Central Contra Costa Sanitary District

Central San Reduces Capacity Planning by 30% with InfoWorks ICM

The Background

An Evolution of Sewer Modeling

Central Contra Costa Sanitary District (Central San) has always been on the cutting edge of sewer modeling technology. From an early adoption of PCs for tabular hydraulic analysis, to using a custom solution for a semi-dynamic 1985 Master Plan model, and then a custom GIS-based model in 2010, innovation has always been top-of-mind for Central San’s sewer modeling team. Following that trend, the District naturally evolved from steady-state to dynamic modeling. To tackle that challenge, Central San, with the help of Woodard & Curran, turned to InfoWorks ICM.


Justin Waples, PE, has worked for Central San for 10 years and is the Hydraulic Modeling Lead, as well as the Recycled Water Program Manager. He was instrumental in moving the District’s modeling capabilities from steady-state to dynamic with InfoWorks ICM. As a result, Central San was able to reduce capacity improvement projects by 30% - saving the district upwards of $10 million dollars and easing the cost burden for ratepayers.

The Challenge

An Increasingly Complex System, a Lack of Program Stability

With continual growth, and as one of the larger systems in the San Francisco Bay area (with over 1,540 miles of underground pipeline ranging in size from 6 inches to 102 inches in diameter), Central San needed to evolve their sewer model to meet the demands of managing an increasingly complex system. In their steady-state model, peak infiltration and inflow (I/I) rates were only attributed to the age of sewers - which were assumed to deteriorate over time. They were unable to model sanitary sewer overflow (SSO) volumes, pump stations, surcharge and backwater, and could not estimate sewer flow for specific times of the day. The steady-state platform was simply incapable of handling the advanced computational aspects inherent to modeling Central San’s system.


Central San embarked on acquiring a leading software solution that satisfied its hydraulic computational needs. Prior to selecting InfoWorks ICM, Central San’s previous modeling software was not enabled for workgroup collaboration, did not support version control or data audits, and lacked the ability for inference and engineering validation.

Just doing that one project for our capital planning paid for itself ten-times over. It’s definitely a big win for ratepayers, definitely a good savings. – Justin Waples, PE

The Solution

An Adoption of Dynamic Modeling, Improved Calibration

Justin advocated that the District select a solution that was commercially available, highly compatible, and widely respected to help Central San join the ranks of neighboring utilities and reach industry standard. 


After evaluating their options, Central San chose InfoWorks ICM. With this new tool, the District could now model pump stations, force mains, complex junction structures, overflow volume estimation, as well as bypass pumping and plugging. And, being commercially available, technical support, bug fixes, and new features were made readily available to Central San. “It was a critical component to our overall Master Plan, to get accurate flows in the collections system to identify what our true needs were for capacity improvements.” Justin said. He added, “InfoWorks ICM is known to handle complex hydraulic scenarios and that capability was essential for Central San’s needs.”


With InfoWorks ICM, collaborative work between the team at Central San and their consultant was made significantly easier. “If we’ve got too much going on, I can request that our consultant do the analysis - it’s quite seamless. They’ll run the analysis and we’ll get the information just as expected,” Justin noted

The Result

Huge Savings on Capacity Improvement Projects, Positive Impact for Ratepayers

After converting their steady-state sewer model to one that was dynamic, Central Contra Costa Sanitary District reduced their need for capacity improvement projects by 30%. In terms of savings, Justin estimated “it was at least $10 million dollars - probably a lot more.” For the remaining capacity projects, either pipe size and/or length of capacity improvement was reduced. Not only did InfoWorks ICM save the District money they would have used on capacity projects, it eased the burden of cost placed on ratepayers.


In closing Justin noted, “Just doing that one project for our capital planning paid for itself ten-times over. It’s definitely a big win for ratepayers, definitely a good savings.” Central San plans to continue expanding their InfoWorks ICM model to include key areas of interest and complete their system with smaller diameter pipes.

You can reduce capacity improvement needs and reduce costs for ratepayers with InfoWorks ICM