Rising waters, why it’s happening and the impact on roads and bridges

A decade of higher-than-average rainfall and the devastating effects on state infrastructure is the topic on this week’s Talking Michigan Transportation. The conversation begins with Andy Dixon, a National Weather Service hydrologist who detailed the facts at a High Water Summit convened by Gov. Gretchen Whitmer Feb. 10.

https://www.michigan.gov/som/0,4669,7-192-47796-519367--,00.html

Following the conversation with Dixon, Brad Wieferich, director of MDOT’s Bureau of Development, talks about the impact of sustained high water on roads and bridges. An extended period of higher-than-average rainfall, record-high levels of the Great Lakes, inland lakes and swollen rivers and streams has eroded shorelines and made some roads impassable.

Daily Great Lakes levels, as tracked by the U.S. Army Corps of Engineers, remain well above their long-term average and continue to break records. In July 2019, the monthly mean level broke the record high July level, and it is the lake’s highest recorded July monthly level mean since 1918, the beginning of its period of record.

http://lre-wm.usace.army.mil/ForecastData/GLBasinConditions/daily-GLWL-Graph.pdf

Key facts illustrated by Dixon in his presentation at the High Water Summit:

- Overall, the last 10 years have been much wetter than normal across the Great Lakes states.

- As a whole, the state of Michigan is in the middle of the wettest one-year, three-year, and five-year periods since records began more than 120 years ago.

- Storms occur with more frequency. The previous average would have been 12-20 events in Michigan with waves of 10 feet or higher in fall/winter. Just through Jan. 21, we had 16-plus.

https://www.michigan.gov/documents/mdot/Spring_Flooding_Risks_EGLE_683531_7.pdf

The phrase is over-used, but is this the new normal? Whether it is or not, U.S. climate policy is unlikely to change dramatically anytime soon, says Amy Harder, energy and climate change reporter at Axios. As Harder wrote earlier this month, “Congress is likely to remain gridlocked on the matter.”

https://www.axios.com/climate-policy-changes-unlikely-7ecf6cc3-c42c-4d7c-b492-41d73433a015.html

MDOT’s Brad Wieferich talks about the impact the high water is already having on state roads and bridges and what the long-term impact could be. As he told the Detroit Free Press: Absent some interjection of federal disaster relief funds (which could only come if Michigan and then the federal government declared portions of the state as disaster zones, something that has not occurred), the regular state road budget, used to fix roads and bridges crumbling from age and wear, would have to bear those huge additional costs.

https://www.freep.com/story/news/local/michigan/2020/02/10/road-fixes-record-high-water-levels-could-top-100-million/4718140002/

Also discussed: the impact of rushing water on bridges and monitoring techniques for what is termed “scour.”

https://www.michigan.gov/mdot/0,4616,7-151-9622_11045_24249-487016--,00.html