The Great Lakes Water Balance
Data Availability and Annotated Bibliography
By Brian P. Neff and Jason R. Killian

Introduction | Hydrological Information | Forecasts and Summary

Precipitation

Precipitation data are used in different ways in water balance calculations. Direct over-lake precipitation is counted as a major input to the water balance. Over land precipitation is used to estimate runoff in areas where stream gaging is incomplete. It is important to note that there are currently no datasets of direct over-lake measurements. Therefore, estimates of over-lake precipitation are generally based on near-shore precipitation measurements (Croley and others 2001). Figure 2 shows the approximate location of all current weather stations in the Great Lakes basin.

Canadian Data 

In Canada, precipitation data are collected by EC from weather stations and archived by the National Climate Data Archive (NCDA). EC currently maintains over 300 weather stations and over 800 historical weather station records exist. The data can be retrieved with the assistance of the Ontario Climate Center (OCC). The data are quality assured and OCC provides these data on a cost recovery basis.

United States Data 

Precipitation data in the United States are archived by the National Climate Data Center (NCDC), a subsidiary of the National Oceanic and Atmospheric Administration (NOAA). NCDC maintains over 500 datasets of atmospheric and precipitation data. These datasets have all been subjected to some degree of quality control and assurance. In the interest of producing data in a timely manner, some of the most recent data are considered to be "preliminary". Assistance with accessing these data is provided by the NCDC office in Asheville, NC.

Ground Water

Direct discharge of ground water to the Great Lakes is generally ignored in water balance calculations. There are no widespread current or historical accounts of ground water discharge in to the Great Lakes. Nevertheless, some estimates of direct discharge do exist. The reader is referred to Grannemann and Weaver (1999) for a summary of current research on this topic.

References

• Bibliographies of selected references

• Full reference list

• Sources of Hydrological data and information

This report is prepared by USGS in cooperation with the Great Lakes Commission.

The Great Lakes Commission is a  multi-agency, multi-disciplinary, multi-faceted team approach to addressing the science and policy of a Great Lakes water management regime will produce such application-oriented products as a water use web site, updated annual water use inventories, ecological evaluations of the system, and an integrated binational role for future Great Lakes-St. Lawrence endeavors.