European Union Water Initiative Plus for the Eastern Partnership Result 1 Report on methodology for identification of water abstraction limits depending on ecological flow needs for the rivers of Azerbaijan Baku, 2019 Disclaimer: The EU-funded program European Union Water Initiative Plus for Eastern Partnership Countries (EUWI+ 4 EaP) is implemented by the UNECE, OECD, responsible for the implementation of Result 1 and an EU member state consortium of Austria, managed by the lead coordinator Umweltbundesamt, and of France, managed by the International Office for Water, responsible for the implementation of Result 2 and 3. This document, the “Report on methodology for identification of water abstraction limits depending on ecological flow needs for the rivers of Azerbaijan”, was produced by UNECE at the request of the Ministry of Ecology and Natural Resources of Azerbaijan and with the financial assistance of the European Union. The views expressed herein can in no way be taken to reflect the official opinion of the European Union or the Governments of the Eastern Partnership Countries. This document and any map included herein are without prejudice to the status of, or sovereignty over, any territory, to the delimitation of international frontiers and boundaries, and to the name of any territory, city or area. Executive summary Excessive abstraction of water is one of the key problems of water management in Azerbaijan, which leads among other problems to drying out of many small rivers as a consequence of massive water intake. Ensuring environmental flows in rivers can protect the proper functioning of aquatic ecosystems, thus, contributing to meeting environmental objectives. In this context, the Ministry of Ecology and Natural Resources of Azerbaijan has requested support under the European Union Water Initiative Plus for the Eastern Partnership (EUWI+) programme for the elaboration of a methodology for identification of water abstraction limits depending on environmental flow needs and this work item was included in the national workplan under Result 1. In the preparation of this guidance document for Azerbaijan, major references were studied, including different approaches as presented in the EU Water Framework Directive (WFD) Guidance Document No. 31 on ecological flows, national references and approaches implemented at the level of different agencies of the United Nations. The WFD guidance document lists three major approaches to environmental flows determination - hydrological, hydraulic-habitat and holistic. Taking into account the current limitations in Azerbaijan, especially in terms of hydrochemical and hydrobiological monitoring, the proposed methodology is based on hydrological assessment, i.e. on examining historic data to identify suitable thresholds for flow abstraction. The proposed methodology can be refined and supplemented later, and the proposed environmental flow values can be adjusted as the monitoring network further develops in Azerbaijan in line with the WFD criteria. Assessment of hydrological regime and dynamics is an important part of assigning ecological status under the WFD and water quantity has an important impact on water quality and functioning of ecosystems. Discussions in the framework of the preparation of this report were held with key national stakeholder entities (Ministry of Ecology and Natural Resources, Azersu OJSC, Amelioration and Water Management OJSC, State Water Resources Agency, etc), including during the 8th meeting of the Steering Committee of the National Policy Dialogue on Integrated Water Resources Management (Baku, 12 July 2019). The participants of that meeting expressed appreciation to EUWI+ for the work accomplished and provided their comments and suggestions. It was also noted that the methodology can provide an important mechanism for ensuring adequate water quantity for river ecosystems. The present report contains methodology for identification of water abstraction limits depending on ecological flow needs for the rivers of Azerbaijan, as submitted to the Ministry of Ecology and Natural Resources. Annex I provides information on the long-term monthly average water discharges for the rivers of Azerbaijan and Annex II contains recommendations for ecosystem flow norms and water abstraction limits. The following experts contributed to the preparation of the present report: Farid Garayev (independent expert), Rafig Verdiyev (EUWI+ country representative), Professor Farda Imanov (Azersu Research Institute “SuKanal”), Alisher Mamadzhanov (UNECE). Vladimir Korneev (Central Research Institute for Complex Use of Water Resources, Belarus) provided valuable comments and suggestions. Introduction Identification of ecological status of water bodies is considered as a very important factor in the water resources management, and currently, the countries of the European Union apply this management approach, as required by the EU Water Framework Directive. According to that approach, when determining ecological status of water bodies, relevant requirements are also set for physical-chemical and hydro morphological supporting elements in parallel to biological quality elements. For instance, if biological quality elements and physical-chemical water indicators have high status, in order for the ecological status of a water body to be high (or close to natural conditions) it is required that hydro morphological quality indicators should be high as well. Otherwise, water status will be decided to be good, not high. And in further stages, it is considered that if based on initial two elements (biological and physical-chemical), water quality is good, then there is no need for checking hydro morphological quality/7/. Based on this, one can conclude that hydro morphological quality elements being a part of environmental quality indicators should also meet relevant requirements same as biological and physical-chemical quality indicators used in classification system that is envisaged in the Water Framework Directive/8/. In hydrological classification system, based on long term fluctuations of water quantity in the riverbed, water bodies can be divided into various hydrological categories. For each hydrological class category biological indicators can be identified, and if in the future, a change of hydrological status occurs as a result of water abstraction, then based on a related change of the corresponding biological elements, related ecological classification can be conducted. Therefore, the developed system establishes relationship between water use by different sectors and provision of flow for ecosystems and helps to improve water management and strong protection of ecosystems. In this proposed methodical approach, a hydrological classification system is developed to support the classification of ecological status of water bodies according to the Water Framework Directive. It is based on the comparison of water discharges observed within the given period of the year (for example for each 10 calendar days-decade, months or seasons) with the relevant hydrological indicators of the developed hydrological classification system , which is set based on the change of the long term characteristics of the flow of the considered period of the year by use of natural (not affected by human activities) flow ranges. The main hydrological indicators (thresholds) to be established for each status classes are set within the range of change of flow of the considered period of the year, from low to high values. Indeed the low flow values(water discharges) in the river compared to flow values of the other days of the considered period of the year provide limited living environment for water organisms, and the maximal ones in turn, provide widest living environment for water organisms and ensure better conditions for the reproduction and increase of the number of population of living organisms in the river and also for the surrounding of the river ecosystems and the range between these two levels covers all possible water conditions of the river . Therefore, this methodical approach is based on the Hydrological classification of water bodies by relating the observed daily water discharges in the considered period to the corresponding hydrological status classes created as a result of dividing the possible ranges of the long-term change of the flow in a river in that period into 5 status categories. Hydrological Classification System As mentioned, the term “Environmental Flow” is intensively used in several studies and scientific works for expressing quantity of minimal water, which is important to keep in the river and various environmental flow quantities are proposed to keep river ecosystems better protected /2,3,5,6/. The definition of the environmental flow, used in the calculation of the Sustainable Development Goal indicator 6.4.2 on the water stress is as follows: “...the quantity and timing of freshwater flows and levels necessary to sustain aquatic ecosystems which, in turn, support human cultures, economies, sustainable livelihoods, and wellbeing”. As described in the WFD Guidance document 31, most common methods for environmental flow estimation are the following: hydrological, hydraulic modelling of habitat environment and comprehensive (holistic) methods/5/. Hydrological methods are frequently applied in many studies, and it is mentioned that the other methods are both complicated and also require more reference (initial) information on the river and its basin /2,3,5,6/. In some of