World Water Day 2022: what are healthy watersheds and why are they important? | The Weather Channel – Articles from The Weather Channel


March 22 is World Water Day, a time to draw attention to our most critical natural resource and sadly most recent trends are alarming. The past year has seen record water shortages in the western United States, Brazil, Kenya, southern Europe and many other places. Catastrophic floods affected most Indian states in 2021, as well as Germany, China, Australia, Malaysia and South Sudan. Water pollution continues to cause millions of premature deaths every year in India and elsewhere. These water crises are often summed up as “too much, too little or too dirty”. But these are just symptoms of a larger syndrome: unhealthy watersheds.

A watershed, or drainage basin, refers to the area of ​​land that collects and drains rainfall to an outlet – a stream, a lake or the sea. A massive river basin like the Ganges is a system of connected watersheds. Human activity in these watersheds, such as clearing forests and wetlands to grow crops, building too many dams, or dumping pollutants into waterways, all have a negative impact on health. watersheds. Like individual water droplets in the river, each activity may seem insignificant on its own, but cumulatively the impacts can trigger fish kills, disease outbreaks, crop losses and more.

Ganga River in Kolkata.  (Kuntal Chakrabarty/IANS)

Ganga River in Kolkata.

(Kuntal Chakrabarty/IANS)

Watersheds have some ability to “heal” themselves by filtering pollutants, absorbing flood waters and resisting droughts. Yet many watersheds are being pushed beyond their limits, resulting in these negative impacts for the humans and wildlife that depend on them.

So what does it mean to have a healthy watershed? To begin with, a healthy watershed must have healthy, intact ecosystems. Forests, wetlands, grasslands and waterways provide so-called ecosystem services, such as regulating the quantity, quality, timing and flow of water, and providing of a habitat for fish, birds and thousands of species that we appreciate and appreciate. As these ecosystems degrade, their ability to continue to provide benefits diminishes, and in most cases they cannot be easily or effectively replaced by technology.

Maintaining a healthy watershed involves balancing protecting natural ecosystems with ensuring humans can access benefits such as clean water and protection from floods and other hazards, not to mention maintaining the spiritual and cultural importance of so many bodies of water.

Flamingos invade a wetland near Thane in Mumbai.  (RIZWAN MITHAWALA/YOI, BCCL, Mumbai)

Representative picture

(Rizwan Mithawala/TOI, BCCL, Mumbai)

Why is it important to have this watershed perspective? First, many of the relevant decisions in a watershed involve trade-offs. For example, pumping groundwater from an aquifer can help irrigate crops (and improve farmers’ livelihoods), but over-extraction can trigger land subsidence, soil salinization, and even the drying up of streams. of water. Everything is connected in a watershed.

It’s the same for people who live in the watershed because everything flows downstream. Careful stewardship of an upstream watershed provides benefits to downstream communities and watersheds. Conversely, overuse of water, excessive dumping of waste, and removal of native vegetation can all lead to crises in remote communities connected by the flow (or lack) of water.

Focusing on improving watershed health can help make large and overwhelming problems a little more manageable. The health of the Ganges or any other major freshwater system must begin with local improvements, watershed by watershed. Goals can be set locally, such as restoring a forest upstream, helping a specific fish species to recover, or installing more permeable surfaces (green roofs, swales) to manage stormwater.

Hussain Sagar Lake in Hyderabad, Telangana.  (Rama Moorthy P/TOI, BCCL, Hyderabad)

Hussain Sagar Lake in Hyderabad, Telangana.

(Rama Moorthy P/TOI, BCCL, Hyderabad)

Individuals, local governments, civil society organizations and businesses can easily find opportunities to improve watershed health close to home. It also provides a positive outlook, rather than waiting for the next water crisis as motivation – public health studies have consistently shown that fear, as a motivational tactic, is much less effective in changing behavior than to promote healthy behaviors.

Healthy watersheds always depend on supporting policies and technologies. Providing reliable access to clean water and sanitation services should be a top priority, as this will reduce pressures on urban and peri-urban watersheds and ensure that all people share in the benefits rather than dealing with impacts on human health from unhealthy watersheds. Governments must re-examine policies that compromise watershed health, such as promoting “thirsty” (water-intensive) crops in places that do not have enough water to meet all needs in a sustainable way. sustainable.

And finally, as we already see, climate change impacts the “too much, too little” part of the water crisis. A healthy watershed will not be immune to excessive rainfall and drought, but it will be more resilient. Our best insurance against an uncertain future climate is to protect and restore our watersheds and all the benefits they provide.

Derek Vollmer is Senior Director of Freshwater Science at Conservation International, where he leads a team of hydrologists, ecologists and freshwater biologists to develop tools and provide technical support for water resource management .

This article is a guest column reflecting the views of the author and does not necessarily represent the official views of The Weather Channel. The article has been partially edited for length and clarity.


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