The Betsie Valley Trail floods in June 2019. Photo by Kelly Thayer.
Editor’s note: While world leaders gather through November 12 in Glasgow, Scotland, at the United Nation’s COP26 climate change conference, FLOW Founder Jim Olson in this blog calls for a new approach to watershed and land use planning and zoning in the Great Lakes Basin that respects the increasing variability of water levels.
By Jim Olson
Whether it’s extreme drought or heavy precipitation and flooding from climate change events, it is indisputable that the range between all-time high and all-time low water flows and levels in the Great Lakes watershed has changed dramatically, and will become only more extreme.
Because the change is permanent for the foreseeable future, current assumptions and data about water levels, wetland maps, and floodplain maps are obsolete. Climate change is not only straining infrastructure for water, sewer, storm runoff, roads, bridges, dams, breakwalls, harbors, airports, and more, but it also is transforming natural areas at the land-water interface. Lowland not previously mapped is changing into floodplains or even wetlands, floodplains are changing to wetlands, and wetlands are fast changing to emergent and inundated wetlands.
Yet we have not mapped what is happening and what is to come based on climate change forecasts in each area or region. We haven’t even gathered and incorporated the data on rapidly changing conditions that we need to map.
It is essential and long overdue, at this point, and a costly failure in our law and public policy, not to measure and map these changes, and adopt new or amended regulations that prevent the filling or diminishment of wetlands and floodplain-wetlands, and the new floodplains.
The sooner, the better.
We will save billions of taxpayer dollars in damages averted, and trillions of dollars nationwide, and at the same time prevent or mitigate recurring damage to our health, communities, infrastructure, and economy from the increasing intensity and frequency of climate-fueled extreme weather events. Once the mapping is completed, these areas must be jealously guarded as the backbone of our natural and built systems, for nature-based green infrastructure to provide ecosystem services that include drainage, flood control, water recharge, but also habitat and land uses that underpin our homes, communities, jobs, and economy.
In her acclaimed book Replenish (Island Press, 2017), leading global water policy expert Sandra Postel describes in Chapter 4, titled “Make Room for Floods,” the dramatic increase in the evaporation rate of 6-7% for every degree Celsius of increase in temperature. Some scientists refer to this increased rate of evaporation as “rivers in the sky,” ready to drop the next catastrophic harm somewhere in the world. Twenty-year, 50-year, or even 100-year weather events are becoming far more frequent, and have not been incorporated into our planning, land use, and development tools and regulations.
Author Postel describes the historic flood of 1927 in the Mississippi River basin, when the river breached or overtopped levees in 145 locations, inundated 16 million acres of cities and farms, and displaced 700,000 people from their homes, some for weeks or months. In the disaster’s aftermath, the Flood Control Act of 1928 directed the U.S. Army Corps to stop piecemeal management of floods in the Mississippi River basin and to adopt a coordinated system. With levees remaining the system’s backbone, the act called for something new: the creation of “floodways”—areas where some water from a raging Mississippi could exit the main channel and flow into a designated area on its former floodplain. In that way, some pressure would be taken off the levees, reducing the risks of a breach.
Because the federal government under the floodway project was persuaded to invest $14 billion to purchase farming and residential property rights in floodplains, upgrade levees, and develop other components of the system, when a record flood in 2011 poured into the restored floodways, the damages were confined to $2.8 billion, or about one percent of the $234 billion in damages to farming, cities, and infrastructure in the last major storm before the floodway project was started.
With climate change worsening and no major shift by nations and states in sight despite the hopeful changes that might come from the ongoing COP26 climate conference, it is up to each nation, state and community, and professional planners, engineers, and developers to step up their efforts to conduct and complete the needed changes in collecting data and mapping. This will allow us to know where and when to expect the expanded and shifting range of low- and high-water or flooding conditions in every watershed. Then state and local planners and zoning officials must reevaluate land use plans, zoning ordinances, and stormwater, drainage, and sedimentation control standards and ordinances.
As an emergency measure before this mapping and these much needed changes are implemented, states and local communities should impose a moratorium on any further filling, dredging, clearing, or altering of any wetlands and floodplains. Exceptions could be made where there are no adverse impacts from a proposed project when taking into account climate change effects, no other feasible and prudent alternatives exist, and the proposed activity is necessary for public health, safety, and general welfare.
If we invest in these emergency measures, collecting the data and remapping our natural areas for drainage, flood control, and water recharge, we will be more nimble and resilient before the next major weather event strikes. And it will.