Lesotho WEAP Manual

Water management and allocation models are often used to help water managers make informed decisions. To support the robust decision making (RDM) process in Lesotho, this project used the Water Evaluation and Planning (WEAP) model to examine hydrologic dynamics in the Orange-Senqu river basin. This section describes the WEAP model’s broad capabilities and the process for implementing the model in Lesotho. This project developed a WEAP model to represent the main water supply and demand features for the Kingdom of Lesotho. The model was developed at a spatial scale appropriate to simulate major hydrologic flows; to represent major demographic trends; and to evaluate the effects of water management responses. Monthly observations between 1950 and 2005 were used to calibrate WEAP (See Annex A) to enable it to consider future climate and water management scenarios from 2010 to 2050.