TriplePundit • What Happens When Communities Turn to Nature to Fight the Effects of Drought?

The past few years have seen some of the most severe droughts on record. Global hotspots are suffering not just water shortages but food and power shortages, as well. While other natural disasters like floods and hurricanes may garner a lot of attention for their immediate impacts, droughts take their toll over time — earning less attention despite causing greater death tolls overall. From 1970 to 2019, 34 percent of deaths from natural disasters were caused by drought, despite droughts only making up 6 percent of all natural disasters during that timeframe.

As droughts become more common and last longer, they increase the social and economic pressures on already vulnerable communities. Countries in Southern and Eastern Africa have been hit especially hard, despite contributing little to the greenhouse gas emissions driving climate change and intensifying droughts. Tens of millions of people on the continent have been displaced and face hunger and malnutrition. Tens of thousands more have died, according to a report from the United Nations Convention to Combat Desertification (UNCCD) and the University of Nebraska National Drought Mitigation Center at the University of Nebraska.

As communities brace for the future, they’re using nature to mitigate the impact. Helping water find its way deep into the ground can jumpstart nature’s water-storing abilities, allowing communities to stretch the water supply from spotty rainstorms over the long, dry months.

Helping nature do what it’s meant to do

Nature-based solutions for drought are all about restoring and protecting nature’s ability to cycle water. By proactively managing ecosystems for drought, natural systems are better able to store, filter and release water in a sustainable way, said Daniel Tsegai, editor of the U.N. report and program officer at the Secretariat of the United Nations Convention to Combat Desertification. In essence, it means protecting and reinforcing watersheds, and restoring soil and wetlands so they can store precipitation when it does come. This creates a buffer for when the rains eventually run dry.

Sand dams are one way communities reinforce watersheds using natural systems. By bolstering seasonal rivers with small dams, moisture is encouraged to soak into sandy riverbeds instead of evaporating. This helps filter the seasonal rains into groundwater stores, recharging aquifers and providing water during the dry season and in the event of a drought.

“[This] is very, very successful, small-scale water harvesting,” Tsegai said.

About 130 sand dams are built each year in Kenya, with similar structures used in India, Brazil and Angola, according to The Water Project. These basic stone or concrete walls are constructed across seasonal riverbeds, so when rain comes and the rivers begin to flow, the water sits and slowly soaks into the sandy bottom instead of overflowing onto the surrounding land, where it cannot penetrate the soil and evaporates instead. This recharges the groundwater, which can be accessed during dry seasons through hand-dug wells. If constructed properly a sand dam can last over 100 years, according to The Water Project.

Restored groundwater sets off a chain reaction for groundwater collection. Sand dams were found to improve soil health and support farmers in establishing nurseries, planting drought-tolerant fruit trees and growing produce that protects against food insecurity. In a study of sand dams installed by communities in Kenya, households were planting trees at more than twice the rate they did before the dams, and the rate of residents skipping meals or reducing portion sizes due to food availability reduced from 100 percent to 11 percent.

By increasing the amount of moisture retained nearby, the crops and trees communities plant are more likely to survive. And planting more drought-tolerant trees further increases the land’s ability to retain moisture by slowing rain runoff and creating a healthier, spongier soil surface.

On average, communities with sand dams can access water locally for an additional four-and-a-half months of the year when they would otherwise have to fetch it at a distance and use extreme rationing. In drought years, when less groundwater is restored, they are still able to extend their access to water for an average of almost four months.

Cost effective, but not a magic bullet

“Nature-based solutions are cost-effective,” Tsegai said. “ If you invest $1 dollar on nature-based solutions to drought, you get $27 in return, so the benefit-to-cost ratio is very, very high, and the economics of it are very important.”

Still, he is quick to point out that nature-based solutions are not a magic bullet against drought. Even when options are cost-effective, financing can be hard for developing countries to come by. There is also the matter of how time-intensive it can be to scale up nature-based projects.

“It takes years, sometimes even decades, before you see some kind of real hydrological benefits, so it’s not a rapid fix,” Tsegai said. “It is definitely location-specific. It’s not one size fits all.”

Projects need to match the local soil, agriculture and water systems, he said. Done incorrectly, nature-based solutions could do more harm than good. Even in the best-case scenario, they can’t stand alone and need to be integrated with drought monitoring systems, early warnings, emergency responses and dam systems to supply collected water.

“When there is this very extreme climate change, like what we see with the intensive frequency of droughts, solutions alone are not enough,” Tsegai said. “Drought is increasing by more than 30 percent since 2000, and it’s going to get even worse everywhere. We can definitely not depend only on nature-based solutions to fully substitute for any engineered water supply.”