A computer model is available to assist in determining the appropriate cistern size for a given situation. The model uses rainfall data and anticipated usage to establish cistern inputs and outputs and provides a cost summary and usage statistics in a report form. Details on how to operate this model can be found in the user's manual, which is included as a .pdf file.
New features available in version 2.0 include an improved interface, reduced calculation times, an interactive graph of cistern levels, and the ability to save and load model inputs.
Installation Notes: Extract all files to a local drive and execute the program from that location. This program requires the Microsoft .Net Framework 3.5, which can be downloaded here.
Disclaimer: It is important to exercise professional judgement when using model results in rainwater harvesting system design. As a result, neither North Carolina State University nor the authors accept any responsibility for losses associated with the use of this model.
Version 1.5 of the Rainwater Harvester model can still be downloaded here. (2.9 Mb)
Rainwater Harvester is an evolving model; therefore, if you have any suggestions or encounter any problems, please send an email to NCSUWaterHarvesting@gmail.com.
Water Harvesting Lite
This flash application will provide an overview of how a water harvesting system can benefit you.