Santiago de Chile has to adapt to the water scarcity

AFP, published Wednesday, April 20, 2022 at 2:49 p.m

A decade of drought has prompted authorities in Santiago, Chile, to consider how best to avoid water rationing: savings, planting native vegetation, and restriction plans to try to prevent continued shortages.

Central Chile has been plagued by a drought for more than a decade. The 71% rainfall deficit in 2021 made the southern winter in this region the driest in the 21st century (43% nationwide), according to the Chilean Meteorological Directorate.

Equally alarming are the forecasts for the new winter approaching with light rain forecasts around the capital, a consequence of climate change.

Without adequate rainfall, key reservoirs, lakes and rivers that feed Santiago’s 7.1 million residents are at critical levels, and authorities are preparing for the last resort: rationing.

“We can’t let the rain fall. It’s not up to us, but we can prepare for an extreme situation. said Santiago Governor Claudio Orrego last week, announcing the implementation of a three-stage alert protocol.

The first two relate to reducing non-essential uses and lowering the pressure in the taps. The final tier, “Red Alert,” involves strict “rotating” rationing by sector of the city for a maximum period of 24 hours.

Although Santiago’s population has tripled in 50 years, domestic use accounts for only about 10% of the water consumed in Chile, agriculture 70% and industry 20%.

– native species –

Every day, the agronomist Pablo Lacalle observes with concern the decrease in the Mapocho river, which crosses Santiago from east to west for about thirty kilometers. Last year, according to official figures, it fell by 57%.

“For us, it’s a trend. It’s like reading the newspaper in the morning, we have an idea of ​​what’s going to happen throughout the day,” as for water needs, explains Mr. Lacalle, Head of Water Resources at Santiago Metropolitan Park (parquet).

This 737-hectare park nestles on San Cristobal Hill, one of the highest in Santiago, overlooked by more than six million visitors each year.

Its vast lawns are irrigated with water from the Mapocho River, which is also the main irrigation system for the many private gardens in the affluent neighborhoods of eastern Santiago.

“We have to plan our irrigation capacity for the park because we have an 87% water deficit compared to previous years,” explains Mr. Lacalle.

Strategies to reduce the park’s water needs have already been implemented and “the exotic forest is being replaced by native forest,” as on the north slope, where 100,000 trees have been planted in three years, explains Parquemet director Eduardo Villalobos.

These considerations would have allowed him to reduce the risks of “drought and fires”.

Initiatives are being started all over the city to save water, which has become a precious commodity.

Architect Joaquin Cerda created the Native Sidewalks project to replace the grass that covered around 150 square meters of sidewalks with 25 different native plants in the residential area of ​​Pedro de Valdivia Norte.

“These are species that are used to the Mediterranean climate of Santiago and to prolonged periods of drought,” he told AFP.

“We water once a week for half an hour and use a drip irrigation system,” he says, noting that “water usage has been reduced to less than a tenth of what ‘she used to be’.

Water is also at the heart of the ongoing debates surrounding the drafting of Chile’s new constitution, which will be submitted for adoption by referendum in September.

If water is a national public good whose concession is entrusted to the private sector, members of the Constituent Assembly on Monday passed an article stating that “it is an inalienable common good” to be managed on a participatory, supportive and fair basis .