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Floods and droughts could be better managed with improved water storage strategies

Originally published on the CGIAR Research Program on Water, Land and Ecosystems (WLE) blog.

In a live-streamed science seminar [...], water expert Vladimir Smakhtin will talk about the issues and potential solutions to extreme water variability such as floods and droughts. This blog will give you a further introduction to the seminar topic :

Watch the live-streamed seminar

Get the presentation from the seminar : Managing water resources variability for improved food security and livelihoods

Here’s the problem with extreme water variability : either there’s too much water or too little.

“Variability, which has increased with climate change, heightens the risk of both floods and droughts,” says Vladimir Smakhtin, a theme leader for the International Water Management Institute (IWMI) and the CGIAR Research Program on Water Land and Ecosystems, led by IWMI. “The inability to control rainfall runoff or reduce the risk of drought lead to high levels of food insecurity and poverty.”

Annual damage from floods and droughts recently reached $165 billion — the lion’s share from floods — and is projected to nearly triple to $450 billion by 2030, according to an international disaster database. Livelihoods of millions of people worldwide are affected by floods and drought.

There is a silver lining. Scientists today increasingly can identify, map and characterize “hot spots” prone to flood and drought risks based on an unprecedented amount of data, and climate projections.

Learn more : Global flood hotspots being identified

That, in turn, enables investments to be targeted to the water storage options best able to mitigate floods and droughts, and improve irrigation and farmer livelihoods. (Water storage is widely considered to be a key way to tackle flood and drought risks).

“In the past, water resource planning has tended to focus on large dams but dams are just one of a range of possible water storage options,” Smakhtin says. “A more flexible approach is to develop storage portfolios that fit the needs of a given location.”

Depending on the location, a water-storage portfolio might combine human-made and natural structures such as large and small dams, lakes, on-farm ponds, and even underground storage. The goal is to boost economic development while protecting important ecological systems.

IWMI researchers increasingly are investigating underground water storage facilities as an option to “tame” floods and soften long droughts.

For example, a ’desktop’ study by IWMI researchers estimates that an additional 270,000 hectares of land could be irrigated through underground water storage facilities serving the Chao Phraya River Basin in Thailand. Existing water storage facilities are inadequate for farmers to reach their cropping potential during the dry season and devastating floods have been an issue during the monsoon season.

Floods could be reduced by harvesting in underground aquifers as much as 25 percent of the rainfall runoff during monsoon season.

Such a system could require 100 square kilometers of land (less than 1 percent of the basin area) and could cost nearly $1 billion. But IWMI estimates that smallholder farmers could generate an additional $150 million a year in income, essentially meaning the system would pay for itself in less than seven years.

Developing this type of storage solution and others for hot spots around the globe will require detailed engineering designs, identifying areas suitable for pilot tests and on-ground experiments, flood forecasting systems linked to farmers and, of course, a commitment by governments and donors to invest.

Daunting challenges, to be sure.

But, looking at it another way, Smakhtin says, “the potential is there to be realized.”

For more information

Source : CGIAR Research Program on Water, Land and Ecosystem (WLE) blog, via CCAFS

Crédits: AK-Project