Winding through Wilderness: Free-flowing Rivers of Planet Earth
Rivers are lifelines of every civilization and have been so since the beginning of time. Yet at present, the planet is losing free-flowing rivers as a little more than one-third of the longest rivers remain unobstructed by human-made changes.
What are free-flowing rivers?
Rivers largely unaffected by human-made changes to their flow and connectivity, carrying water, silt and other natural materials and unobstructed from source to sink are free-flowing rivers. These rivers can swell or shrink naturally, host river dolphins and migratory fish, replenish groundwater reserves, and flow at an organic volume and rate. Free-flowing rivers are the freshwater equivalent of wilderness areas. These rivers are ecologically important, help sustain biodiversity as well as reduce impact of droughts and floods.
However, just 37% of the world’s longest rivers remain unimpeded over their entire length, according to a study published in Nature. The researchers looked at 246 longest rivers across the globe (longer than 1000 km) and found that just 23% of these rivers, that eventually emptied into oceans, are free-flowing. The untouched rivers are mostly prevalent in remote areas, regions difficult to exploit, less developed locations or rivers too large to be developed by current technology. Examples are, the Arctic, Congo region, Myanmar etc. In densely populated areas, rivers like Irrawaddy and Salween, remain free-flowing.
Causes of Obstruction to Free-flowing Rivers
- Economic development, especially infrastructure, is the culprit that obstructs smooth flow of rivers.
- Dams constructed at wrong places change the course and flow of a river, creating havoc in migratory cycles of biodiversity that depends on these for food, reproduction, or habitat. There are approximately 60,000 large dams worldwide with about 3700 more in tow.
- Roads built alongside a floodplain prevent rivers from naturally swelling or shrinking throughout the year, especially when protected by a big flood wall.
- Due to construction of buildings and farms, aquifers are disconnected from rivers, and cannot replenish causing water scarcity in the neighbouring regions.
Are Rivers Being Choked in Protected Areas Too?
A study in Conservation Letters states that globally 509 dams are planned or under construction within protected areas with 1249 large dams already present in these regions. About 33% of all planned hydropower in the European Union is in protected areas raising red flags. It is because dams negatively impact livelihoods of locals, impede species movements, change sediment flows to downstream deltas and floodplains, and may cause droughts or floods in the near future. Researches have evidence that between 1970 and 2014, about 83% decline has been seen in populations of freshwater vertebrates. A paper published in Nature also found that dams are one of the main reasons for a 76% collapse in freshwater migratory fish populations since 1970.
Status of Free-flowing Rivers in India
Unfortunately, India does not have any legislation to protect free-flowing status of any of its rivers. With the exception of Bhagirathi River (100 km long), declared an eco-sensitive zone under the Environment (Protection) Act, 1986, following the fast-unto-death crusade of Dr. G.D. Agarwal, there are no explicitly protected free-flowing rivers in India. Protection, if any, is incidental.
Explore WWF Free Rivers
The WWF Free Rivers augmented reality app is an incredible virtual world where a user meets people and wildlife living in a region. This app puts an entire landscape up front, in focus, so users can share an in-depth, interactive story. They can learn how free-flowing rivers form an important aspect in sustaining biodiversity. Stimulating rainy seasons to see healthy adaptation of a river towards excess water is also one of the aspects in this app. Users can build dams and notice differences in river volume and flow. They can also use an energy combination that keeps a river connected while satisfying increasing energy demands. The app can be downloaded from Apple Store or Google Play.
A Dependable Approach
Skill lies in thoroughly comprehending pros and cons of a project before initiation. Preliminary investigations regarding accessibility of a hydropower/road/building plan, blueprint of areas affected, survey regarding tangibility of schemes involved, modelling techniques predicting course of rivers for at least a generation, panel discussions with stakeholders and financial consistency need to be properly handled by the authorities before introducing major irreversible changes to the environment. Novel approaches and sound policy will always come in handy when deciding the future of our free-flowing rivers.