Downtown Des Moines' busiest bridge closes Monday for replacement
Thousands of daily commuters will need to find new routes over the Des Moines River starting Monday.
That's when the Grand Avenue bridge — downtown's busiest bridge, handling 7,600 vehicles daily — closes for a year while construction crews replace the nearly century-old structure. The $10.5 million project will cut a major link between the core business district and East Village until the end of 2017, when it's scheduled to reopen.
Then like dominoes, two more aging downtown bridges will fall and rise anew, and another three will be closed for refurbishing. The six bridge projects, totaling more than $38 million, will likely disrupt downtown traffic into 2023.
“Unfortunately, they were all kind of built bam, bam, bam,” Des Moines City Engineer Pam Cooksey said.
That hectic construction schedule in the early part of the 20th century gave the city its iconic arched bridges over the river along Locust Street (1909), Walnut Street (1911), Grand Avenue (1918) and Court Avenue (1918). Three of those bridges — Grand, Locust and Walnut — will be demolished and replaced. Only the Court Avenue bridge will remain. It will receive a major overhaul, as will the Scott Avenue and Meredith Trail bridges farther to the south.
“They’re all pretty similar age-wise and condition,” Cooksey said.
The rapid-fire pace of the six projects that start Monday stems from wear and tear the bridges have incurred over nearly 100 years or more of use and adds to a string of major construction projects that have disrupted business and commuter life amid a surge of downtown and East Village development.
“Just add it to the list,” said Amanda Krause, manager at Zombie Burger + Drink Lab. “We’ve been dealing with construction for a couple years.”
The popular Grand Avenue restaurant is located a few blocks east of the river and is one of the retail businesses closest to the bridge.
One bridge, 15 million pounds of concrete
Replacing the 450-foot Grand Avenue bridge is a massive undertaking.
Demolition will take about two months and involve removing pilings driven 50 feet below the river floor and into bedrock.
After new pilings get pounded or drilled into the riverbed, more new material arrives — a lot of it.
The project calls for 1 mile worth of concrete support beams, each nearly 4 feet wide and manufactured offsite. Those beams form the skeleton.
The bridge surface and exterior require 15 million pounds of concrete, which will be poured onsite. That’s somewhere in the ballpark of 500 truckloads, according to on-the-spot estimates produced by Steven Naber, deputy city engineer, at the request of The Des Moines Register.
“Holy mackerel,” Naber said after crunching the figures. “That’s a lot.”
The bridge will remain closed until December 2017, but even after its opening, construction will extend through summer 2018.
The new bridge design will reduce the number of piers in the river from four to three. It will also nearly double the width of sidewalks on the deck, from about 8 feet to 14 feet.
The bridge will include three traffic lanes, two of them westbound and one eastbound, plus a westbound bicycle lane and curb parking on the south side.
Due to cost restrictions, the arches on today’s bridge will be replaced by painted metal panels that create an arch-like facade. Arches are a historically significant look downtown: Three arched bridges appear on the city's flag. But installing a bridge with authentic arch supports to match the iconic theme downtown would have cost more than $30 million, according to original design estimates.
The arch design drew much discussion among the public and an aesthetics committee appointed more than two years ago to help plan for the bridge project.
City officials said the new arch-like facade will be used on the Locust and Walnut streets bridges when they are replaced as well. Each of the new bridges is expected to last about 90 years.
The arches on the Court Avenue bridge will remain intact when it is rehabilitated. The project will extend its life for at least another 40 years.
The Court Avenue bridge is the only one of the bridges that maintains a listing on the national historic registry. The other arched bridges do not qualify due to modifications made during previous rehabilitation projects.
Businesses prepare for closure
The owners of Brainstorm Iowa, a marketing and graphic design company, placed a bird feeder on the sidewalk in front of their shop at 333 E. Grand Ave. in the East Village last week.
That was after a digital sign appeared three blocks down the road to warn of the extended Grand Avenue bridge closure.
“If it’s going to be quiet around here, we might as well enjoy the birds,” said Paul Bridson, who runs the business with his wife, Kelly Sargent.
The firm moved across the river from the Court Avenue area two years ago to occupy a suite beside the Pink Beaver Waxing Boutique and across the street from Zombie Burger.
“We thought storefront on Grand Avenue, look at all this foot traffic we’re going to get,” Bridson said.
Instead, orange cones and a chain-link fence butt against their storefront, marking the construction site for a 90-unit apartment building to the west.
The project has closed the sidewalk for months. Same goes for the lot to the east of their building, where a hotel is being built.
“We have a construction zone for our front door,” Bridson said.
East Village parking will get worse before it gets better
The city-owned Brenton Skating Plaza, located adjacent to the Grand Avenue bridge along the Principal Riverwalk and Robert D. Ray Drive, will remain open during the bridge replacement.
Management at the facility has taken steps to prepare for the project by creating maps, securing alternative parking locations and blasting out information on social media.
“In the short term, it’s just a matter of education and helping individuals identify the ways to get there,” said Tiffany Tauscheck, spokeswoman for the Downtown Community Alliance, which oversees operations at the outdoor skating rink.
“The people who want to get to Brenton are going to find a way to get to Brenton.”
Funding downtown bridges
The city of Des Moines will pay for most of the $10.5 million cost for the Grand Avenue bridge with capital improvement dollars, but roughly $2.1 million is covered by federal money distributed annually by the Des Moines Area Metropolitan Planning Organization.
The city selected the Grand Avenue bridge as the first bridge to be replaced to coincide with the extended closure of Des Moines City Hall, adjacent to the site.
City Hall closed this summer for major renovations that could last up to two years. At the same time, contractors began work on a parking ramp that will replace a city-owned surface parking lot to the east of City Hall.
The city recently landed $8 million in federal funding for four of the other downtown bridge projects. The money comes from the Transportation Investment Generating Economic Recovery (TIGER) program under the U.S. Department of Transportation.
Locust Street is the next bridge project on the list. It is slated for 2018.
The Court Avenue bridge rehab is lined up after that. Closure dates for that project are expected to overlap with the Locust Street bridge closure.
Schedule for downtown bridge projects
Grand Avenue bridge replacement ($10.5 million including construction, planning and design): The bridge closes Monday and is expected to reopen to traffic at the end of 2017. Construction will continue through summer 2018.
Locust Street bridge replacement ($8 million construction estimate): Beginning fall 2018.
Court Avenue bridge rehabilitation ($7 million construction estimate): Beginning 2019.
Scott Avenue bridge rehabilitation ($3.9 million construction estimate): Beginning 2019
Meredith Trail bridge rehabilitation ($760,000 construction estimate): Beginning 2019
Walnut Street bridge replacement ($8 million construction estimate): Beginning 2022.
— The city has created a webpage to share updates about the Grand Avenue bridge closure, including detour routes, and other major projects.