- By Aung Zaw Min
Due to lack of knowledge based on ground- less facts about reservoirs and their benefits, this article is being written with the aim of understanding the nature of reservoirs and understanding the reality. The construction of reservoirs has been going on for ages around the world. Actually, a reservoir is an enlarged natural or artificial lake storage space for fresh water created, using a dam or lock to store water. Reservoirs can also be constructed in river valleys using a dam with retaining walls and levees.
Depletion of fresh water
Water is our most important resource and essential commodity for our existence on earth. Water is vital and a precious source for all of us, because there are many other ways water are used in our daily life, such as food, clothing and shelter. Due to the effects of increasing world’s population and high living standard, water consumption has increased year by year, on account of agricultural production and household use. On the other side, the world is running out of fresh water by dint of ‘reckless’ human activity and water deterioration as a consequence of global warming. Water covers 70 per cent of the Earth’s surface and it can reasonably be considered to be of a large volume, but in reality 96.5% of all the Earth’s water is contained within the oceans as salt water, while the remaining 3.5% is fresh water lakes and frozen water locked up in glaciers and the polar ice caps. Of the fresh water, only 2% of water can be utilized for the humans.
The effect of climate change
Although fresh water is plentiful in Myanmar, it has to encounter the hazards of flood, drought and other related natural disasters. The country has to face drought and flooding due to the climate change. The outbreak of disaster is likely to occur in many parts of the world and because of the impacts of climate change, many of these consequences occur, such as late arrival of monsoon, scarcity of rain, ground-water depletion and so on, across the country. The increasing scarcity of water has become a well-recognized problem, and efforts should be made to construct reservoirs aiming to cope with growing water scarcity and misuse and management of available water resources in Myanmar. Dams are very useful and important because they provide water for domestic, industry and irrigation purposes. Moreover, dams often improve the river navigation.
Preventing natural disasters
Many reservoirs have been constructed, under the supervision of efficient and experienced engineers from the Irrigation and Water Utilization Management Department (IWUMD) to prevent flash flooding and other natural disasters.
In 2015, torrential rains fell across the area of Min Myin Dam situated in Kanbalu, Sagaing Region. Due to the impact of climate change, the heavy and intense rain within a short duration in the Min Myin Dam Project area resulted in over flowing of the dam crest within a short period. Unexpected amount of reservoir water overflowed out from the spillway causing some extent of flooding in the downstream of the dam.
By incorporating the 2015 July flood data, new probable design floods, including standard project floods as well as probable maximum floods have been produced. The dam had been constructed to hold the rising water and prevent from overflowing, aiming to ensure the safety of the dam and its design life.
A reservoir is an artificial lake where water is stored and most reservoirs are formed by constructing dams across rivers. It can also be formed from a natural lake whose outlet has been dammed to control the water level. The dam controls the amount of water that flows out of the reservoir.
A spillway is a structure used to provide the controlled release of flows from a dam into a downstream area, typically the riverbed of the dammed river itself. Spillways ensure that the water does not overflow and damage or destroy the dam. Floodgates and fuse plugs may be designed into spillways to regulate water flow and reservoir level. Such a spillway can be used to regulate downstream flows – by releasing water in small amounts before the reservoir is full. Operators can prevent sudden large releases that would happen if the dam was filled over the brim. Other uses of the term “spillway” include bypasses of dams or outlets of channels used during high water, and outlet channels carved through natural dams. Water normally flows over a spillway only during flood periods – when the reservoir cannot hold the excess of water entering it over the amount used.
As for the IWUMD, all-out efforts are being made to conduct flood safety measures, with the cooperation of the locals. For the safety of the region, the IWUMD has already assigned high-ranking engineers in-charge to supervise and watch the conditions of embankments and the amount of moving water in the dams throughout the day and night. In doing so, the IWUMD goes through checking the stability and strength of the embankment, while taking preliminary measures to store up necessary equipment, such as machinery, tools and labour force.
For the safety of the people, the IWUMD has made an announcement that the occurrences of flooding are mainly due to incessant and torrential rains, and has advised the public that they should not believe every bit of baloney that are being rumoured about. The IWUMD has tried to disseminate accurate news and updates about the current conditions.
There is no standardization to measure which dams have reached the danger level. Only the dam embankments have this kind of standardization. Regarding safety measures, the IWUMD has assigned high-ranking engineers to supervise the conditions round the clock, and officials concerned are also fulfilling the requirements. Through the state-run media and Facebook, the IWUMD is issuing relevant information, news and updates to the public.
Win Ko Ko Aung