Publication // Management of sediment-induced problems at Tuyamuyun Hydro-Complex
By Sanjay Giri and Eric Stern. In this publication, a comprehensive review of the studies and data available as well as a rapid analysis of the sediment-induced problems at the Tuyamuyun Hydro Complex (THC) has been carried out. Additionally, the publication provides examples of global practices that could be useful while selecting and designing the measures for the THC.
Figure 2-4 The reservoir complex (left) and the headworks (right).
Within the scope of this assignment, we first have carried out a comprehensive review of the previous studies and data available as well as a rapid analysis of the sediment-induced problems at the Tuyamuyun Hydro Complex (THC). The review of the current state of the THC watershed system has revealed that the sediment-induced problems at the Channel (Ruslovoe) reservoir of the THC are rather severe and need to start being addressed. This has been in the making for the last 40 years. The sedimentation of the reservoir has resulted in not only storage loss but also has increased the risk for the safety of the populace and the in-water dam structures. A large layer of sediment deposition near the hydropower and irrigation intakes and spillways has resulted in the malfunctioning of the hydropower and irrigation structures and facilities as well as in increasing risks of flood and sediment hazards. There is also a significant storage loss leading to a water stress induced situation affecting the livelihood of more than 5 million people being benefited from the THC in the region (in Uzbekistan and Turkmenistan). Hence, by inaction, this resource can ultimately be lost.
We have categorized the problems as per their impacts and the urgency to address them. Accordingly, the measures have been characterized in two categories based on their types and scale. The 1st-category problem is related to the large deposition near the headworks (intakes and spillways) adversely affecting the functionality and safety of the structures (e.g., hydropower and canal operation) as well as the safe flood passage. The 2nd-category challenge is related to the storage loss of the Channel reservoir itself (almost 1.5 billion m3) due to significant sedimentation. Addressing this problem requires large-scale storage recovery efforts or alternative structural solutions.
In this report, we have also provided several examples of global practices and references that could be useful while selecting and designing the measures for the THC. However, there is no one generic method and technique. Thus, the proposed solution(s) and measure(s) should be designed specifically as per the local/ regional situations at the THC based on a comprehensive investigation on social, technical, environmental, engineering, and economic feasibility and impacts. Nevertheless, we have briefly outlined the impacts and prefeasibility of all the proposed measures in a generic way that can be applied and specific to the THC complex with follow- up assessments. We have also attempted to complement the proposed measures with the Nexus approach and reservoir sustainability that eventually contributing to the Sustainable Development Goals (SDGs).
Management of sediment-induced problems at Tuyamuyun Hydro-Complex
This publication is also available in Russian.
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- Nexus Regional Dialogue Central Asia // European Union supports water reservoir sedimentation treatment efforts in Central Asia