Challenge
The Amana Colonies, a group of seven historic villages located along the Iowa River in Iowa County, operate independent water systems through the Amana Society Service Company (ASSC). Following an inspection, the Iowa Department of Natural Resources (IDNR) noted deficiencies including low water pressure in two systems and positive bacteria tests. While ASSC had already taken steps to address water quality by adding chlorination at specific wells, they still needed support in evaluating the overall water system and developing a comprehensive model to guide improvements, meet current demands, and plan for long-term growth.
Solution
ASSC engaged HR Green to perform a system-wide assessment of water sources, storage, pumping, and distribution infrastructure. A critical component of this effort was a detailed distribution system evaluation, which included:
- Hydraulic Modeling: A WaterGEMS model was developed to represent five of the seven village systems. Average day and maximum day demands were input based on ASSC data, with projections extended 20 years to account for anticipated population growth and system expansion.
- Calibration: Anticipated pipe friction coefficients were applied, based on pipe age, diameter, and material provided by ASSC, to accurately simulate real-world conditions.
- System Deficiency Identification: The model revealed areas of low water pressure, ineffective turnover within existing towers, and zones with high water age caused by dead-end mains and limited interconnection between colonies.
- Operational Scenarios: Multiple tower configurations, well operation sequences, and flow transfer routes were tested to evaluate reliability, identify bottlenecks, and measure redundancy.
- Improvement Alternatives: Using the model results, HR Green developed a prioritized set of improvement options, including demolition of the five undersized and inefficient towers, construction of a single 250,000-gallon elevated storage tower in a central location, and targeted piping and well upgrades to improve hydraulic balance and resiliency.
- Implementation Guidance: The evaluation included planning-level cost estimates and phasing recommendations to help ASSC stage capital investments while maintaining service during construction.
Benefit
The modeling effort provided ASSC with a clear roadmap for improvements, addressing immediate operational issues while supporting long-term growth. By investing in a modernized and efficient distribution system, the Amana Colonies can deliver reliable service to residents and businesses while preserving the community’s historic character and planning for future demand.
