BOISE - As growth continues at a rapid rate in the Gem State, the American Society of Civil Engineers, or ASCE, have found that Idaho's infrastructure is lagging behind.

Overall, the state was issued a "C-" grade Thursday for roads, bridges, dams and other structures.

"A lot of it is the growth, you know Idaho is the fastest growing state in the country, and there is getting more demand for infrastructure then we currently have," says Seth Olsen with the ASCE.

Of the seven categories engineers graded the state on, bridges were ranked the worst and were given a "D" grade.

The ASCE says half of Idaho's existing bridges on the state highways system are 50 years or older. Fifty years is the typical life span of a bridge.

"There are a lot of efforts being done by ITD and ACHD and local highway districts to improve the bridges within their jurisdiction but they can’t keep up, there's not enough funding out there for them to either replace the amount of bridges that need to be replaced or rehabilitated," says Olsen.

The state's roads also ranked poorly given a grade of "C-."

"Our roads, we need to have a little bit of extra help there," says Weiser Mayor Diana Thomas.

Thomas says in small rural communities like hers it’s difficult to come up with funding for much needed projects.

"We have a project coming up in our community over the next year and a half and it’s going to be about a $2.5 million project, it’s taken us almost 11 years to get the funding and do this project because we have to save up the match money in order to do that," says Thomas.

Statewide, the ASCE identified 1,520 bridges needing repairs that will cost the state $2.2 billion and a $3.6 billion shortfall over the next 20 years in funding for roads if federal and state funding remains as is.

Currently, in the state legislature, there are no transportation bills that call for an increase in transportation funding or bonding authority.

"So we have to be proactive about trying to get ahead and keep up with the growth that is occurring, if we don't then we are going to have these grades get worse, if we don't take advantage of the opportunities that come up for us to improve our infrastructure and keep up with that growth, then we're going to have more of a hard time than we already are making it happen," says Olsen.