County makes inroads with advanced modeling software

The Cherokee County Water and Sewerage Authority (CCWSA) in the southern US state of Georgia is due to begin advanced modeling work using Wallingford Software's InfoWorks WS solution after eight successful years using its companion solution, InfoWorks CS. The Authority is based in the City of Canton, population 200,000, and provides water to most of the county outside the city limits -- a customer base of 65,000-plus. There are several river basins in the county...

Dec 4th, 2007

CHEROKEE COUNTY, GA -- The Cherokee County Water and Sewerage Authority (CCWSA) in the southern US state of Georgia is due to begin advanced modeling work using Wallingford Software's InfoWorks WS solution after eight successful years using its companion solution, InfoWorks CS.

The Authority is based in the City of Canton, population 200,000, and provides water to most of the county outside the city limits -- a customer base of 65,000-plus. There are several river basins in the county, with the main one centered on the Etowah River.

The CCWSA cannot raise taxes, is not a part of Cherokee County government, and does not receive any tax revenue. The Authority is a public not-for-profit government entity tasked with providing drinking water and sanitary sewer services to Cherokee County.

Corey Ghorley, Water Model Specialist at Cherokee County explains that the Authority began using Wallingford solutions in 1999 when its then engineering consultant PBS&J was commissioned to choose water and wastewater network modeling solutions, which the Authority would then purchase.

Ghorley explains that the consultancy undertook research into various possible solutions and "came to the conclusion that InfoWorks was best suited to what we wanted it to do".

Work began with the consultancy incorporating the GPS point data that the Authority provided into the model; then one of the key figures at the consultancy, Jeff Hooper, joined the Association and the modeling work transferred in-house.

The early work focused on InfoWorks CS, as it was assessed as more critical, and on creating a sophisticated model of the County's wastewater infrastructure. This was undertaken within the Authority's GPS and GIS department, where crews are commissioned to obtain GPS data on the features of the network -- highly-accurate positions of key elements such as the 350 miles of sanitary sewers, inverts and manholes, are recorded and input into the model.

Because the County is in the foothills of the Appalachian Mountains, the elevation of the infrastructure varies from 900ft to 1300ft at the northern end of the area. On the wastewater side the Authority is fortunate that most of the flows reach the treatment works by gravity. However, the model has to include data on the various pump, booster and lift stations in the system. These are all connected to the Authority's SCADA system, which provides real-time data on the infrastructure that can be incorporated into the model to undertake real-time simulations.

The Authority is currently using the model to assess any infrastructure problems that may arise. The model is also valuable for simulating the addition of proposed new developments, allowing the Association to check whether there would be any adverse effect on the system. 'It has been a godsend to us,' Ghorley says. 'It's been very helpful.'

On the InfoWorks WS side, some work has been undertaken though not at an in-depth level, but the Authority is now gearing up to make fuller use of the solution's capabilities.

To this end, field crews have been following a similar process to that already undertaken for the InfoWorks CS model, tracking pipelines and hydrants and creating real-time GPS location data to survey-grade accuracy. Work on the basic data collection and validation process is now nearing completion and the Authority is on the verge of running a simulation. To date, 570 miles of pipes have been GPS located, and data on booster stations and tank reservoirs has been input.

The initial aim is to gauge the demands on the infrastructure against the amount of water available. From this the intention is to move into infrastructure maintenance, using the model to assess which elements of the system might need to be replaced.

The current demand on the system is estimated at 22MGD, and the treatment works can abstract up to 36MGD from the Etowah River, so the initial assessment is that the capacity is ample to meet current needs. However, the area is listed as fast growing so the Authority has had to move to proactive modeling of potential future demand to ensure that the capacity continues to be sufficient.

Because of the move to active modeling, Wallingford Software recently held on-site training at the Authority. Ghorley notes: "This was very helpful. I believe training in-house works out better for us, as it was one-on-one. We are a relatively small department, with just a couple of people working on the model, so it was extremely useful."

On the InfoWorks CS side, the Authority had sufficient data to be used in the simulations, with the InfoWorks WS training utilizing both in-house and test data. "It worked well," comments Ghorley. "It was real easy to learn."

Wallingford Software develops leading water resource management software for the worldwide water industry. Based in the United Kingdom, Wallingford Software has offices in the United States, Hong Kong, Malaysia, China and Australia, and a network of approved distributors throughout Europe, Asia and South America to provide sales and support services to Wallingford Software customers worldwide.

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