Goal: Increase the resilience of the built environment and protect natural resources
Climate adaptation is about developing and implementing strategies to help human and natural systems cope with and become more resilient to the impacts of climate change.
The county needs to plan for and respond to increased pressure on natural resources and the built environment, including building sites, roads, and other infrastructure, from impacts such as increased rainfall, extreme weather, and freeze/thaw cycles.
There are also many opportunities to use green and natural infrastructure to manage stormwater, improve water quality, decrease the urban heat island, and sequester carbon.
Protecting and enhancing our natural areas will provide habitat for native plants and wildlife, increase wellbeing, and make our communities more resilient.
Buildings and transportation infrastructure
Transportation infrastructure is currently designed to handle a broad range of impacts based on historic climate records and familiar seasonal variations. Preparing for climate change and extreme weather events using projections of increased precipitation and heavier rainfall events is critical to protecting the integrity of the transportation system and the sound investment of taxpayer dollars.
While most county roads are kept passable with a stormwater pipe network, these pipes were designed to old precipitation projections and may not adequately keep roads passable given mid-century precipitation projections.
In addition, Minnesota is experiencing warmer winters and an increase in freeze/thaw events, which negatively impact pavement systems. Generally speaking, more freeze/thaw cycles will accelerate infrastructure deterioration, especially for older pavements that already have many distresses and cracks in the surface and places where water will impact buildings, facades, sidewalks, and plazas.
Objective: Climate risks and impacts to county buildings and infrastructure are assessed and mitigated
- Strategy: Reassess policies, design standards, and maintenance practices for county buildings and infrastructure project
Increased stormwater and localized flooding
Surface water impacts are determined by how much and how quickly precipitation falls and by the ability of soils to infiltrate water or the capability of storm water conveyance systems to drain it away. Increased precipitation also increases groundwater recharge, which in many cases results in a rise in local water tables. This can create groundwater flooding, which is already occurring in several locations in Hennepin County.
The increased flooding poses risks to numerous properties, many of which may not have flood insurance because they are located outside of the mapped 100-year floodplain. While the acute risks posed by surface flooding from heavy rains are potentially covered, the longer-term impacts of increased precipitation such as rising water table levels and the expansion of wetlands and shorelines can jeopardize local infrastructure, private wells and sewage treatment systems, cause flooded basements, and create water-quality impacts.
Objective: Risks and impacts from increased precipitation, flooding, and landslides are reduced
- Strategy: Reassess policies and practices to manage increased stormwater volumes
- Strategy: Manage the increased risk of landslides due to increased rainfall
- Strategy: Coordinate regional stormwater resiliency efforts with public entity partners
Green infrastructure and resilience in the built environment
Green Infrastructure refers to ecological systems, both natural and engineered, that act as living infrastructure. Examples include rain gardens, bio-swales, and green roofs. These systems restore some of the natural processes required to manage water and create healthier urban environments.
Building and maintaining green infrastructure to manage stormwater in flood-prone areas, especially on county-owned property, can protect surrounding properties, create green spaces, and make the community more resilient to climate change.
The county has developed green infrastructure through programs including transit-oriented development, Environmental Response Fund for the clean up of contaminated sites, natural resources grants, and forestry.
Objective: The county employs green and natural infrastructure, including trees, plants, and soil, to build resiliency, especially in areas at higher risks for localized flooding and extreme heat
- Strategy: Reassess policies and practices to ensure capacity to design, implement, and maintain green infrastructure
- Strategy: Use county investments to increase resilience in the built environment
- Strategy: Plant, diversify, and maintain trees throughout Hennepin County and increase the resiliency of the county’s community forest
Natural areas and agricultural lands
Hennepin County has an abundance of natural areas and diverse landscapes that provide critical habitat for wildlife, protect water quality, offer recreational opportunities, and serve as the foundation for the region’s environmental wellbeing, economic prosperity, and collective quality of life.
As the Soil and Water Conservation District for Hennepin County, the county is responsible for providing technical and financial assistance to landowners to help manage natural resources, protect soil, preserve habitats, and improve water quality. The county also enforces wetland regulations, establishes conservation easements, protects natural areas, maintains natural resources data, and provides technical assistance to local governments.
Native wildlife and plants are extremely sensitive to climate change impacts. Climate change will further disrupt our ecosystems, which are already impacted by invasive species, population growth, and development. Healthy ecosystems play a vital role not only in the health of plants and animals, but of people, too.
The trend toward a wetter climate has already added uncertainty and increased the challenge of producing food in a rapidly developing county. Working with residents to preserve open space and improve agricultural practices represent some of the best opportunities to sequester carbon, manage increased precipitation, connect habitats, and improve access to nutritious, locally produced food.
Objective: Natural areas and open spaces are functional and diverse
- Strategy: Plan for and mitigate anticipated ecosystem and open space impacts