permitting process for drainage infrastructure maintenance. The levees were built in the early 1900s and upgraded with help from the Soil Conservation Service (now Natural Resources Conservation Service) in the early 1960s. ZONING The flood canal was dug and the pump station built with The Marshland Flood Control District is zoned federal help at that same time. The diking and levee Agriculture-10 Acre. This zoning designation, along system in the Lower Snohomish River was constructed with additional protections provided by the density to provide flood protection for lower level floods but not fringe regulatory framework, make non-agricultural so high as to protect against water from larger events. related development in this area difficult. Despite these In 1991, members of the Snohomish River Coordinated protections, subdivision of larger farms into smaller Diking Council (Diking Districts 1-5, Drainage Districts farms as well as conversion to non-agricultural uses 6 and 13, French Slough and Marshland Flood Control threaten the viability of traditional commercial agriculture Districts and a few private dike managers) participated in this area so close to the urban centers of Everett and in development of the Snohomish River Comprehensive Snohomish. Flood Control Management Plan and agreed to maintain their levees at one foot above modeled 5-year flood levels.9 The result of this agreement has been that the Marshland levee overtops at the same time as other Current and future impacts district levees, relieving flood pressures and the risk of FLOODING levee failure. In 2015, most of the levee was certified to The Snohomish River estuary is low gradient with tidal Army Corps of Engineers standards and enrolled in the influence extending 16 miles upriver to the confluence PL84-99 program so the federal agency will repair levees of the Skykomish and Snoqualmie Rivers near Monroe. if damaged as a result of a flood. The agency will also Flooding in the Marshland Flood Control District is design, obtain permits, and assist with 80% of the cost influenced primarily by upland runoff and river levels, of repairs, although levee maintenance is ultimately the although sea level rise is also projected to exacerbate responsibility of the District. flooding issues and impact drainage of farmland.
The Marshland Flood Control District receives a New modeling work completed for this planning considerable volume of water draining off the upland effort shows strong evidence for increased frequency areas within both unincorporated Snohomish County and extent of flooding (2-, 10-, 25- and 100-year and the City of Everett. This runoff results in deposition events) with particularly impactful changes for the of large volumes of sediment in the District’s ditches more frequent 2- and 10-year flood events.7 In the and flood canals. Sediment ponds have been built at six Snohomish River watershed, projections indicate that locations adjacent to Lowell Larimer Road to capture the acreage inundated in a 2-year flood will more than these deposits. The waterways within the District require double, increasing from 16,946 acres to 40,134 acres ongoing maintenance to clean out sediment and grass by mid-century.1 The frequency of flood events is also to maintain flow. The District receives funding from projected to increase. Farmers in the Lower Snohomish Snohomish County and the City of Everett to compensate identified the 17-ft and 23-ft flood stages (at Monroe for the increased impact of stormwater and sediment gauge #12150800) as critical thresholds used for risk inputs. management (e.g. when levees overtop, livestock must
69 Agriculture Resilience Plan
be evacuated, structures flood, etc.). The models show A study of subsidence rates completed for this planning that the 17-ft stage height is currently exceeded about effort in the Lower Snohomish River floodplain indicates one day per year and is projected to be exceeded for 3 rates of approximately 1 to 6 inches of subsidence every days per year, on average, by the 2050s.7 The 23-ft flood 10 years in some areas, although there is a large amount is projected to happen two to three times as often by the of error associated with this estimation.11 2050s and three to four times as often by the 2080s.
Most flood-prone structures in the District have been OTHER raised in recent years, so while higher intensity and more Other current and projected impacts: frequent floods will mean more levee overtopping, the greater risk is a levee failure. A levee breach would cause • Continued increases in surface water drainage coming extensive damage to farm and community infrastructure. from upland areas cause sedimentation of drainage One section of levee, in particular, is at risk of damage ditches and increased field inundation. as it receives considerable pressure from Pilchuck River • Farmers have seen an increased need for irrigation flood flows and deposited sediment. in recent years. Many farmers have not traditionally irrigated and do not have water rights. Lack of available GROUNDWATER LEVELS water rights will threaten viable crop yields. Groundwater levels in the Marshland Flood Control • Economic pressures for producers are resulting in District are projected to be impacted by sea level rise. subdivision of large farms and reduction of the available While the predicted rise in local sea level ranges greatly, acreage needed for current commercial farmers to be median values indicate an increase of 10 inches by 2050 viable. and over 2 feet by 2100 (RCP 8.5 50th percentile values).2 The Marshland Flood Control District is over seven miles from the mouth of the Snohomish River, yet the low Resilience Needs gradient of the river translates into groundwater level impacts from sea level rise through most of the District. TIER ONE (HIGH PRIORITY AND IMMEDIATE) These increases may impact the timing of crop cultivation • Access to water for irrigation . Most farms do not and hay harvest in the spring. A groundwater study have sufficient water rights, and while many have not completed as part of this plan calculated delays in spring traditionally needed to irrigate, higher temperatures cultivation based on sea level rise predictions. The study and less summer precipitation has resulted in higher found median predicted delays of 2-4 weeks by 2050 irrigation needs in recent years. There is a need to and 5 weeks through most of the District by 2100 (RCP develop creative approaches to providing irrigation 8.5).3 This study only looked at the impacts of sea level water to farmers. rise on groundwater levels and did not take into account • Reduce upland runoff . There is a need to explore the ability of this district to actively pump water out of the the use of green stormwater infrastructure, regulatory system. Increased pumping, therefore, could mitigate the changes to county and city code, and/or education and impacts of these rising groundwater levels. incentives for urban/suburban landowners to reduce impervious surfaces or implement drainage projects on LAND SUBSIDENCE their properties. Much of the land in this district was wetland associated • Reduce subsidence . Explore creative approaches to with the floodplain of the Snohomish River that has since reducing subsidence in areas where organic soils are been drained for agricultural use. As such, approximately decomposing, potentially through soil augmentation. 1,600 acres are soils high in organic matter. Cultivation and drainage of these soils has resulted in higher • Funding for drought resilience Best Management decomposition rates, causing the land to subside quickly. Practices . Existing incentive programs do not pay
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sufficient rates for practices that build soil health and • Research alternative on-farm drainage increase the water holding capacity of soils. Funding infrastructure techniques . The District could benefit and equipment is needed for practices such as cover from funding for research and pilot projects looking at cropping, no-till, compost or biochar application, and ways to better construct and manage drain tile or ditch agroforestry. Developing ecosystem service markets systems to hold water back during summer months. for carbon sequestration or water quality could provide funding for these practices and increase the economic resilience of farms.
TIER TWO (LOWER PRIORITY) • Additional financial assistance for drainage system maintenance . Increased upland stormwater runoff and more intense flooding as a result of climate change will increase the drainage burden on farmers in the floodplain. It would help to explore ways to increase the amount of stormwater runoff funding received from local jurisdictions to support ditch and waterway maintenance as well as assist with electricity costs to run the pump station. Farmers would also benefit from assistance with replacing or installing drainage infrastructure on individual farms.
• Flood risk training for new landowners . New farmers moving into the District could benefit greatly from training on how to minimize flood risk by accessing flood data and predictions available through Snohomish County and preparing for floods.
• Improve flood warning system . Farmers have very little time to prepare for floods and limited flood warning information. Real-time gauges, more sophisticated projections, and improved notification to farmers are needed.
• Conserve existing farmland . The proximity of this floodplain reach to the cities of Everett and Snohomish puts development pressure on commercial farmland. Existing funding sources for Purchase of Development Rights (PDR) and Transfer of Development Rights (TDR) programs are insufficient to protect farmland at the landscape scale. There is a need to pursue innovative approaches to increasing funding available to remove development rights.
71 Agriculture Resilience Plan
Lower Snohomish River – French Slough Flood Control District
F o s t e r S l o u g h
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S E
Skagit County
M R M R Rive w o ive rv ie a rview d 10th St Rd e e r r o o
131st Ave SE Ave 131st R S n o h o m i s h R S S n o h o m i s h d n C o u n t y d o 88th St h SE om ish River 171st Ave SE Map 1st St Detail King County Westwick Rd
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is R h - M e o k n a L ro e in a R h rt Way d Cathca C d v Rd l *# en B Flood/Tide wGate d O s Ol d ' Pump Station n Broadway Ave Snohomish a
l River e E MainLevees St andLower Dikes
y r
Confluence F Skykomish 179thAveSE Reach Boundary 164th St SE 0 1 Mile ±
Figure VII-11 . Map of French Slough Flood Control District . This figure shows the boundary of the Flood Control District, along with existing levees, tide or flood gates, and pump stations.
Description The French Slough Flood Control District spans the District). Another large portion (1,000 acres) is managed floodplain between the cities of Snohomish and Monroe. as private duck hunting clubs, which utilize a portion Despite the proximity to these growing urban centers, of their ground for cereal grains and silage. Nursery over half of the 7,600 acres are maintained as commercial operations cover just under 300 acres, and vegetable and agriculture. A large portion of the agricultural land flower operations cover approximately 200 acres. There produces commercial grains or hay and silage (800 are also many small livestock operations and commercial acres) to support local dairies (one of which is within the horse stables.
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DRAINAGE AND FLOOD PROTECTION the pumping needs for about seven months of the year. All water leaving the District is pumped, except the water Flood protection and agricultural drainage is managed by leaving through the flood gates after a flood. A fish ladder the French Slough Flood Control District, an entity that provides access to adult salmon migrating up French uses fees collected from landowners within the area to Creek in the fall and a pair of fish-friendly pumps provides maintain a system of ditches, river levees and a pump downstream access to juveniles in the spring and early station. A significant portion of the District is lower than summer. mean river levels for much of the year and extremely flat. For this reason, the levees and pump station are necessary to keep the land drained so present farming ZONING practices can occur.12 The French Slough Flood Control District is zoned Agriculture-10 Acre. This zoning designation, along The levees were built in the early 1900s and upgraded with additional protections provided by the density with help from the Soil Conservation Service (now fringe regulatory framework, make non-agricultural Natural Resources Conservation Service) in the early related development in this area difficult. Despite these 1960s, at the same time the pump station was built protections, subdivision of larger farms into smaller farms and French Slough was widened and straightened. The as well as conversion to non-agricultural uses threaten diking and levee system in the Lower Snohomish River the viability of traditional commercial agriculture in this was constructed to provide flood protection for lower area so close to the urban centers of Snohomish and level floods but not so high as to protect against water Monroe. from larger events. In 1991, members of the Snohomish River Coordinated Diking Council (Diking Districts 1-5, Drainage Districts 6 and 13, French Slough and Marshland Flood Control Districts and a few private dike Current and future impacts managers) participated in development of the Snohomish FLOODING River Comprehensive Flood Control Management Plan The Snohomish River estuary is low gradient with tidal and agreed to maintain their levees at one foot above influence extending 16 miles upriver to the confluence 9 modeled 5-year flood levels. The result of this agreement of the Skykomish and Snoqualmie Rivers near Monroe. has been that the French Slough levee overtops at Flooding in the French Slough Flood Control District is the same time as other district levees, relieving flood influenced primarily by river levels and upland runoff, pressures and the risk of breaches. In 2013, most of the although sea level rise is also projected to exacerbate dike was certified to Army Corps of Engineers standards flooding issues and impact the drainage of farmland. and enrolled in the PL84-99 program, so the federal agency will repair levees if damaged as a result of a flood. New modeling work completed for this planning The agency will also assist with the costs, permitting, effort shows strong evidence for increased frequency and design of regular levee maintenance, although this is and extent of flooding (2-, 10-, 25- and 100-year ultimately the responsibility of the District. events) with particularly impactful changes for the more frequent 2- and 10-year flood events.7 In the The land within the French Slough Flood Control District Snohomish River watershed, projections indicate that receives considerable water from the uplands. The the acreage inundated in a 2-year flood will more than waterways require frequent maintenance to clean out double, increasing from 16,946 acres to 40,134 acres sediment and grass to maintain flow. The District receives by mid-century.1 The frequency of flood events is also minimal funding from Snohomish County to compensate projected to increase. Farmers in the Lower Snohomish for upland stormwater and sediment inputs. The pump identified the 17-ft and 23-ft flood stages (at Monroe station consists of two 150 hp pumps and four 450 gauge #12150800) as critical thresholds used for risk hp pumps that move water from French Slough to the management (e.g. when levees overtop, livestock must Snohomish River, although one pump can handle most of be evacuated, structures flood, etc.). The models show
73 Agriculture Resilience Plan
that the 17-ft stage height is currently exceeded about land to subside quickly. A study of subsidence rates one day per year and is projected to be exceeded for 3 completed for this planning effort in the Lower Snohomish days per year, on average, by the 2050s.7 The 23-ft flood River floodplain indicates rates of approximately 1-6 is projected to happen two to three times as often by the inches of subsidence every 10 years in some areas, 2050s and three to four times as often by the 2080s. although there is a large amount of error associated with this estimation.11 Most flood-prone structures in the District have been raised in recent years, so while higher intensity and more frequent floods will mean more levee overtopping, the OTHER greater risk is a levee failure. A levee breach would cause Other current and projected impacts: extensive damage to farm and community infrastructure. A section of levee at the mouth of the Pilchuck River, for • Continued increases in surface water runoff coming example, has received pressure from both flood waters from upland areas cause sedimentation of drainage and sediment deposition in recent years and has needed ditches and increased field inundation. repair and fortification. • Farmers have seen an increased need for irrigation in recent years. Many farmers have not traditionally GROUNDWATER LEVELS irrigated and do not have water rights. The lack of available water rights threatens viable crop yields. Groundwater levels in the French Slough Flood Control District are projected to be impacted by sea level rise. • Economic pressures for producers are resulting in While the predicted rise in local sea level ranges greatly, subdivision of large farms and reduction of the available median values indicate an increase of 10 inches by 2050 acreage needed for current commercial farmers to be 2 and over 2 feet by 2100 (RCP 8.5 50th percentile values). viable. French Slough Flood Control District is 13 miles from the mouth of the Snohomish River, yet the low gradient of the river translates into groundwater level impacts from sea Resilience Needs level rise into a portion of the District. These increases may impact the timing of crop cultivation and hay harvest TIER ONE (HIGH PRIORITY AND IMMEDIATE) in the spring. A groundwater study completed as part of • Financial assistance for drainage system this plan calculated delays in spring cultivation based on maintenance . Increased upland stormwater runoff and these sea level rise predictions. The study found median more intense flooding as a result of climate change projected delays of 4 weeks by 2080 and 5 weeks by will increase the drainage burden of farmers in the 2100 in the downstream (western) portion of the District floodplain. New permitting requirements for increased (RCP 8.5).3 This study only looked at the impacts of sea protections for fish during ditch cleaning have also level rise on groundwater levels and did not take into resulted in higher costs to complete maintenance. account the ability of this District to actively pump water There is a need to explore ways to increase the out of the system. Increased pumping, therefore, could amount of stormwater runoff funding received from mitigate the impact of these rising groundwater levels. local jurisdictions to support ditch and waterway maintenance as well as assist with electricity costs to run the pump station. Farmers would also benefit from LAND SUBSIDENCE assistance replacing or installing drainage infrastructure Much of the land in this district was once a 4,000-acre on individual farms. scrub-shrub wetland in the lower French Creek watershed • Increased funding available for larger levee and that has since been drained for agricultural use.13 drainage infrastructure projects . Although levees and As such, approximately 2,000 acres are soils high in pumps are in good condition, a levee breach would organic matter. Cultivation and drainage of these soils mean costly repairs that would exhaust the existing has resulted in higher decomposition rates, causing the
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contingency funds available. It would help to explore approaches to increasing funding available to remove options and partnerships for developing a grant and/or development rights. loan program for larger resilience projects. • Research alternative on-farm drainage • Access to water for irrigation . Most farms do not infrastructure techniques . The District could benefit have sufficient water rights, and while many have not from funding for research and pilot projects looking at traditionally needed to irrigate, higher temperatures ways to better construct and manage drain tile or ditch and less summer precipitation has resulted in higher systems to hold water back during summer months. irrigation needs in recent years. There is a need to • Assistance with permitting for drainage system develop creative approaches to providing irrigation maintenance . Every 5 years, the District is required water to farmers. to renew their Hydraulic Project Approval permit with • Flood risk training for new landowners . New farmers the Department of Fish and Wildlife, allowing them to moving into the District could benefit greatly from maintain their drainage infrastructure. The District could training on how to minimize flood risk by accessing use assistance with this process through staff capacity flood data and predictions available through Snohomish and funding. County and by preparing for floods. • Reduce upland runoff . It would help to explore the • Improve flood warning system . Farmers have use of green stormwater infrastructure, regulatory very little time to prepare for floods and limited changes to county and city code, and/or education and flood warning information. Real-time gauges, more incentives for urban/suburban landowners to reduce sophisticated predictions, and improved notification to impervious or drainage projects on their properties. farmers are needed.
• Reduce subsidence . There is a need to explore creative approaches to reducing subsidence in areas where organic soils are decomposing, potentially through soil augmentation.
• Funding for drought resilience Best Management Practices . Existing incentive programs do not pay sufficient rates for practices that build soil health and increase the water holding capacity of soils. Funding and equipment is needed for practices such as cover cropping, no-till, compost or biochar application, and agroforestry. Developing ecosystem service markets for carbon sequestration or water quality could provide funding for these practices and increase the economic resilience of farms.
TIER TWO (LOWER PRIORITY) • Conserve existing farmland . The proximity of this floodplain reach to the cities of Snohomish and Monroe put development pressure on commercial farmland. Existing funding sources for Purchase of Development Rights (PDR) and Transfer of Development Rights (TDR) programs are insufficient to protect farmland at the landscape-scale. There is a need to pursue innovative
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Snohomish River Confluence – Tualco Valley and Vicinity
Marshland French Slough Skagit County Flood Control O Flood Control District ld Rd S District s n re o Ac d h S n o h o m i s h R o ce m n e C o u ne t y k i r a s L h lo - F s M Map Acres Rd d o ence o r o n FloDetail r W WA-9 o e R King County d 154th St SE US-2
Broadway Ave Fryelands Blvd 164th St SE W Main St Lower Skykomish
S n Ben Howard Rd E o ll h io o tt m R is d h R iv er H ig h B Snohomish r idg e Rd River Confluence WA-522
P ar ad ise La ke Rd Armoured Banks Levees and Dikes Reach Boundary
NE 198th St 0 1 Mile ±
Figure VII-12 . Map of the Snohomish River Confluence . This figures shows the boundary of the Tualco Valley and vicinity along with existing levees and revetments.
Description The agricultural area in the vicinity of the Tualco Valley agriculture. The livestock industry dominates this area, supports a thriving agricultural industry which is able with approximately 1,000 acres in hay and silage (to to take advantage of a wide floodplain with rich soils, support the five small and large-scale dairies) and yet is far enough from larger urban centers to remove 1,300 acres in pasture. Smaller acreages are dedicated some of the pressures associated with development to producing cereal grains, vegetables, and flowers. and to keep land prices low. Of the 8,800 acres in this Between 2004 and 2011, this area was the focus of area, approximately half is actively used for commercial a farmland protection effort by Snohomish County
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that resulted in more than 450 acres of farms being Local farmers have already noticed more intense and protected from future development through a Purchase of longer duration flooding than in the past. The major Development Rights program. impacts of flooding in this reach include:
• Sand and silt deposition on fields, which can result in DRAINAGE AND FLOOD PROTECTION decreased yields This area is not managed by an organized diking or flood control district. The levees are not contiguous as in the • Flood debris on fields, which requires costly clean-up Lower Snohomish, but rather provide protection against and repair flood flows and debris at strategic locations along the • Damage to structures, which results in costly repair river. The levees along with multiple shoreline armoring projects were built primarily between 1920 and 1950, • Threats to livestock, including harm to animals, largely by the Army Corps of Engineers. Individual farmers decreased milk production, or impacted milk transport maintain drainage infrastructure as well as shoreline armoring projects on their properties. • Pasture inundation, which can harm pasture grass • Bank erosion, which causes loss of farmland in limited ZONING locations The agricultural land in this reach is primarily zoned Agriculture-10 Acre. The density fringe regulatory GROUNDWATER LEVELS framework protections that exist in downstream Groundwater levels and saltwater intrusion in the floodplain reaches do not extend into this area, although Snohomish Confluence area are not expected to be much of the area is designated as floodway. The impacted by rising sea levels due to the large distance floodway designation carries significant restrictions on from the Puget Sound.3 Groundwater levels may be development (SCC 30.65.220). For this reason, loss of impacted by increased riverine flooding or upland commercial farmland to development or subdivision is not stormwater runoff, although these effects are predicted to a major threat. be shorter in duration than the sustained impacts of sea level rise downriver.
Current and future impacts RIVER CHANNEL AGGRADATION FLOODING Local farmers report that they have noticed channel The Snohomish River estuary is low gradient, with tidal aggradation in this reach of the Snohomish and influence extending 16 miles upriver to the confluence Skykomish Rivers. In a study of aggradation completed of the Skykomish and Snoqualmie Rivers near Monroe. as part of this plan, channel aggradation was identified While there is a muted tidal signal in and around the between river miles 12 and 17 (from the City of Tualco Valley, flooding is largely dependent on river flows Snohomish just past the confluence of the Skykomish and not tides or sea level. and Snoqualmie Rivers) between 2001 and 2017.11 The overall capacity of the channel to carry flood waters, New modeling work completed for this planning effort however, was not reduced, likely due to channel shows strong evidence for increased frequency and widening.11 This study, therefore, concluded that changes extent of flooding (2-, 10-, 25- and 100-year events) in flooding on agricultural land are not a result of river with particularly impactful changes for the more frequent channel aggradation. 2- and 10-year flood events.7 In the Snohomish River watershed, projections indicate that the acreage inundated in a 2-year flood will more than double, increasing from 16,946 acres to 40,134 acres by mid-century.1 77 Agriculture Resilience Plan
OTHER • Funding for drought resilience Best Management Practices . Existing incentive programs do not pay Other current and projected impacts: sufficient rates for practices that build soil health and increase the water holding capacity of soils. Funding • Continued increases in surface water drainage coming and equipment is needed for practices such as cover from upland areas cause sedimentation of drainage cropping, no-till, compost or biochar application, and ditches and increased field inundation. Permitting agroforestry. Developing ecosystem service markets constraints also make it difficult to clean these for carbon sequestration or water quality could provide waterways in a timely manner. funding for these practices and increase the economic • Farmers have seen an increased need for irrigation resilience of farms. in recent years. Many farmers have not traditionally irrigated and do not have water rights. Lack of available TIER TWO (LOWER PRIORITY) water rights will threaten viable crop yields. • Flood risk training for new landowners . New farmers • Economic pressures for producers are resulting in moving into the District could benefit greatly from subdivision of large farms and reduction of the available training on how to minimize flood risk by accessing acreage needed for current commercial farmers to be flood data and predictions available through Snohomish viable. County and by preparing for floods.
• Improve flood warning system . Farmers have very little time to prepare for floods and limited Resilience Needs flood warning information. Real-time gauges, more TIER ONE (HIGH PRIORITY AND IMMEDIATE) sophisticated predictions, and improved notification to • Access to water for irrigation . Most farms do not farmers are needed. have sufficient water rights and while many have not • Research alternative on-farm drainage traditionally needed to irrigate, higher temperatures infrastructure techniques . The District could benefit and less summer precipitation has resulted in higher from funding for research and pilot projects looking at irrigation needs in recent years. There is a need to ways to better construct and manage drain tile or ditch develop creative approaches to providing irrigation systems to hold water back during summer months. water to farmers. • Reduce upland runoff . Explore the use of green • Financial assistance for drainage system stormwater infrastructure, regulatory changes to county maintenance . Increased upland stormwater runoff and code, and/or education and incentives for urban/ more intense flooding as a result of climate change suburban landowners to reduce impervious or drainage will increase the drainage burden of farmers in the projects on their properties. floodplain. There is a need to explore ways to increase funding available to include compensation from upland stormwater runoff impacts to pay for ditch and waterway maintenance.
• Drainage infrastructure improvements . To improve existing drainage and increase resilience to future groundwater and flooding impacts, several types of actions are recommended. Both on-farm drainage improvements (e.g. tile systems) and landscape-scale drainage projects along waterways (e.g. culvert replacements and channel excavation) will increase resilience to changes in hydrology.
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Lower Skykomish River
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Figure VII-13 . Map of Lower Skykomish River floodplain . This figure shows the boundary of the Lower Skykomish River, along with existing levees and revetments.
Description The floodplain narrows above the confluence of the DRAINAGE AND FLOOD PROTECTION Skykomish and Snoqualmie Rivers, but commercial This area is not managed by an organized diking or flood agriculture remains viable up the Skykomish River control district. Existing levees are not contiguous as for approximately fifteen additional miles. The Lower in the Lower Snohomish, but rather provide protection Skykomish area represents approximately 1,700 acres against flood flows and debris at strategic locations of commercial agricultural land predominately in feed along the river. The levees along with multiple shoreline and forage production to support the livestock industry armoring projects were built primarily between 1920 and and local dairies. In addition, smaller acreages support 1960, largely by the Army Corps of Engineers. Individual production of vegetables, cereal grains and nursery farmers maintain drainage infrastructure as well as plants. shoreline armoring projects on their properties.
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ZONING Resilience Needs The agricultural land in this reach is primarily zoned Agriculture-10 Acre. The density fringe regulatory TIER ONE (HIGH PRIORITY AND IMMEDIATE) framework protections that exist in downstream • Protect farmland from riverbank erosion . Numerous floodplain reaches do not extend into this area, although bank stabilization projects were put in place in the much of the area is designated as floodway. The mid-1900s. Several of these have started to erode, floodway designation carries significant restrictions on but new permit requirements have made it difficult development (SCC 30.65.220). For this reason, as well as and costly for farmers to repair them or construct new the large distance from urban areas, loss of commercial projects. farmland to development or subdivision is not a major threat.
Current and future impacts FLOODING New modeling work completed for this planning effort shows strong evidence for increased frequency and extent of flooding (2-, 10-, 25- and 100-year events) with particularly impactful changes for the more frequent 2- and 10-year flood events).7 In the Snohomish River watershed, projections indicate that the acreage inundated in a 2-year flood will more than double, increasing from 16,946 acres to 40,134 acres by mid-century.1 In the Lower Skykomish River floodplain, the current modeled 2-year event does not leave the river channel, yet by the 2050’s it is expected to inundate much of the floodplain. The frequency of flood events is also projected to increase.
The largest projected impact of these higher intensity floods will be loss of farmland to eroding riverbanks. Much of this reach has been armored with rip rap along banks, locking the channel into place to reduce channel migration. This has had the added effect of causing channel incision in some areas, further exacerbating bank erosion by disconnecting the river from the floodplain during larger floods.
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1 Fathom. 2019, Puget Sound Hazard Mapping Report.
2 Miller, I.M., Morgan, H., Mauger, G., Newton, T., Weldon, R., Schmidt, D., Welch, M., Grossman, E. 2018. Projected Sea Level Rise for Washington State – A 2018 Assessment. A collaboration of Washington Sea Grant, University of Washington Climate Impacts Group, University of Oregon, University of Washington, and US Geological Survey. Prepared for the Washington Coastal Resilience Project.
3 Cardno, 2019. Climate impacts to groundwater in the Lower Snohomish and Stillaguamish River basins. Report produced for the Snohomish Conservation District. Lake Stevens, WA.
4 Northwest Hydraulic Consultants (NHC), 2014. Douglas Creek and vicinity hydrologic and hydraulic modeling. Report prepared for Snohomish County. Everett, WA.
5 Snohomish County Public Works Surface Water Management (SWM), 2015. Douglas Creek and vicinity basin characterization report. Everett, WA.
6 Snohomish County Surface Water Management (SWM) and the SLS Executive Committee, 2018. Mainstem Stillaguamish River Reach-scale Plan. Snohomish County Department of Public Works and the Executive Committee of the Sustainable Lands Strategy. Everett, Washington.
7 Mauger, G.S., S.-Y. Lee, and J.S. Won. 2019, Mapping the future of flood risk for the Stillaguamish and Snohomish Rivers. Report prepared for the Snohomish Conservation District. Climate Impacts Group, University of Washington, Seattle.
8 Cardno, 2019. Technical Memo: Stillaguamish Flood Control District subsidence and sedimentation study. Report produced for the Snohomish Conservation District. Lake Stevens, WA.
9 Snohomish County Public Works Surface Water Management (SWM), 1991. Snohomish River Comprehensive Flood Control Management Plan. Everett, WA.
10 Bartelheimer, D., 2019. Personal communication with Cindy Dittbrenner (Snohomish Conservation District). October 20, 2019.
11 Cardno, 2019. Technical Memo: Lower Snohomish River District subsidence and sedimentation study. Report produced for the Snohomish Conservation District. Lake Stevens, WA.
12 Wheeler, Neil, 2019. Personal communication with Cindy Dittbrenner (Snohomish Conservation District). August 27, 2019.
13 Snohomish County, 2004. French Creek Watershed Management Plan. Everett, WA.
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Chapter VIII Next Steps
“We grow produce for people now but we take care of the land for our children. We want them to grow up in a healthy world.”
Anna Caruso, Caruso Farms, Photovoice 2017
This Agriculture Resilience Plan for Snohomish County While there are many economic, regulatory and policy will help ensure the viability of our farmlands into the factors influencing the success of our local farms, the future. The next step is to continue to work together as an actions prescribed in this Plan are aimed at ensuring the agricultural community to implement the actions included viability, protection, and resilience of the land itself. These in this Plan. The Steering Committee recognizes that include both county-wide actions and those specific these actions cannot be achieved without collaboration to different reaches of the floodplain. The actions are and partnership. The needs represented in this plan, diverse and include policy changes, re-allocation of tax therefore, are a starting point for collaborative thinking dollars, landscape-scale project implementation, on-farm with partners, communities and government bodies about resource needs, and continuing research and education. how we manage our land and our natural resources in a time of changes and uncertainty.
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Through partnerships developed as part of the A working appendix to this Plan will be the Project List Sustainable Lands Strategy (SLS), the farming that is continually refined and adapted to reflect the community in Snohomish County hopes to find mutually changing needs of the agricultural landscape and the beneficial solutions to managing our natural resources collaborative process facilitated by the Integration Team for agricultural resilience, salmon habitat recovery, and to develop innovative, landscape-scale solutions to flood protection. The newly launched Integration Team is community resilience. an SLS initiative that brings partners together to develop packages of projects and actions that support these multiple interests as well as procure funding to support project implementation. We hope that both the technical information provided through this planning effort as well as the identification of prioritized agricultural needs will help further this collaborative approach to land management.
“This is farmer led. This is not a plan that’s going to sit on a shelf somewhere. It’s a plan that’s going to lead to action to help real farmers with real concerns.”
Karen Wolden-Fuentes, Hazel Blue Acres Farm
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