A Watershed Moment

Climate Change Considerations for Riverfront Developments

Last month marked the wettest February in central Indiana in 125 years and the fifth wettest one on record. While the effects of climate change may not be as noticeable to us Midwesterners as they are to our friends in the coastal areas, statistics like these—and data from our waterways—tell a significant story.

According to Indiana’s Past & Future Climate: A Report from the Indiana Climate Change Impacts Assessment, average annual precipitation has increased 5.6 inches since 1895, and more rain is falling in heavy downpours. (See Figure 1 for an example).

Figure 1: Annual rainfall depth trends in Northeast Indiana.

This increased precipitation, particularly the heavy rain events, increases the risk of flooding and threatens the stability of our Indiana waterways. Data gleaned from US Geological Survey (USGS) streamflow gaging stations confirms an increase in stream flows as well as flood stages in most of Indiana streams. (See Figure 2 for an example).

Figure 2: Peak annual flow trends along the Kankakee River in Shelby, Indiana.

Waterways—and the land that surrounds them—are important community resources that have a natural appeal and hold the opportunity to create a sense of place. In recognition of that, many cities and towns across Indiana are implementing riverfront developments, some of which Christopher B. Burke Engineering, LLC (Burke) is grateful to be working on.

According to Burke’s Vice President and Principal Engineer, Siavash Beik, and Burke’s Director of Planning, Sheila McKinley, creating safe, sustainable, and resilient developments along waterways requires project team members and decision makers to consider the realities of climate change alongside land use planning.

Siavash and Sheila offer three aspects to think about when implementing projects along our Indiana waterways. 

Consider the Ripple Effect

Waterfront and river corridor developments require taking the long view, both in terms of time and distance.

“Historical data shows that river levels have risen, and they’re projected to continue to do so,” Sheila says. “When planning for a waterfront development, make decisions not only for today, but for tomorrow, so that the investment stands the test of time.”  

In addition, it’s important to think about the entire watershed, not just where a project is located. “Consider how developments upstream will affect communities and neighborhoods downstream, both in terms of the types of development and strategies to deal with flooding,” Siavash says. For example, if you build within the floodplain of rivers, you’re taking up the flood storage space, which can cause problems elsewhere. "Hard armoring" strategies like levees and floodwalls can create issues upstream and downstream or become ineffective as water levels rise.

Use Nature-based Strategies

“Nature will find a way,” says Siavash. Give the river the room it needs, both today and in the future, by carefully considering the location of structures and spaces and avoiding development that severs the connection to the floodplain.

Instead of heavy development right next to the river, consider the use of trails and green space. While they may flood, these features give the river a place to go and provide temporary storage for its floodwaters. When building structures for public access, consider cantilevered elements, which provide less encroachment and less disturbance of flow patterns.

Rather than “hard armoring” within river corridors, think open space and “green infrastructure.”

“Strategies that mimic or harness the power of nature can absorb the river’s flow more effectively,” Sheila says.

Take Standards to a Higher Level

Higher water levels call for the consideration of higher standards. Siavash and Sheila encourage cities and towns to consider the effects of climate change when updating their technical standards, ordinances, and development codes. When implementing Capital Improvement Projects, to protect investment, weigh the positives and negatives of each decision based on the realities of public safety, economic development, and climate change.

“While there’s often disagreement about the cause of climate change, the data tells us it is happening, and we need to be aware of its potential influence on our communities and to prepare for it,” Siavash says.  “Our communities face many challenges and we need to find ways to adapt to the changes going on around us, including climate change.”

Christopher B. Burke Engineering can help you decode the data to make informed decisions about your developments and infrastructure serving your community. We look forward to helping communities create a sense of place alongside a sense of security for the future.

Sources:

https://ag.purdue.edu/indianaclimate/indiana-climate-report/

NOAA Climate at a Glance, NE Indiana Divisional Time Series

Data from US Geological Survey (USGS) streamflow gaging stations