World Water Day 2022: What Are Healthy Watersheds, and Why Do They Matter?
Sustainable Development Goals: 6
- SDG 6 - Clean Water and Sanitation
March 22 is World Water Day, a time to focus attention on our most critical natural resource and, unfortunately, most of the recent trends are alarming. The past year has witnessed record-breaking 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 in India and elsewhere each year. These water crises are often summarised as “too much, too little, or too dirty”. But they are all merely symptoms of a broader syndrome—watersheds in poor health.
A watershed, or drainage basin, refers to the area of land that collects and drains precipitation to an outlet—a stream, lake, or the sea. A massive river basin like the Ganges is a system of connected watersheds. Human activity in these watersheds, like clearing forests and wetlands to grow crops, building too many dams, or releasing pollutants into waterways, all negatively impact watershed health. Like the individual droplets of water in the river, each activity may seem to be insignificant on its own, but cumulatively the impacts can trigger fish kills, disease outbreaks, crop losses and more.
Watersheds have some capacity to “heal” themselves by filtering pollutants, absorbing floodwaters, and withstanding droughts. Yet, many watersheds are being pushed beyond their limits, leading to these negative impacts for humans and wildlife depending on them.
So, what does it mean to have a healthy watershed? To start with, a healthy watershed needs to have healthy, intact ecosystems. Forests, wetlands, grasslands, and streams provide what are referred to as ecosystem services, like regulating the quantity, quality, timing and flow of water, and providing habitat for fish, birds, and thousands of species we enjoy and appreciate. As these ecosystems become degraded, their ability to continue providing benefits declines and in most cases, cannot be easily or efficiently replaced by technology.
Maintaining a healthy watershed involves a balancing act between protecting natural ecosystems and ensuring that humans can access benefits such as clean water and protection from floods and other hazards, not to mention retaining the spiritual and cultural significance that so many water bodies hold.
Why is it important to have this watershed perspective? First is that many of the relevant decisions in a watershed involve tradeoffs. For example, pumping groundwater from an aquifer may help irrigate crops (and improve farmers’ livelihoods), but over-extraction can trigger land subsidence, salinisation of soils, and even the drying of streams. Everything is connected in a watershed.
The same goes for people living in the watershed because everything flows downhill. Careful stewardship of an upstream watershed ensures benefits to communities and watersheds downstream. Conversely, overuse of water, excessive waste dumping, and removing native vegetation can all lead to crises in distant communities connected by the flow (or lack) of water.
Focusing on improving the health of watersheds can help make big, overwhelming issues a little more manageable. The health of the Ganges or any other major freshwater system has to start with local improvements, watershed by watershed. Goals can be set locally, like restoring a headwater forest, helping a specific fish species recover, or installing more pervious surfaces (green roofs, bioswales) to handle stormwater.
Individuals, local governments, civil society organisations, and companies can all easily find opportunities to improve watershed health close to home. This also provides a positive vision, rather than waiting on the next water crisis as motivation—studies in public health have regularly shown that fear, as a motivational tactic, is far less effective at changing behaviours compared to promoting healthy behaviour.
Healthy watersheds still depend on supportive policy and technology. Providing reliable access to clean water and sanitation services should be a top priority because this will reduce pressures on urban and peri-urban watersheds and ensure that all people are sharing in benefits rather than dealing with the human health impacts of unhealthy watersheds. Governments need to reexamine policies that undermine healthy watersheds, like promoting “thirsty” (water-intensive) crops in places that do not have enough water to meet all needs sustainably.
And finally, as we are already witnessing, climate change impacts the “too much, too little” part of water crises. 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 for freshwater science at Conservation International, where he leads a team of hydrologists, ecologists and freshwater biologists in developing tools and providing technical support on water resources management.
This article is a guest column reflecting the author’s opinions and does not necessarily represent the official views of The Weather Channel. The article has been partly edited for length and clarity.