Experts state that sudden and heavy rainfall contributes little to both dams and groundwater replenishment, and this is the main reason for water scarcity in many regions today. Noting that long periods of drought and heavy rainfall have been observed in 20 years, Dr. Lecturer Ahmet Adiller emphasized that the most fundamental cause of water scarcity today is climate change.
Dr. Lecturer Ahmet Adiller: “When evaluated by per capita water availability, our country is experiencing 'water stress,' and according to studies, in the next 20-30 years, taking population growth into account, we are expected to become a country experiencing 'water scarcity.'”
Dr. Lecturer Ahmet Adiller, Head of Environmental Health Program at Üsküdar Üniversitesi SHMYO, evaluated the occupancy rates of dams in Istanbul.
Stating that “Istanbul, being the most populous city in our country, naturally has a very high water demand,” Adiller noted that according to official data, a very high amount of water is naturally used in the city where the population reaches 16 million.
Average daily water consumption in Istanbul is over 3 million cubic meters
Adiller stated that according to the 2020 data from the Turkish Statistical Institute, the daily per capita water consumption in Istanbul is 190 liters. “Even when we calculate with average values, we see that the daily water consumption is over 3 million cubic meters. In July 2023, a statement made by İSKİ shared information that a record was broken in water consumption, with approximately 3.6 million cubic meters of water used in a single day. Providing this amount of water is quite difficult, especially in the Marmara Region, which is not rich in water resources,” he said.
The drought we experienced this year may recur in the coming years
Dr. Lecturer Ahmet Adiller explained that when looking at the dam occupancy rates over the last 10 years, especially in November 2023, the dam occupancy rates have not dropped this low in the past, and continued:
“As of November 15, our dam occupancy rate is around 17 percent. Looking at previous years, we see that it was at 28 percent on the same dates in 2020. This gives us an idea that although the drought we experienced this year seems extraordinary, it may recur in the coming years.”
Studies should be conducted on water reuse
Stating that the daily per capita water consumption in Ankara, which has a high population density, is 246 liters, and in Izmir it is 221 liters, Dr. Lecturer Ahmet Adiller said, “From this perspective, it would not be correct to say that our citizens in Istanbul use a very high level of water. However, it is still important for us to save water and reduce water consumption to lower levels from many perspectives. To fundamentally solve this issue, especially considering that the population continues to increase, water saving alone will not be enough. In addition to water saving, studies should be conducted on the efficient use of water potential and water reuse, and effective population policies for Istanbul should also be worked on.”
Why do water levels in some dams drop from time to time despite rainfall?
Adiller first stated that not all precipitation directly fills the dams. “Dams only directly receive the rainfall that falls on their own surfaces. A portion of the precipitation that falls on land also feeds the dams with a certain delay. The amount of water that feeds the dams also varies depending on how the precipitation falls. For dams to be highly fed by rainwater, the precipitation needs to fall either as snow or as low-intensity rains at frequent intervals,” he said.
There is no significant decrease in precipitation amounts from past to present
Ahmet Adiller stated that sudden and heavy rainfall contributes little to both dams and groundwater replenishment, adding the following:
“Unfortunately, this is the main reason why we experience water scarcity in many regions today. When we examine precipitation amounts from past to present, we see that there is no significant decrease. In fact, there are even regions where it has increased. However, at this point, significant changes are observed in the way precipitation falls.
There is an average temperature increase of 1.2°C in Turkey
Unfortunately, the geography where our country is located is greatly affected by climate change. While studies show an average temperature increase of 0.72°C globally for the 1951-2012 period, they determine an average temperature increase of 1.2°C in Turkey over the 32 years between 1979-2010.
In the last 20 years, we have seen the effects of this with long periods of drought and heavy rainfall. This situation causes us to suffer material and moral damage in various ways. The most fundamental reason for experiencing water scarcity today is that we are deeply feeling the effects of climate change.”
What are the impacts of falling water levels on agriculture, energy production, and water supply?
Adiller also stated that water is needed in all human activities. “In some of these activities, we directly use water. Even if we don't directly use it in others, water is used for us in many different areas, from the foodstuffs we need to clothes, from goods to energy production. That's why water is one of our essentials,” he said.
Adiller also reminded that surface water sources like dams and ponds, along with groundwater, are direct raw materials for many sectors, and continued:
“According to the 2022 data from the Ministry of Agriculture and Forestry, 44 billion cubic meters (77 percent) of our country's 57 billion cubic meters of water usage is for irrigation purposes. This amount of water used for irrigation was 40 billion cubic meters 5 years ago, and 32 billion cubic meters 10 years ago. This increase over the years is not limited to agricultural water use only. In the last 10 years, both the demand for drinking and utility water and industrial water use have increased, and predictions indicate that it will continue to rise in the coming years. The effects of climate change are also expected to intensify in the coming years, where the need for irrigation is projected to increase.”
Approximately 20 percent of energy production comes from hydropower
Adiller also stated that according to the 2022 data from the Ministry of Energy and Natural Resources, approximately 20 percent of our country's energy production comes from hydroelectric energy production, and concluded his words as follows:
“This situation reveals that damages to water resources can also affect energy production. However, the fact that our country has a very high hydroelectric energy potential indicates that this situation can be prevented with planned investments.
We are a country experiencing 'water stress'
However, when we make a general assessment; our country, when evaluated by per capita water availability, is a country experiencing 'water stress,' and according to studies, considering population growth, we are expected to become a country experiencing 'water scarcity' in the next 20-30 years. In fact, even today, when regional assessments are made, we can say that our Marmara, Sakarya, and Küçük Menderes basins are facing this situation. If we do not use and manage our water resources correctly in the current situation, we can say that much more difficult days await us in the coming years.”