The Massachusetts Reservoir Simulation Tool

Release Date:


The Massachusetts Reservoir Simulation Tool is a screening-level model developed to examine the effects of reservoirs on the natural streamflow of streams in Massachusetts. The Massachusetts Reservoir Simulation Tool simulates the daily water balance equation of a water supply reservoir and estimates the magnitude, frequency and duration of spillage below the dam over the period of record. The application has a menu-driven user interface that allows the simulation of single- or multiple-reservoir systems.

Documentation and limitations of methods

Levin, S.B.,2016, Effects of water-supply reservoirs on streamflow in Massachusetts: U.S. Geological Survey Scientific Investigations Report 2016-5123, 35 p., available online at:



System Requirements

The MA Reservoir Simulation Tool was developed in Microsoft Access and is compatible with Microsoft Access version 2010 and later. The tool has not been tested and is not supported for operating systems other than Microsoft Windows. Windows is a registered trademark of Microsoft Corporation in the United States and other countries.


Click on the link below to download a .zip file containing the Reservoir Simulation Tool Access database.

Software Download (95 MB)

User Manual

The user manual can be downloaded by clicking here.

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

Additional Information

Multi-reservoir system configurations

The Massachusetts Reservoir Simulation Tool includes data for 13 multi-reservoir systems in Massachusetts. System configurations for all systems were compiled in Waldron and Archfield, 2006 and Levin and others, 2011 and can be downloaded here

Source Code

Visual basic source code for the water balance simulation and computation of all simulation summary metrics included in the Massachusetts Reservoir Simulation Tool can be viewed below.

SingleRes.bas: Water balance simulation of a single-reservoir system

MultiRes.bas: Water balance simulation of a multi-reservoir system

OutputMetrics.bas: Code for computing spillage metrics displayed in simulation summary

PublicFunctions.bas: Additional functions that are used within the simulation routines


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., available at:

Waldron, M.C., and Archfield, S.A., 2006, Factors affecting firm yield and the estimation of firm yield for selected streamflow-dominated drinking-water-supply reservoirs in Massachusetts: U.S.Geological Survey Scientific Investigations Report 2006-5044, 39 p.


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.