Update on I-69 Extension in Indiana

[Strider]

I'm curious... based on so many bridge piers built on the photos, is it also the floodplains that I-69 will go across in addition to the Ohio River, or are they dry lands prior to the Ohio River?

[silverback1065]

I'm curious... based on so many bridge piers built on the photos, is it also the floodplains that I-69 will go across in addition to the Ohio River, or are they dry lands prior to the Ohio River?

floodplains

[Rick Powell]

I'm curious... based on so many bridge piers built on the photos, is it also the floodplains that I-69 will go across in addition to the Ohio River, or are they dry lands prior to the Ohio River?

floodplains

In general, there is no reason to build on piers approaching a river unless the land is either in a flood plain, a federally protected wetland, or both, where building on fill would have negative effects on flooding or environmental quality. Roads on structure are typically more expensive to build and maintain.

[abqtraveler]

I'm curious... based on so many bridge piers built on the photos, is it also the floodplains that I-69 will go across in addition to the Ohio River, or are they dry lands prior to the Ohio River?

floodplains

In general, there is no reason to build on piers approaching a river unless the land is either in a flood plain, a federally protected wetland, or both, where building on fill would have negative effects on flooding or environmental quality. Roads on structure are typically more expensive to build and maintain.

Those piers are for the viaducts that will carry I-69 over the Ohio River floodplain. That area in particular is very prone to flooding whenever there is prolonged rainfall or spring snowmelt, so it makes sense to elevate the highway so it's not shut down every spring when the river floods.

[RoadWarrior56]

As an ex-Evansville resident myself and for many subsequent years while my parents still lived there while they were alive, I can agree with the last post.  Waterworks Road, which travels through the Ohio River floodplain on west side of US 41, was and is flooded and closed to traffic numerous years during the late winter and early spring.

[Rick Powell]

Those piers are for the viaducts that will carry I-69 over the Ohio River floodplain. That area in particular is very prone to flooding whenever there is prolonged rainfall or spring snowmelt, so it makes sense to elevate the highway so it's not shut down every spring when the river floods.

It's not so much the potential flooding on the I-69 pavement that requires a bridge section in the floodplain; INDOT could have built the bridge approaches on a high fill far above the potential flood elevation, and probably cheaper than a land bridge. But by doing so, they would likely cause backwater that would endanger the surrounding properties during flood events. Meeting the floodplain permit requirements for design and construction of I-69 was likely the biggest influence on what is being built.