Water Balance Assessment in Iran: From Unsolved Problems to Practical Solutions

The development of water quantity assessment focusing on water balances have been identified as a main tool for guiding water policy and management at different decision-making levels. Water Balance Assessment (WBA) accounts for all water fluxes in a watershed by balancing the difference between water inputs and outputs, as well as changes in the watershed water storage. The natural hydrological cycle has been considerably changed due to the substantial anthropogenic activities, which lead to more complexity and therefore uncertainty in estimation and implementation of WBA results. In Iran, the WBA is being conducted every five-year for 609 watersheds, covering the whole country. Although the water authorities are provided with different guidelines and frameworks to improve the WBA, yet there are many multifaceted obstacles in carrying out proper WBA and implementing its results in water management. A preliminary survey showed that most of the barriers are related to the complexity of the human-hydrological watershed systems and the associated uncertainty to the water balance components especially at semi-arid watersheds. Additionally, the complexities associated with institutional arrangements including: access to data, centralized process of conducting WBA, workflow of the WBA projects, diverse stakeholders and their disagreement with WBA final results are among the barriers against smooth WBA in Iran.

In order to understand, identify and provide practical solutions for WBA problems, a national initiative is established with engaging government organizations, universities, NGOs, and research institutes. Therefore, we introduced a collaborative framework entitled “Unsolved Problems in Water Balance (UPWB)” to understand the problems together, co-create capacities and synergize among all stakeholders to solve the WBA problems in Iran. UPWB also covers 11 out of 23 of the IAHS Unsolved Problems in Hydrology (UPH). The UPWB considers three main themes for prioritizing the UPWB in Iran: 1) Technical and computational 2) Institutional and 3) data and information. So far, 10 online webinars by involvement of 400 experts are organized and 46 filled questioners also collected through the Web platform (upwb.ir). Preliminary results confirmed that WBA is the core element of sustainable water management especially in semi-arid regions with various technical, social and institutional aspects.