If you want to work on water stewardship, it is not easy to find information on catchment water balances. With the Catchment Water Balance app, basic water balance data be viewed and downloaded for any catchment around the world. Once downloaded, the information can be made more complete by adding local data on reservoir storage, water transfers in and out of the catchment and water use by irrigated agriculture. How to create catchment water balances is described in our technical paper on the water balance methodology.


To create the water balance app we used open access data from TerraClimate (1) and Hydrosheds (2) and a bit of programming on the Google Earth Engine. After clicking in the map,  the simple app presents a graph with the monthly water balances of the selected catchment. The water balance is based on global data and gives an indication of the natural monthly water balances in a catchment. Man-made storage or transfer of water into or out of the catchment or use by irrigated agriculture are not incorporated in the water balances. These data can be estimated based on local data sources and added by hand.

A big thanks to the data providers below!

(1) Abatzoglou, J.T., S.Z. Dobrowski, S.A. Parks, K.C. Hegewisch, 2018, Terraclimate, a high-resolution global dataset of monthly climate and climatic water balance from 1958-2015, Scientific Data 5:170191, doi:10.1038/sdata.2017.191

(2) Lehner, B., Grill G. (2013): Global river hydrography and network routing: baseline data and new approaches to study the world’s large river systems. Hydrological Processes, 27(15): 2171–2186. Data is available at www.hydrosheds.org