River Basins, Rainstorms & Rising Groundwater: Flooding in the Tri-County Region
Every year, people across the United States and around the world experience various types of flooding events. Between 1900 and 2016, more people had their lives disrupted by flooding than any other type of natural disaster. During the Midwest Floods of June 2008 alone, over 11 million people were impacted across the U.S. due to a combination of factors including heavy winter snow, extreme soil moisture, and heavy summer rains. With an increase in flooding events in recent years, it is important for individuals, community leaders, and policy makers to understand what causes different types of flooding so they can make informed decisions. Knowing how flooding events can affect our water resources helps us all work together to effectively plan for potential future floods and keep residents safe.
One of the most important things to understand about flooding is its unique role within the water cycle. The water cycle has several different phases that help to move water between the atmosphere, land, surface water (such as rivers or lakes), groundwater, and the oceans. Most flooding is brought about by one phase of this natural process becoming overwhelmed due to fluctuations in the water cycle (such as changing weather patterns), resulting in the collection of above-average amounts of water in a certain location. This can occur along shorelines, riverbanks, flat areas of land, and in urban environments with a high concentration of non-porous paved surfaces, all of which can experience different types of flooding. With our variety of ecosystems, Michigan is no exception; here we can experience flash flooding, groundwater or stormwater flooding, river flooding, coastal flooding along the Great Lakes, ice or debris jams, snowmelt flooding, and even dam breaks or levee failure flooding.
Historical Flooding Events in the Tri-County Region
Within Clinton, Eaton, and Ingham counties, there have been several major flooding events in our history. One of the most notable was the Lansing Area Flood of 1975, which occurred when a seven-hour rainstorm discharged more than four inches of water on top of snow that had already saturated the soil.35 This event caused over $50 million in damage and flooded over 4,600 homes. During the Grand River Flood of 2013, high river and tributary water levels closed over 300 roads and flooded more than 1,200 homes in communities all the way from Grand Rapids to Lansing. This flood set several records at the time, with estimated damages well beyond $43 million. More recently, Michigan State University and neighborhoods along the Red Cedar and Grand Rivers experienced major flooding in early 2018. This event impacted over 200 homes, 24 business, dozens of roads, and several parks and bridges in the area.
Similar to snowmelt flooding, groundwater flooding can occur as a result of frequent, sustained rainfall. This rainfall leads to an excessively fast recharge of local groundwater levels, causing the water table to rise above the land surface. Stormwater flooding occurs under the same conditions as groundwater flooding, but is caused specifically by a backup of the storm drain system as the ground becomes fully saturated. When there is too much water for the storm drains to redirect it properly, the water will flood impermeable surfaces, like paved roads or sidewalks, and can even overflow into yards, parks, and other pervious surfaces. Typically, stormwater flooding can recede quickly over a few days, or even just a few hours, once the rain stops and the water is able to drain. Groundwater flooding can take much longer to recede, as all the water in the area’s underground aquifer must find somewhere to go until the water table returns to its natural level below ground. The rapid snowmelt flooding combined with the already-overwhelmed stormwater and groundwater systems are some of the many factors that are thought to have contributed to the significant damage caused by the Lansing Area Flood of 1975.
Another type of flooding, referred to as riverine flooding, was the cause of the Grand River Flood of 2013 and the flooding experienced by the Lansing-East Lansing area in 2018. While fluctuations in a river’s water level are normal throughout the year, riverine flooding occurs when a river receives too much water at once, causing water levels to quickly rise and spill over the banks of its channel. These flood waters then enter the region’s floodplain, the land surrounding a river that would be most likely to flood with water from a 100-year flooding event. We continue to see this type of flooding impact our region due to both Lansing and East Lansing metropolitan areas’ proximity to the Red Cedar and Grand rivers. The 2018 riverine flooding event was felt to be the worst flood in Lansing since 1975 and affected more than seven different neighborhoods in the city.
Flooding in Our Natural & Built Environments
In addition to causing extensive damage to homes and communities, flooding can have substantial impacts on our mobility, economy, and infrastructure. During the 2018 flood, the tri-county region saw over a dozen streets and two bridges closed due to high waters. As a result, traffic and public transportation systems had to be rerouted, impacting both commercial and personal travel. The floodwaters also led several local businesses to close until waters receded and damage could be repaired, resulting in lost wages for workers and serious financial impacts for owners.
Though flooding can bring significant damage to our economic, natural, and built environments, in some cases it can be considered beneficial for our water resources. For example, ecological habitats within floodplains — like wetlands, forests, and more — depend on the occasional flooding of riverbanks so sediment and nutrients suspended in the water can enrich the area’s soils and plants. Before modern fertilizers, farmers took advantage of this to improve their soils for agricultural purposes. In today’s modern society, there are more urban areas with many different types of non-porous surfaces that can prohibit or slow down this natural reabsorption of floodwaters. This makes it much more difficult to see the benefits of flooding, or to appreciate the elements of our environment that rely heavily on this component of the water cycle. Groundwater, though underground and out of sight, is a primary source of drinking water for many communities and an important natural resource that can be impacted by flooding. Though groundwater recharge occurs naturally, certain states such as California, use floodwaters to recharge underground aquifers; this is especially helpful in preparation for potential future droughts, which can impact groundwater levels of their local aquifers. Additionally, natural controls on flooding, such as maintaining healthy wetlands, can help to mitigate damage while also maintaining water quality by filtering nutrients and impurities from runoff, processing organic waste, and moderating temperature fluctuations. Riverine flooding also helps to promote the infiltration of water into the ground to benefit surrounding groundwater-fed outlets like rivers, springs, and lakes.
Floodwater Well Damage & How to Handle It
As is evident from the damage caused by historic floods in our region, the natural benefits of flooding events are not without severe cost to our built environments and the resources we rely on. These events have caused and will continue to inflict widespread damage to homes, roadways, bridges, and all types of built infrastructure – including drinking water systems. Fortunately, much of our public drinking water supply structure is located deep below ground and is not as susceptible to damage during flooding events. However, flooding can have a substantial impact on individual homeowners’ private drinking wells and septic systems, which may lead to the contamination of water supplies. If your property depends on a private well and has been partially or fully flooded, there are a few steps you can take to protect yourself and your family.
First, consider your home’s waste-removal system. If you have a septic system, it’s important that you do not use it while the ground is still saturated with water from the flood, as this prevents your system from filtering the wastewater through the drainage field. If you use your septic system while the ground is still saturated, you risk flooding your yard or even your home with septic waste. Additionally, this oversaturation of the ground or moving flood waters could have caused damage to your system. To ensure your septic system is in working order, contact a local plumber or septic service before use. They will be able to determine if there is any risk of sewage getting backed up into your yard, which can lead to well contamination.
Aside from potential contamination by a faulty septic system, there is also risk of your well itself being damaged by floodwaters. Moving water or high winds can carry large debris that can loosen well hardware, dislodge well construction, or distort casings. It is highly recommended that all wells less than 50 feet deep or over ten years old are inspected by a licensed official. Though damage may not be immediately noticeable or visible aboveground, these wells are more likely to become compromised or even collapse. An electrician should also inspect the well pump and its wiring to ensure the flood has not caused any shorts or breaks in the system. It is important that you take caution when attempting to visually inspect your own well; avoid wading in deep water, as rubber boots and gloves may not be enough to prevent electrical shock from damaged wiring.
Finally, if your well was not tightly capped, or you notice that the cap has been dislodged, it’s possible that sediment, debris, or floodwater could have contaminated it. Work with your local health department to get your well water tested before using it for drinking, cooking, and cleaning. For a full list of tips, precautions, and steps to take during an emergency or natural disaster, check out this fact sheet about the potential impacts of emergencies and disasters on your well.
Regardless of its cause, flooding is (and will only continue to be!) a regularly occurring natural phenomenon. While it may be an inevitable part of our water cycle, planning appropriately to mitigate or avoid flood damage to our built environments will ultimately allow us to take advantage of flooding’s natural benefits, like recharging aquifers and providing soil with nutrients. Encouraging communities to consider their groundwater resources when planning for future flooding events helps keep our drinking water safe, and is one step we can all take toward responsibly managing the impacts of flooding.