The following information was prepared for the Wisconsin Land and Water Conference (2019) with a regional focus. These resources, tools and tips can help watershed planners prepare for and adapt to extreme weather through the strategic consideration of wetlands, and forests. A pdf of this information is found at the bottom of the page.
Whatever your goals and values are for your watershed, the time is now to act and to reduce risks from extreme precipitation events. Forests and wetlands control water flow in your watershed, planning that includes natural features can reduce erosion, sedimentation and flood hazards to downstream infrastructure.
- Contact us for more info on these resources. contact Danielle Shannon or Kyle Magyera (Wisconsin Wetlands Association).
Natural infrastructure can reduce flood and erosion risks
Wetlands and forests reduce “flashy” pulses of water by capturing, storing, and allowing for infiltration of snowmelt and rainwater. When wetland and forest storage decreases, the energy of water flow can increase, causing even more erosion downstream. It’s a strong negative feedback loop that renders the natural and built environments of the area less capable of handling rain and snowmelt with each passing storm.
Flash floods, and seasonal flooding events can trigger catastrophic disturbances in forest ecosystems when floodwaters exceed the ability of a culvert to pass water (known as the ‘hydraulic capacity’ of the structure). When culverts or stream structures are overtopped or plugged by woody debris (like sticks and branches), this can lead to soil disturbances and streambank erosion that often deliver large volumes of sediment downstream. Flood events caused by undersized or poorly designed stream-crossings can impart major damage to wildlife habitat and adjacent properties. Stream-crossings have a lower risk of failure if designed appropriately for the stream, and with consideration of current and future regional climate conditions. Careful evaluation of structure size considering all of the factors that influence potential flood-risk can minimize future risks. Read more on this topic.
- Tips to consider when adapting systems to increased erosion and sedimentation – Protect vegetated floodplains and upstream areas at risk of gullying or headcutting and manage these areas to slow the flow! Diagnose “pinch points” that can channelize flow and disrupt floodplain access, this may be attributed to infrastructure that is aging, undersized or misaligned. Find ways to increase soil-water storage in headwaters, along streams and in floodplain areas by conserving forests and wetlands that promote deep rooted soils and infiltration.
- Helpful Tools: Consider soil types when planning activities, particularly soils susceptible to erosion. The NRCS “Fragile Soils” index can help decipher soils vulnerable to degradation with a high susceptibility to erosion. Use NRCS Web Soil Survey tool to access the data and maps.
- Tips to consider when adapting systems to more storm runoff volume and increased intensity – Plan ecosystem restorations to restore the functional hydrology at a watershed-scale. Plans that increase soil-water storage, reconnect upstream hydrology and connections to floodplains can increase the capacity of watersheds to route and absorb large volumes of water that may reduce stress on downstream infrastructure. Additionally, infrastructure can be built to accommodate and endure changing hydrology. Designing to accommodate changing hydrology may help to alleviate the long-term costs associated to maintenance, like repeated replacements and repairs for undersized or structures that fail after large rain or flood events. With precipitation inputs on the rise, the likelihood of infrastructure blowout and failure for inadequately designed structures increases over time. Examples include: using floodplain culverts, staged-release culverts, arched culverts, bridges, spillways and intentional dips in roads, etc. Check out the US Forest Service Stream Simulation tool for when designing infrastructure to match local stream characteristics.
- Case studies
The region's forests and plant communities will be affected by a changing climate during this century,
but individual tree and plant species will respond uniquely to climate change, depending on their particular ecological tolerances and location. These resources summarize general climate change projections for tree species across several large landscapes in Wisconsin.
- Tips to consider: Consider tree and wetland natural community's vulnerability to a warmer, wetter future in watershed planning and when selecting species for planting. Evaluate headwater and riparian forest health and species compositions, and take into consideration site specific characteristics that may challenge growth or regeneration (such as longer periods of inundation in floodplains) or forest pests and invasive plants. Reduce impacts of roads to forest areas.
- Lists of projected future habitat suitability for individual tree species
- Forest ecosystem vulnerability assessment for Wisconsin
- Tool to assess projected changes in plant Heat and Hardiness Zones
- Keep an eye out for invasive species – where are they now?
Learn how wetlands reduce flood hazards
Read the Wisconsin Wetlands Report “Exploring the Relationship between Wetlands and Flood Hazards in the Lake Superior Basin”
- Tools and data to gauge wetland losses – The Nature Conservancy "wetlands by design" tool
- Evaluate stream stability and fluvial erosion hazards in vulnerability assessments
- Contact Wisconsin Wetlands Association to better understand available grant opportunities
Assessing change: Climate tools and resources:
- Projected climate impacts for your area
- NOAA State Climate Summaries (observed and projected changes)
- Historical climate data – state, county, city
- Synthesis of science: Forests and Water impacts
- Learn Climate 101 basics with these free education modules
Adaptation planning tools - www.AdaptationWorkbook.org
The Adaptation Workbook is a structured process to consider the potential effects of climate change and design land management and conservation actions that can help prepare for changing conditions. The process is completely flexible to accommodate a wide variety of geographic locations, ownership types, ecosystems and land uses, management goals, and project sizes. Find more information on the Adaptation Workbook.