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Utility Improvements

Street & Utility Improvements

July 28, 2021

Street & Utility Improvements

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Sioux City Project updates
Morningside Avenue

Project Owner:
City of Sioux City, IA

Key Experience:

  • Planning and coordination with local businesses to maintain access during construction
  • Improving drainage along the corridor by adding storm sewer
  • Major intersection reconstruction completed half at a time

Key Features:

  • New utilities (sanitary sewer and water main) including adding storm sewer where none previously existed along with decorative street lighting and colored concrete sidewalks
  • Several stages of construction allowing business access at all times during construction
  • Involved a major intersection of two arterial streets with Morningside Avenue and S. Lakeport Street

Morningside Avenue is a main arterial street though the Morningside neighborhood of Sioux City, IA. The original infrastructure dated back to the early 1900’s, with streetcar tracks actually buried under the paving. This project also included the intersection of S. Lakeport Street, a north-south arterial street that extends to Gordon Drive.

Morningside Avenue was reconstructed from just east of S. Nicollet Street to east of S. Lakeport Street totaling approximately 1,300 linear feet. The project included new sanitary sewer, water main (replacing two existing mains), storm sewer, fiber conduits, decorative street lighting, and 9-inch concrete paving with colored concrete sidewalks.

To provide customer and truck delivery access to adjacent businesses, the project was completed in seven stages (including removing/replacing temporary crossovers on S. Lakeport Street through a raised median).

Stage 1a was installing new storm sewer along a portion of S. Clinton from Morningside Avenue to south of intersection of Garretson Avenue and S. Clinton. This provided a storm sewer outlet for Morningside Avenue where none previously existed.

Stage 1b was the reconstruction of Morningside Avenue from just east of S. Nicollet Street east to S. Henry Street.

Stage 2 was extending the reconstruction of Morningside Avenue from S. Henry Street to just short of the S. Lakeport Street intersection.

The final four stages included reconstruction of the intersection of Morningside Avenue and S. Lakeport Street in order to replace utilities and install a new traffic signal. DGR Engineering (DGR) coordinated with the City and contractor to maintain one lane of northbound and southbound traffic on S. Lakeport Street at all times throughout the entire project.

Stage 1a and 1b were completed in 2018. Stages 2, 3a, 3b and 4a and 4b were completed in 2019.

DGR services included gathering survey and utility data needed to prepare detailed plans and specifications as well as construction administration and observation using Federal Aid Funding for the reconstruction of Morningside Avenue.

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Sanitary Sewer

July 20, 2021

Sanitary Sewer

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Gravity sewer provides for both existing and future development

Sioux City’s Southeast Morningside Sanitary Sewer

Project Owner:
City of Sioux City, IA

Key Experience:

  • Lift station improvements
  • Large diameter sewer design
  • Gravity siphon design
  • Directional bore sewer installation
  • Low water crossing

Key Features:

  • 10,069 linear feet of 24” and 30” gravity sewer
  • 4,628 feet of twin 10” force main
  • VFD pump controls
  • Flow meter installation

The City of Sioux City had been seeing residential development on the east side of the city in the area of Whispering Creek Golf Course. The hilly terrain, however, limited the area that could be served by the existing sanitary sewer lift station on Whispering Creek Drive. This lift station was also experiencing problems due to the limited capacity of the gravity sanitary sewer to which the force main from the lift station was discharging.

DGR Engineering (DGR) worked with the city to develop a plan for a new gravity sanitary sewer that would open up additional development area as well as provide adequate capacity for discharges from the Whispering Creek sanitary sewer lift station.

In the early 1990’s DGR designed the Southeast Morningside sanitary sewer lift station in the southeast corner of the city. The location of this new Southeast Morningside Lift Station allowed for gravity sewer service to area which is now home to the Sunnybrook Plaza, Sunnybook Village and Lakeport Commons commercial areas in the southeast corner of town and was also designed to provide addition future capacity though pump upgrades to serve additional residential development including the area where the city was seeing growth.

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The final plan included over 10,000 feet of 24” and 30” gravity sanitary sewer starting at the Southeast Morningside Lift Station and running south and east along an existing drainage way and then north in an abandoned railroad right of way to Old Highway 141. The gravity sewer continues north through portions of the new Eagle Ridge and Whispering View Subdivisions. An inverted siphon was required for the crossing of the existing creek just south of the Southeast Morningside Lift Station. A granular access road was constructed along much of the gravity sewer to provide maintenance access. A low water crossing was installed at the creek in one location as an alternative to much more expensive box culvert or bridge options.

The upper end of the gravity sewer serves as the discharge point for twin 10” force mains (one for current conditions with a second for future development) from the Whispering Creek Lift Station.

The force mains run along portions of the Whispering Creek Golf Course and cross under holes 1 and 9 requiring a 1,000 foot long directional bore.

The Whispering Creek Lift Station was retrofitted with VFP pump controls to reduce operating cost and better match the pump output to existing and future flows. A flow meter was also installed in a vault downstream from the lift station to meet current IDNR requirements.

The new gravity sewer is already being utilized by several new additions to the Whispering View Subdivision and the initial phase of the Eagle Ridge Subdivision.

Funding for the project included the use of state Revolving Loan funds to be repaid with future sanitary sewer service area fees.

Click here to read this story in the newsletter.

Site Development

April 30, 2021

Site Development

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new sioux city school built
on site of existing facility

Multi-year, Multi-stage Project Maximizes Usable Space

Project Owner:
Sioux City Community School District, Sioux City, IA

Bryant Elementary School

Key Experience:

  • Maximize usable space in a tight area with steep terrain (26.5 feet of elevation difference across the site)
  • High level of project coordination with entities involved, included school, city, neighbors, architects, engineers, private utility companies and contractors to layout and complete a schedule for a multi-year, multi-stage project with three bid packages within a proposed budget
  • Reconstruct surrounding streets during site work

The central core of Sioux City, IA is growing in student population and with an existing building constructed in the late 1800’s, the school district listed Bryant Elementary School as a top priority for replacement. It was determined using a school district demographic study that a school capable of housing 650 K-5 students would be required. In 2012, DGR Engineering assisted with site selection for the proposed school building. After thorough review of over a dozen possible sites, the existing Bryant Elementary School site was chosen. Due to the increased need in building size, the existing 2.48 acre site was expanded to 4.31 acres through acquisition of eight residential single-family dwellings as well as some City right-of-way (street and alley). A multi-year, multi-staged project that included three bid packages was planned.

Following approval of the plan to expand the existing site to the south and east, property acquisitions and relocations commenced. Bid Package 1 (BP1) included building and site demolition, utilities and grading which included over-excavation and re-compaction of soils below proposed building footings and foundation, retaining walls and paving.

Also during this time, Jennings Street, 31st Street and Jones Street, which were similar in age to the existing school, were reconstructed in a partnership agreement with the City of Sioux City. Along with street reconstruction the utilities were replaced. There were existing 30” water mains in Jones and Jennings Street (with different pressure ratings) that were improved by installing internal seals at the joints. These existing 30” water mains were potholed during design phase to establish location and elevation in order for other proposed utilities to cross them without conflict.

A total of approximately 1,675 linear feet of street including four intersections plus 200 linear feet of relocated City alley through the site was replaced. Work on BP1 was completed in fall of 2017.

Bid Package 2 (BP2) was also completed in year 2016 in coordination with BP1 and included two site geothermal well fields totaling 230 wells at approximately 300 feet deep. The geothermal well field will heat and cool the new school and has been the practice with all the new elementary schools in Sioux City since 2007.

Finally, Bid Package 3 (BP3) included the building construction with remaining site work (final grading, sidewalks, fencing, etc.) adjacent to the building.

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Street and Utility Improvements

April 16, 2021

The City of Irene made a big decision to invest tax dollars and utility fees into significant reconstruction work and to pursue funding to upgrade the remaining infrastructure, improve drainage, and install new street surfacing. DGR Engineering (DGR) went to work immediately, pursuing potential funding options. The City was successful in receiving a funding package. In all, 74% of the project cost was covered by grant funding!

Design of the project included new PVC water main, new PVC sanitary sewer and RCP storm sewer. Sanitary sewer in some areas was lined using a CIPP process, which avoided digging in yards. Manholes were either replaced or lined. The pavement section included geotextile fabric, aggregate base course and asphalt surfacing. Many trees in boulevard areas were removed to facilitate roadway and utility improvements. The project area included complete reconstruction of approximately 25 blocks, which was completed between March and November of 2020.

The existing lift station consisted of a wet well and a dry pit valve vault which was located in the highway right-of-way. The City purchased property to allow the lift station to be relocated out of the highway right-of-way and to be replaced with a new wet well and a package above-ground lift station to include valves and controls. Complete utility infrastructure replacement.

Force Main Replacement

April 15, 2021

The City of Brandon’s existing sanitary sewer force main had separated under Split Rock Creek along the north side of Aspen Boulevard. The City put a temporary force main in place to maintain service to the residents east of Split Rock Creek, which ran across the Aspen Boulevard bridge over the creek.

To avoid the line freezing, and prevent the potential issue of the exposed temporary force main being damaged by traffic, the City needed a repair project designed and constructed in a short time frame. DGR Engineering (DGR) was contracted to design a new force main that would be installed under Split Rock Creek, and at the same time, a new 16” water main was designed to replace the existing water line to facilitate future development needs.

The City had also been experiencing severe erosion in the ditch east of Split Rock Creek and wanted to address that issue along with the project. DGR engineers worked with several suppliers to find an appropriate erosion control solution that would withstand the runoff flows and grades in the ditch up to 15%. Flexamat was chosen as the best product to meet the needs of the City.