Salinity intrusion - threat to water safety

On July 31, 2017, ministers, senior government officials, businesses, representatives of non-governmental organisations (NGOs) and development partners gathered at the Fourth Consultation of the UN High Level Panel on Water (HLPW) on Valuing Water, at the BRAC Center Inn, Bangladesh. This high-ranking assembly highlighted the myriad water-related problems Bangladesh has long been facing, which include scarcity of pure drinking water, improper use of water, lack of managing and conserving water etc. Speakers also mentioned that fresh water is facing a crisis around the world, compounded by extreme weather conditions like droughts and floods. Water sources are threatened by overuse, pollution and climate change. Speakers also suggested that we have to change our lifestyle to cut water use, and stressed the need to innovate new varieties of crops, which could be cultivated with a small volume of water.

The goal of the Valuing Water Initiative of HLPW is to achieve water-related Sustainable Development Goals (SDGs) by inspiring better decision-making, and making better trade-offs between competing claims on water. In the agenda of 'Valuing Water' almost all water-related problems appeared except salinity intrusion in water in the southern region of Bangladesh, especially the coastal areas.

Due to invasive water salinity, people are being infected with different diseases in which suffering of the pregnant women and children are immense. Last year, a leading daily newspaper reported that pregnant women in the country's southern region largely affected with anaemia and high blood pressure during pregnancy are the leading cause of having high salt intake in potable water that causes increasing risk in the maternal and newborn health. This statement was based on the study report conducted upon 202 pregnant women who came to take health service to Dacope Upazila Health Complex, Khulna district. This study established a great shock for the vulnerable people of the coastal region in Bangladesh.

The study revealed that salinity in drinking water is associated with increased risk of (pre) eclampsia and gestational hypertension in this population. For this reason, children may be born early, not be mature, shaped as smaller than usual, and may even die. High brackish water intake is also closely associated with the risk of hypertension in adults. Besides, people of the southern part of Bangladesh, especially of the delta belt, have been suffering a lot from various diseases caused by arsenic contamination, water pollution etc. For salinity intrusion, vegetables of this region also become salinity-torn.

In the past, a large part of Bangladesh's population obtained most of their drinking water from surface water sources, such as ponds and rivers. As a result, there were widespread deaths from diarrhoeal diseases such as cholera due to the presence of microbiological pathogens in surface water sources. In the 1970s, there was a campaign led by UNICEF to promote tube wells throughout the country. During this time, there was a significant decline in deaths from diarrhoeal diseases in the country, both due to availability of safe water as well as the use of oral dehydration solution.

Since then, much effort has been taken at the policy level to combat this issue. The government established policies and strategies such as the National Policy for Safe Water Supply (1998), National Water Policy (1999), National Policy for Arsenic Mitigation (2004) and the Water Safety Framework (2011). Now, the country has made notable development to improve the water and sanitation situation. As per the report of WHO/UNICEF Joint Monitoring Programme, access to improved drinking water sources is at 87 per cent in Bangladesh.

Now, salinity intrusions into vast swathes of the south-western region have gained serious proportions.  A daily newspaper report said that the current magnitude of salinity intrusions can be gauged from the fact that 93 upazilas of 18 south-western districts are affected by it. As many as 20 million people in the coastal belt have no access to potable water causing various diseases on top of hindering farming and leading to loss of livelihoods. A 2016 study revealed that Bangladesh's coastal population, comprising approximately 40 million, relies heavily on natural water sources like ponds, rivers and tube-wells for obtaining drinking water. These sources have become severely saline from seawater intrusion caused by environmental changes and man-made factors including poor water management and shrimp farming. Salinity has already encroached 100 km inland from the Bay of Bengal, and the impacts are projected to be exacerbated by sea level rise due to climate change and excessive groundwater withdrawals from aquifers.

In this situation, salinity intrusion and health hazards of the people of the southern part of Bangladesh need to be on the agenda in the Fifth Consultation of the UN High Level Panel on Water (HLPW) on Valuing Water.

Now, it is imperative to develop and evaluate affordable approaches to providing water with low salt content such as rainwater harvesting. To preserve rainwater and make water salinity free, traditional aquifer system in small scale has been working.  But that is not enough. In this respect, Aquifer Storage and Recovery (ASR)-- a sophisticated water aquifer device to Manage Aquifer Recovery (MAR), could be implemented with the support of foreign donor agencies or countries who are, in fact, responsible for the carbon emission, the major cause of global climate change.

The writer is Assistant Professor, Bangladesh Institute of Governance and Management (BIGM). [email protected]