The Massachusetts Firm-Yield Estimator, version 2.0

Release Date:


The firm yield of a reservoir is defined as the maximum yield that can be delivered from a system without failure, even during a severe drought. The Firm Yield Estimator model (FYE) uses the daily water-balance equation to estimate reservoir storage from October 1, 1960 to September 30, 2004, which includes the most extreme drought of record. The firm yield of a reservoir is calculated by iteratively solving the water-balance equation for each day of the simulation period, increasing the reservoir yield at each repetition until the reservoir storage is fully depleted for at least 1 day. The firm yield is the maximum yield that can be used in the water-balance equation without causing the reservoir to fail during the simulation period. Users may also specify monthly water usage patterns, monthly controlled releases, summer water restriction scenarios, and desired reservoir reliability in order to assess the effects of different reservoir management strategies. The model database contains all the requisite streamflow, climate, aquifer, and reservoir bathymetric data needed to compute the firm yield for 71 reservoirs in Massachusetts. Users may add new reservoirs and all the associated data to the model database in order to compute the firm yield of reservoirs not currently included in the model.

Documentation and limitations of methods

Levin, S.B., Archfield, S.A., and Massey, A.J., 2011, Refinement and evaluation of the Massachusetts firm-yield estimator model, version 2.0: U.S. Geological Survey Scientific Investigations Report 2011-5125, 49 p. Plus CD-ROM.

Report On-Line


Software (latest version posted October 19, 2011)

System Requirements

The FYE model was designed to run on a Microsoft Windows compatible personal computer (PC) and has not been tested on other operating systems or computer types. Windows is a registered trademark of Microsoft Corporation in the United States and other countries.


The zipped folders below contain the files needed for installation of the FYE. Select and save the file for the appropriate Windows version. Once the file is unzipped, click on the setup icon and follow the instructions for installation. Following installation, the program may be run from the start / programs menu.

Version for use with Windows 7 operating system: Link to FYE (95 MB)

Version for use with all other Windows operating systems: Link to FYE (95 MB)

User Manual

The user manual can be downloaded by clicking here.

Levin, S.L., User manual for the Massachusetts Firm-Yield Estimator, version 2.0 (MA FYE), Last updated October 2011.

Software History

MA FYE version 2.0 - Released October 19, 2011 to correct issues with summary reports and multi-reservoir system simulations.

MA FYE version 2.0 - Released October 18, 2011 to correct several issues associated with adding new reservoirs to the database and multi-reservoir system simulations.

MA FYE version 2.0 - Released October 5, 2011 to correct installation error

MA FYE version 2.0 - Initial release September, 2011.

User Support and known issues

Software may be updated occasionally to resolve runtime issues. If you would like to receive notifications of software updates, please email Sara Levin.

A list of known issues and resolutions can be found here.


User Rights

This software and related material (data and documentation) are made available by the USGS to be used in the public interest and the advancement of science. You may, without any fee or cost, use, copy, modify, or distribute this software, and any derivative works thereof, and its supporting documentation, subject to the USGS Software User Rights Notice

Product Disclaimer

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.