Who: Mesquite (Texas) Department of Public Works
Service area: 47 square miles
No. residents: 140,000 Miles of road: 1,123
Traffic signals: 108
Tons of refuse collected/week: 1,416
Drinking water provided: 16.7 mgd
No. employees: 251
Divisions: Engineering, Streets, Traffic Engineering, Solid Waste, Equipment Services, and Utilities
The 62 service requests on Mesquite, Texas' public works homepage read like a who's who of potential complaints. From “repair pothole” and “traffic signal lamp out” to “schedule a large item pickup” and “50/50 sidewalk replacement program,” all the usual suspects are there.
Here's what's not listed: Give us a new look, one that distinguishes us from all the other tired, old suburbs around here. Make our facelift so good it shames local businesses into spending millions to spruce up their look. Do whatever it takes to make our needs top priority with the state.
But that's what they're getting with two of the first projects launched to facilitate “Project Renewal.” Adopted in 2007, the city's long-term plan wisely makes infrastructure key to enticing developers into Mesquite instead of other potential Dallas-Fort Worth Metroplex locations.
Public Works Director Tim Tumulty, PE, and City Engineer Matt Holzapfel, PE, decided to widen a primary access point — Tripp Road and bridge — adding architectural flourishes to make the assets beautiful as well as utilitarian. They'd been pursuing their second project — an interstate exchange that's spawned $25 million in retail renovations and $92 million in proposed new development — for 15 years.
In the process, they set precedents for themselves, neighboring colleagues, and the state.
A SOLE-SOURCE SITUATION
Built in 1939 by the Works Progress Administration, Tripp Road's bridge was two lanes of asphalt with 2- to 5-foot-deep borrow ditches alongside. The goal was to turn it into a distinctive four-lane undivided concrete curb-and-gutter structure with internal storm drainage.
The 1-mile stretch of road and bridge presented multiple design challenges. A six-lane thoroughfare intersects the road within 200 feet of the bridge, which meant engineers couldn't change the grade of either. Extremely limited right of way around the primarily residential location necessitated negotiating and buying various types of easements and parcels.
The flood-prone region has extremely strict hydraulic requirements. A city ordinance prohibits designs from raising the 100-year surface elevation of a fully developed watershed upstream. So when his design showed the bridge would add 3/8 inch, Holzapfel had to get a variance to his own department's drainage requirement.
In 2003, Holzapfel went looking for a precast concrete bridge that could meet these specifications. Only one company offered shallow enough arches to provide sufficient hydraulic capacity within a limited height.
“The 430-linear-foot bridge was not a ‘basic model,'” he says. “We looked at many different systems but ended up specifying Conspan due to the shape of its arched section. At the time, other fabricators of precast arch products didn't have a product that met this unusual hydraulic requirement.”
Engineering consultants Kimley-Horn and Associates Inc. submitted floodplain modeling to the Federal Emergency Management Agency to obtain a Conditional Letter of Map Amendment before construction could begin. By the time the city went to bid, the economic boom had reached its apex. Material and labor costs were at their peak.
The city uses BidSync, an electronic bidding and procurement service powered by RFP Depot, to advertise requests for proposals. Of the 79 contractors who downloaded the notice, 46 asked for bid documents and six responded. When they were opened in January 2007, bids ranged from Rebcon Inc.'s $9.4 million to Texas Sterling Construction LP's $11 million.
The lowest were $48,000 apart but still more than estimated. Though the Mesquite Quality of Life Corp. had committed most of the funding — $8.7 million — public works tapped into unreserved water and sewer funds and contingency funds from another road project to make up the difference.
Construction took 158 days and was finished by December 2008. As demonstrated by the resident letter at left, it's evidently a success.