Securing a watertight future

Sri Lanka, though not as critically threatened by climate change as several other South Asian countries, will face increasing pressure on its water resources in the coming years, according to experts at a conference hosted by the International Water Management Institute (IWMI) in Colombo.

The conference convened in order to share information and promote plans of action to cope with the evolving threats climate change poses to South Asia. This region, according to several reports, supports 25% of the global population with only 5% of the world’s water resources.

As the world warms, variability in the intensity and distribution of rainfall, as well as instances of extreme weather events, will increase. The risks posed by floods and droughts, along with surface and groundwater contamination, will grow with global warming, according to the report “Climate Change Science, Knowledge, and Impacts on Water Resources in South Asia: A Review.”

Distinguished panel of speakers at the bregional conference

Rising sea levels, according to the report, will cause salt-water intrusion into coastal rivers, drawdown of groundwater resources, and reduced recharge of coastal aquifers. These threats, coupled with increasing inconsistency of the monsoons, might combine to decrease agricultural productivity, endanger ecosystems, and contaminate drinking water sources.

Water issues the country is facing

While those at the conference concentrated their efforts on outlining potential future difficulties in South Asian water management, there were also many experts intent on illustrating the water issues Sri Lanka is presently facing.

The problems the country is encountering range from the those made by people, such as drawdown of groundwater, pollution of rivers and streams, deforestation, and sand mining, to dealing with issues of access and distribution of water.

The issue of water management is crucial, as access to clean, affordable water is necessary to socio-economic development. Insufficient distribution and overall lack of water can exacerbate political and social issues. Because of this, it is essential that Sri Lanka protects its water resources, in order to continue its economic development and efforts of reconciliation.

Sanjiv de Silva, a researcher at IWMI, highlighted one daunting water management issue: “Sri Lanka thinks of itself as water rich, but one third of the country is a dry zone.” The island is split into three zones: the Southwestern wet zone, the intermediate zone that includes the Central Highlands, and the dry zone, which includes the entire Northern and Eastern sections of the country.

Though Sri Lanka is not considered water scarce, there is a distinct problem of resource distribution.

While the Western Province, nestled in the wet zone, often faces flash flooding, the rest of the country experiences about eight annual droughts, according to the “Climate Change Science” report.

As demand for water grows both in the industrial and agricultural sectors, Sri Lankans face daunting problems in accessing sufficient water resources.

Because Sri Lanka does not possess an efficient, cheap method for transporting water from wet areas to dry ones, much of the focus on improving access to water for those in dry zones has centered on storing it for long periods of time.

Need to restore small village tanks

One such strategy for water storage in rural areas looks to the past for inspiration for the present.

“There are 25,000 small village tanks in this country. Many have fallen into disuse, but we need those tanks now. With climate change, we need everything we can have for storage,” said Kusum Athukorala, senior advisor to the Sri Lanka Water Partnership and chairperson of Network of Women Water Professionals (NetWwater).

These tanks have historically helped people in the dry zone, an area that receives three months of intense monsoonal rainfall and little other precipitation, store water from the seasonal rains. In the past, these tanks helped cover both agricultural and drinking water needs.

They also provided some protection from seasonal flooding. The tanks allowed for irrigation-fed agriculture during dry spells and rain-fed agriculture during the monsoons.

This system is extremely efficient, does not require the transportation of water, and allows for direct access by farmers. Furthermore, the improvement of this system would improve socio-economic development in rural areas of the dry zone.

“Water storage makes rice crops possible, and as demand grows and surface irrigation becomes insufficient, the restoration of tanks will be important for the continued cultivation of rice,” said de Silva. He also mentioned the rice crop failures of 2013 and 2014 due to decreased monsoon rainfalls.

The expansion of rice farming in recent years has put a strain on surface water resources, as rice is a very water-intensive crop, and more farmers are turning to extracting groundwater from tube wells, boreholes, and pipe systems in order to support their rice farming.

This system of tapping groundwater in order to farm rice however, isn’t sustainable, according to de Silva. Many farmers have, after facing water shortages for years, turned to cultivating other crops, such as fruits and vegetables, which tend to need less water than rice.

Voting on next steps - the conference ends with an informal vote on 8 potential recommendations to move forward water management across South Asia. Photo credit: Shaoyu Liu

An improved system of storage tanks would also mitigate the issues of variable rainfall, rapid runoff, and evapotranspiration, or the evaporation of water from the soil and loss of water from plants. The big problem however, is that the tank system was built to store water for vastly fewer people, so the system must be renovated and expanded.

Sri Lanka uses 87% of its water resources for agriculture, and a lot of water would be saved by improved rainwater harvesting and storage techniques, according to Athukorala.

Impact of deforestation and sand mining

While people cannot control the pattern and intensity of rainfall, they can influence practices that lead to water degradation, such as the continued practice of deforestation.

“Unplanned cutting of forest cover has an impact on stream flow and flash flooding. An extreme rainfall event might multiply downstream flooding,” said Dr. Alan Nicol, theme leader of governance, gender and poverty at IWMI. Forests soak up excess rainwater and keep it from entering rivers. With fewer trees to absorb large amounts of rain water, the incidence of downriver floods will increase, according to multiple sources.

On top of this, trees play a critical role in anchoring soil in place. Deforestation, then paves the way for increased landslides. “High intensity rain, coupled with deforestation, is proven to cause land and mud slides,” said Dr. Nicol. 67% of the Badulla District, according to Kusum, is landslide prone.

Yet another problem posed by deforestation is the concurrent destruction of catchments, or areas that collect rainfall and funnel it to streams and then rivers. “Mountain springs are no longer running in large areas in Sri Lanka,” said Kusum. Vital sources of surface water, catchments supply many throughout the country with drinking and irrigation water. As these are being destroyed, people are increasingly turning to the extraction of groundwater to make up the difference. This further stresses groundwater and leads to the drop of the water table.

Another growing threat to Sri Lanka’s water is the expansion of river sand mining. Swift development has led to an upsurge in the demand for sand as a construction material. Large-scale mining at the mouths of rivers, such as has occurred at the Kelani River, has caused a severe salinity intrusion, which is currently adversely affecting the Colombo area, according to Kusum.

According to the The Water Integrity Network’s report “Curbing Illegal Sand Mining in Sri Lanka,” many purification plants have been moved to affected areas in order to desalinize river water. This is an extremely costly process, and the public has footed the bill while private mining companies continue to prosper.

Increased salinity degrades the quality of both surface and groundwater and damages crops if used in irrigation. Furthermore, mining contributes to the erosion and eventual collapse of riverbanks, which in turn, can increase the chances of flooding. According to a paper by Ranjana U.K. Piyadasa, sand mining over the past twenty years in the Walawe River has “deepened the riverbed by an average three to four metres.”

While some sand mining is carried out legally, there is widespread illicit mining that is done without any scientific review. Many individuals mine sand in order to make a living, but their actions influence the livelihoods of farmers and others who depend on the land.

Though the experts at the IWMI conference focused on various issues regarding water management in Sri Lanka, they all agreed that better planning and coordination is necessary to parry the growing threats to the country’s water, posed by climate change.

Dr. S. Pathmarajah of the University of Peradeniya, highlighted the necessity of improved organization: “There are 30 or so institutions dealing with water, but there is no central policy. We need more communication because right now, we waste a lot.” Creating a policy for managing water resources however, has proven difficult, as Sri Lanka has a range of climates that pose distinct problems.

Plans to conserve water in the mountains are often drastically different from those concentrated on the coasts.

Furthermore, Dr. Nicol pointed out the inherent social issues facing a comprehensive water policy. “Water management is a cultural, social landscape that is deeply imbedded in particular social structures. Changing things can be difficult.”

Despite these challenges, Athukorala argued for the importance of a far-reaching water policy. “We need to understand that we are facing a crisis. Whether we are having floods or droughts, it’s the two sides of the coin. We need to have something like a water council that will have a bird’s eye view of everything in water.”

As Sri Lanka continues on its path of socio-economic development and reconciliation, it will be important to manage the risks inherent in climate change and man-made water pollution. After years of conflict, Sri Lanka needs its water in order to rebuild and flourish.