Floods on Latah Creek during each of the past two winters scoured the riverbank so badly that four city bridges are being jeopardized.
The federal government has ordered the city to fix the banks around the bridges before the end of summer.
The city this week began advertising for bids to dump 1,280 cubic yards of rock around the bridge piers. That’s enough rock to fill 120 medium-size dump trucks.
Last week the City Council approved the project.
The four bridges are all on the lower reaches of Latah Creek. They are the crossings for Riverside Avenue, 11th Avenue, Chestnut Street and Inland Empire Way.
The Federal Emergency Management Agency has ordered the repairs and is contributing 75 percent of the cost. The rest of the bill will be split between the state and the city’s street maintenance fund.
City engineers estimate the job will cost between $75,000 to $120,000.
Work is expected to begin in three to four weeks.
The contract calls for restoring the upper parts of the riverbank with sod and new grass seed. The project includes 330 square yards of sod and enough seed to cover about 1,300 square yards of bank.
The seed will be sprayed in a method known as hydroseeding.
Floods in February 1996 and last New Year’s Day scoured the banks next to the bridge piers. The flood in January was measured at 25,800 cubic feet per second, which is as much water as the Spokane River carries during high flows in the spring.
, DataTimes ILLUSTRATION: Photo
Subscribe to the Coronavirus newsletter
Get the day’s latest Coronavirus news delivered to your inbox by subscribing to our newsletter.