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Sanitary Sewer Collection

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.

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Site Development

April 27, 2021

Site Development


site layout and grading key
to project's success

Sunnybrook Village, Sioux City, IA

Project Owner:
AP Sioux City, Dallas, TX

Key Experience:

  • Building Layout Coordination
  • Site Access
  • Site Utilities
  • Significant Site Grading

Key Features:

  • 42-acre retail development
  • Two primary retail buildings
  • Four outlots
  • Free-standing buildings

The area’s growing population had generated demand for additional shopping options in Sioux City, Iowa. DGR Engineering (DGR) worked with the developer and initial tenants to develop a 42-acre retail subdivision on the south end of Sunnybrook Drive.

Prior to 2000, the area consisted of farm ground and an open ditch. The Sunnybrook Plaza project included installation of a 3,000 ft. box culvert through the site and grading to fill in the ditch. Also included in the project were utilities, a lift station, site grading and paving of Sunnybrook Drive to support the two main anchors, Target and Lowe’s, along with six other lots for future tenants.

Later, DGR projects included additional grading and paving of Sergeant Road, the extension of Sunnybrook Drive to Christy Road, and preliminary grading for the future site of Sunnybrook Village.

DGR worked with the developer to put together a preliminary layout for the site. However, when Fleet Farm expressed interest in putting a 200,000+ square foot building on the site, a significant revision was needed to fit the larger building footprint and required parking on the site.

The use of AutoCAD Civil3D® allowed DGR to redesign the site plans by moving the building pad back toward the hill and steepening the slope behind the building. Coordination between multiple entities to create a mutually satisfying layout of buildings, parking area, utilities and street access was a main element of the planning process.

The current construction will provide 274,000 square feet of retail space for Fleet Farm and Hobby Lobby, a free-standing Fleet Farm car wash/gas station/convenience store and room for an additional 44,900 square feet of retail space. 1,208 parking stalls will be provided in the initial phase of construction. Future development on the site will include four outlots for future stores or restaurants, as well as space for one additional free-standing building.

A challenge this job presented was the existing flood plain designation along Sunnybrook Drive. Documenting DGR’s previous design work on grading and storm drainage work enabled DGR to work with FEMA to obtain a Letter of Map Revision (LOMR). This removed the flood plain designation, allowing work to move forward on the project.

Site utilities include installation of water main and sanitary sewer to serve each building, as well as storm sewer to collect site runoff. The runoff will be delivered to an existing 72” storm sewer along the front of the site. It will then be carried into the existing storm water detention area on the south side of Christy Road.


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.

Lift Station, Control Panel, Valve Vault

July 18, 2019

The SE Sanitary Sewer Extension project provided sanitary sewer service to a previously un-serviced area southeast of Dell Rapids, SD. A significant portion of the project area was undeveloped  with shallow quartzite bedrock which attributed to the lack of utility service provided to this area. Included with this project was a lift station, control panel and valve vault along with the installation of 3,000 feet of sanitary sewer and over 1,000 cubic yards of bedrock excavation. Also included in the project were water main and sanitary force main installation.

DGR Engineering assisted the City in securing funding for the project through preparation of a preliminary engineering report and facilities plan. Preliminary engineering services followed which included field survey and utilities data collection to develop the base plan and profile, as well as analysis for preliminary design and cost estimates for the project. DGR also completed the final design as well as construction plans and specifications for the project. Construction engineering services included bid letting services as well as construction staking, observation, and administration for the project.

Site Development

November 5, 2018

DGR performed the boundary and topographic surveying as well as the site design of school building addition as a subconsultant of Architecture, Inc.
The school facility addition design included storm sewer upgrades, pedestrian facilities to multiple building levels, enhanced and expanded parking, as well as significant embankment work to match the existing site constraints.

The addition cut off an existing overflow drainage path so an enhanced storm sewer system capable of draining runoff from a 500 year storm event was designed and constructed.

This project required working with a building design team and ownership group to overcome design challenges and communicate with all project stakeholders.  The facility was completed and opened in late fall of 2015 for the Central Lyon Community School District.