• Christchurch City Council, New Zealand - City-Wide  Overflow Consent and Effects-Based Optimization  
  • Johnson County Wastewater, Kansas - Mill Creek Master Plan Optimization Review
  • Kansas City, Missouri - Overflow Control Program Optimization
  • Queensland Urban Utilities, Australia - Regional Sewerage Strategy Review
  • Gold Coast Water, Australia - Commonwealth Games Detailed Planning

      Christchurch City Council - City-Wide Overflow Consent and Effects-Based Optimization

  • Following the success of the 2015 optimization demonstration project for the Heathcote wastewater catchment, CCC engaged WCS Engineering to undertake a city-wide optimization of their wastewater capital improvement plan.
  • Due to the size and complexity of the network, the city-wide optimization approach included three phases starting with a high-level optimisation of conveyance alternatives and progressively including additional detail.
  • Following the second phase of the optimization (at which point preliminary solutions were produced), CCC engaged WCS Engineering to complete the 15-year historical rainfall analysis to determine overflow volumes and frequencies for the existing system and future planning alternatives.  These results were then compared to the optimization solutions to calculate the return on investment for capital improvements associated with each overflow.
  • The results from the analysis completed by WCS Engineering were coupled with an effects-based assessment of overflow impacts on ecology and community values to provide a framework for prioritizing investments. 
  • The city-wide optimisation Phase 3 underway in 2017 will couple location-specific overflow frequency targets with detailed improvement alternatives, including conveyance, storage, I/I removal and high-rate treatment.


     Johnson County Wastewater (JCW) - Mill Creek Master Plan Optimization Review

  • WCS Engineering was engaged by JCW in 2016 to review the Mill Creek optimization completed by another consultant in 2014.  Due to the complexity of applying Optimatics' optimization technology effectively, the first optimization attempt had not achieved a satisfactory outcome.
  • The review identified a range of alternatives for which the hydraulic and economic analysis required improvement and the optimization was redone.
  • The optimization, completed in 2017, identified a pragmatic and low-cost solution that included a range of contingencies for adapting the plan over time, based on extensive sensitivity analyses performed.
  • Optimization of the Marine Creek and Big Fossil Capital Improvement Plan.
  • Alternatives evaluated include inter-basin transfers, conveyance and wet weather flow control facilities (offline linear transport/storage facilities).
  • The objective of the optimization was to evaluate feasible alternatives and identify several low-cost solutions to contain the 5-year, 6-hour design storm.
  • The primary optimization scenario identified cost savings on the order of $20 M (20%) when compared to the Baseline Solution.
  • Optimization scenarios were completed with and without linear T/S alternatives.
  • The least-cost solution included two linear T/S facilities that helped to attenuate and disperse peak flows, thereby eliminating downstream conveyance improvements.

Consultant Team : Optimatics (Prime) and WCS Engineering

  • Detailed analysis of green and grey infrastructure alternatives.
  • Continuous rainfall data used to achieve EPA consent decree target of 4 overflow events in typical year.
  • Alternatives evaluated included green infrastructure (35 CSO Basins) conveyance, linear transport/storage, storage tanks, Real Time Control (RTC), inter-basin diversions, and asset condition improvement.
  • LTCP cost reduced by $112 M (27%).
  • CSO volumes reduced by an additional 30% compared to Baseline LTCP.
  • Sensitivity analysis used to test assumptions relating to the effectiveness of green infrastructure alternatives.
  • Prioritization of the LTCP demonstrated 76% overflow reduction within the first 21% of capital expenditure.

Consultant Team : Optimatics (Prime), WCS Engineering, Cardno, EmNet, and Greeley-Hansen

South Bend, Indiana

WCS Engineering Project Success Stories

  • Optimization of Slacks Creek Trunk Sewer Network.
  • Performance assessment of the steady-state 1,300 L/EP/Day PWWF solution under calibrated model scenarios.
  • Optimized solutions were developed for 6-month, 1-year, 2-year and 5-year design storm scenarios.
  • Alternatives evaluated include conveyance, storage and I/I removal.

  • The Baseline (PWWF) Solution did not effectively reduce overflows (achieving only a 30% reduction in 6-month design storm overflows).
  • The Optimized 1-Year Solution was shown to be 40% lower in cost than the Baseline Solution, eliminates overflows 1-year design storms, and significantly reduces overflows in the 2-year and 5-year events.
  • The Optimized 1-Year Solution was $10M (30%) lower in cost than the Conveyance-Only 1-Year Solution (i.e. significant value achieved through effective placement of wet weather flow control facilities and investment into I/I remediation)
  • Comprehensive Collection System Master Plan (CSMP) optimization.
  • Integrated analysis of hydraulic and asset condition-based drivers.
  • Alternatives evaluated included conveyance, storage, flow diversions, interceptor alignments and satellite treatment.
  • Extensive sensitivity analyses used to test population growth scenarios, model calibration accuracy and water conservation trends.
  • Input and advice from the 18-member Sewer Infrastructure Advisory Group (SIAG) and City Council.
  • Transparent and defensible process leading to unanimous approval of the CSMP by SIAG. Over $40 M (25%) savings compared to Baseline Solution.

Bend, oregon

Numerous Other High Profile Projects

Consultant Team : Logan Water Alliance, Parsons Brinckerhoff and WCS Engineering

Logan water, Qld

fORT wORTH, tEXAS

Consultant Team : MSA (Prime), WCS Engineering, Optimatics, Clearwater Engineering Group, and CH2M HILL

Over the past 14 years, the WCS Engineering team has completed over 50 projects using Optimatics software.  On each and every project we are committed to achieving and surpassing our client's expectations. 


We have contributed to over 15 water conference papers and presentations in the United States, Australia and New Zealand.  In 2009 we were awarded Best Paper Award and in 2010 Joel Wilson received the Young Modeler of the Year Award at the Water New Zealand Conference.     


More recent project summaries are available upon request.