Land use planning involves the management and modification of the natural environment into built environments, such as villages, development of residential and commercial areas, roads and other infrastructure. Land use planning plays a central role in reducing flooding and mitigating damages. As populations have grown, and impervious surfaces and compacted/turf covered land has increased, the challenge for land planning policies that increase community resilience in terms of flood prevention, stormwater capture, and sufficient clean water quality have moved toward the forefront for successful land planning strategies. In older villages and towns, created before there was more understanding of the role of land forms and the limitations of human control over natural resources, there was building over springs and draining flood plains for building. Recent assessments of Lake County project that 9% of its lands are subject to flooding within the next 30 years. For Cook County, the number is 23%. (From the First Street Foundation’s first national flood risk assessment study)
While we have good rainfall currently, the area had droughts in 2005 and 2012. This can be expensive for populations dependent on well water, often requiring additional drilling with no guarantee of success. If our communities can’t get their stormwater runoff back into the ground, it just heads downstream to the Fox River, and ultimately to the Gulf of Mexico. It would be much better to keep it here, draining to our aquifers and allow our local communities to use it.
“Why anyone should have picked a site for a village with such topography is not known and few seem to understand. It was up hill and down, picturesque for the future, and conducive to good drainage in most places, but was full of ponds, creeks and sloughs.”
Topography chapter from Arnett C. Lines, A History of Barrington, IL Available online from the Barrington Area Library under local history.
The Flint Creek Watershed drains 36.5 square miles of what was and still largely consists of wetlands. Local topography is a result of the Lake Michigan Lobe of the last glacial retreat, some 12,000 to 14,000 years ago. The glacier deposited soil made up mainly of sand and gravel, with some clay. Spring Creek is similar, but with more sand and gravel soils. The Spring Creek Watershed includes lands that are critical for aquifer recharge for Barrington Area Council of Government (BACOG) communities.
Early farmers straightened the both creek’s curves, moved them to the edges of their fields, and used drain tiles to control the areas of ponding. Today, our villages use storm drains to collect and move water, generally emptying it back into our creeks.
Flint Creek averages only 15 to 30 feet wide, and one foot deep. During floods, those figures can triple. During years with heavy rains, as in 2007, one of the worst on record, our creeks can see significant erosion, sometimes even changing its channel in places, and frequent debris jams which can make flooding worse.
Silt is a major problem, both from flooding runoff and erosion. Phosphates are also a problem, both from fertilizer and from minerals in the native soil. Excess nutrients cause algal growth and can reduce the dissolved oxygen in water, necessary for critters at the bottom of the food chain for good fishing.
As humans increasingly alter and develop what had been areas where rains had benignly collected, runoff increases, especially through decreasing the capability of the soil and ground cover to capture and infiltrate the precipitation.
Environmental degradation coupled with uncontrolled suburban and urban development in risky areas – such as historical flood plains – leads to an increased vulnerability to catastrophic events. Those areas can experience relatively fast saturation events, which slow rainwater infiltration.
Ideally, appropriate land planning seeks to keep as much rainwater retained where it falls. Then flood peaks can be reduced and shortened. Planting long rooted native plants can help infiltration. Sound planning and regulation of land use can limit flood damage potential in flood risk areas.
Sometimes relocation is the answer. The Federal Emergency Management Agency has funds for the purchase of homes that have been flooded, and have a high probability of flooding again.
Flooding any structure can be very damaging. It may not seem like much, but even an inch of flood waters on the first floor of a structure can cause major damage to drywall, exposed insulation, wallpaper, wood floors and carpets, not to mention possible mold growth. At 2 feet, insulated appliances, electrical outlets, furnace, HVAC systems, and vehicles are affected. Yard damage can include septic issues and contaminated wells.
Defensive measures include:
– Protecting flood plains from development;
– Enforcing building codes, especially those pertaining to adequate drainage;
– Maintaining and improving stormwater drainage systems
– Restoring and protecting ecosystems and creating more green space to improve water retention;
– Rain gardens, bioswales and permeable pavements that collect rainwater, allowing it to be absorbed.
There is a new tool that aims to make flood risk more transparent developed by First Street Foundation. It makes it easy to find a property’s risk of flooding and to understand how the risk of flooding is changing because of a changing environment. It is free.