This post was written by Andrea Becerra.
From too much water to not enough, this critical resource presents unique challenges in the Metropolitan Region (MR) of Chile, the hub of the country’s bustling capital and nearly half of the Chilean population. A recent report by NRDC highlights water management solutions that address floods and droughts, two seemingly divergent issues that already take a toll on communities in the region.
A parched land dependent on dwindling resources
Chile’s drought is not showing any signs of ending. The region has experienced the driest decade in recorded history, and the MR is one of the most impacted areas. Loss of rain, compounded by high water demand, has led to an agricultural emergency declaration in 17 communes in the MR just this year. Part of the problem is that the region’s aquifers are being depleted at a faster rate than they recharge. And while reserves below the ground are being pumped dry, Chile’s rich glacial reserves that pepper the Andes mountain range in white are increasingly threatened by rising temperatures associated with climate change and human activity, including mining. Scientists predict that by 2070, the glacier-fed Maipo basin, which supplies 80 percent of the region’s potable water, will experience a 40 percent reduction in water flow due to loss of precipitation and glacial retreat. Precipitation in the MR’s Andes mountains has fallen 3 cm every 10 years, according to the Chilean Antarctic Institute. This has contributed to 8.54 to 15.14 gigatons of glacial retreat—this would have been enough to supply all of Chile’s water needs for the next 14 years.
Southwest of Santiago, the dried-out Aculeo Lake has become a symbol of the region’s ostensibly endless drought. The etchings of a lake can be traced on the large, dry stretch of land, where less than five years ago an expansive and pristine lake drew tourists escaping the busy metropolis to camp and swim in the clear water. The effects on the surrounding community have not been documented, though the tourism industry has undoubtedly been devastated. Anecdotally, in NRDC’s conversations with locals who work in tourism and have lived in the region for decades, there has been a 50-70 percent reduction in traffic into the lake region on weekends and holidays and over 5,000 people have lost their jobs. Climate change, housing development, and overconsumption by the agriculture industry have all been blamed in varying degrees by different experts. It’s hard not to see this phenomenon as a window into the region’s future trials with water.
Meanwhile, flooding is still a growing risk
Ironically, as the region grapples with a water-scarce future, Santiago is expected to see more floods every year. Urbanization coupled with loss of vegetation, and higher-than-average temperatures due to climate change leaves the MR increasingly exposed to floods. A mere 5 mm of rain in the outskirts of Santiago in 2017 caused catastrophic floods and mud and landslides, cutting water supply for over six million people in the MR and blocking four bridges, leaving over 1,000 people trapped on a mountainside. According to the United States Geological Survey 5 mm of rain is considered a moderate shower. So why were the floods so catastrophic? For one, fires that had ravaged the region in previous weeks caused rampant deforestation, killing large swaths of trees that help retain water and reduce erosion. And second, parched soil from the prolonged drought had lost its absorbency. In fact, soil during a drought can become hydrophobic, actually repelling water—meaning that droughts interrupted by storms can often lead to floods.
Land use is also impacted by the region’s growing population. Forty percent of the country’s population already lives in the MR. In a business-as-usual scenario, the region’s population is expected to increase by around 20 percent by 2050, to 8.5 million. To accommodate this growing population, Santiago’s geographical limits have expanded, replacing natural landscapes and agricultural land with paved roads, residential buildings, and commercial centers. There is a direct link between the loss of green spaces and an increase in surface water runoff and flooding events in the MR. Heavy downpours coupled with impermeable city streets mean that water has nowhere to go during storms. If Santiago’s current rate of sprawling urbanization continues without any change in the approach to construction, scientists at the Helmholtz Centre for Environmental Research predict that floods will be increasingly severe in both area covered and depth.
Impacts will get worse if nothing changes
While the picture seems bleak, we are encouraged by the many solutions being implemented worldwide. In collaboration with Adapt Chile, NRDC recently released the report “A New Course: Managing Drought and Downpours in the Santiago Metropolitan Region,” which dives more deeply into the challenges of drought and flooding mentioned here. The report also presents key solutions that have already been tried and tested in other parts of the world facing similar challenges, including Australia, China, parts of Europe, and the United States. There are green infrastructure solutions that not only save money but also increase soil moisture, water filtration, and reduce flooding risk, innovative farming techniques such as cover crops and no-till that have reaped positive yields in drought-prone regions, and examples of collaboration across multiple nations that demonstrate cross-sector coordination along the Maipo basin is possible.
Chile is well-positioned to implement new water management strategies and advocate for change and a new way forward. As host of the next COP 25, home to the largest fleet of electric buses in Latin America, and with a former president who was named a UN Environmental Champion, the country is teeming with environmental solutions. The resolve to act is there, water is simply a new frontier.
Andrea Becerra is a consultant for NRDC focusing on urban and rural water management issues in Latin America.