Methods used to estimate daily streamflow and water availability in the Massachusetts Sustainable-Yield Estimator version 2.0

Abstract

the Massachusetts Sustainable-Yield Estimator. To compute water-use-adjusted streamflow, mean daily withdrawals and discharges within a user-defined basin are subtracted and added to the unaltered time series, respectively. Surface-water volumes are applied directly to the equation. Time-lagged streamflow alterations from groundwater withdrawal or wastewater discharge sources are estimated by using a responsecoefficient method developed from results of previously published, calibrated groundwater models in Massachusetts. The Massachusetts Sustainable-Yield Estimator was updated to version 2.0 to improve software stability and usability. The version 2.0 software application was developed in Microsoft Access with a graphical user interface. All geoprocessing steps, including basin delineation and compilation of basin characteristics and water use within the basin, were completed in the Massachusetts StreamStats web application and exported for use by the Massachusetts Sustainable-Yield Estimator version 2.0.

User guide for the Massachusetts Sustainable-Yield Estimator (MA SYE—version 2.0) computer program

“…Version 2.0 (v2.0) of the MA SYE uses analytical methods that were developed and used for the original Massachusetts Sustainable-Yield Estimator (MA SYE version 1.0) (Archfield and others, 2010) and the Rhode Island hydrologic drought decision support system (HyDroDSS version 1.0) (Granato, 2014). The application of these methods for the MA SYE v2.0 is described in more detail by Levin and Granato (2018). The MA SYE calculates percentiles of daily mean flow by using regression on basin characteristics; distributes these percentiles of daily mean flow over a long-term time series by using an index-streamgage record; calculates available yields of daily mean streamflow by using user-defined flow targets; calculates water-use-adjusted values of daily mean streamflow by using water-use data; calculates estimates of the accuracy and uncertainty of estimated unaltered streamflow; and calculates selected streamflow statistics by using standard statistical methods.…”

“…The MA SYE calculates percentiles of daily mean flow by using regression on basin characteristics; distributes these percentiles of daily mean flow over a long-term time series by using an index-streamgage record; calculates available yields of daily mean streamflow by using user-defined flow targets; calculates water-use-adjusted values of daily mean streamflow by using water-use data; calculates estimates of the accuracy and uncertainty of estimated unaltered streamflow; and calculates selected streamflow statistics by using standard statistical methods. These methods are described in detail by Archfield and others (2010), Granato (2009Granato ( , 2014, Granato and others (2017), Granato and Levin (2018), Farmer and Levin (2018), and Levin and Granato (2018). These methods also are described within the explanations and context-sensitive help available within the MA SYE GUI.…”

“…By default, all these text-file outputs echo all the application inputs, unless the user decides to deselect the option to export the input values. Uncertainty multipliers (Farmer and Levin, 2018;Levin and Granato, 2018) also can be examined and exported in a text-file format. With the exception of the daily flows, all the text-file outputs can be copied as text from the output form or saved in text-file format from the output form.…”

“…Sustainable water-use estimator tools provide planninglevel estimates of streamflow at a selected site and the potential effects of water use on that streamflow (Archfield and others, 2010;Levin and Granato, 2018). This information is needed to help decision makers balance human water needs with the instream flows needed to sustain healthy ecosystems.…”

“…This report is a guide to describe the implementation and use of the MA SYE computer program (Granato and Levin, 2018), which is available on the USGS ScienceBase-Catalog website (https://doi.org/10.5066/P95VX5AX). The theory and application of methods of estimating streamflow and sustainable water use are described by Levin and Granato (2018). This user guide provides brief overviews of the numerical methods, graphical user interface (GUI) of the MA SYE, and logistics for implementation and use of the Microsoft Access database application.…”