River Health

The river is a complex ecosystem with endless bio-geo-chemical interactions. Inside this large system, nature has established the mutual balance between chemical and physical components, organic and inorganic substances, micro and mammoth organisms.

In common belief, we consider the river to be a stream of fresh water. The river and its basin together make up the body of the river simultaneous with the human personality, with the holistic view of mind and body. The biggest representative of river health is the condition and population of indigenous species of fish and other living organisms. River Health can be framed as ‘The propensity of an aquatic ecosystem to support and maintain key ecological diversity without hampering the habitat within the region.’

If we compare the health of the river system with the equivalent examples of the human body, then the stream of the river is like the main artery of the human body. If the main artery is healthy, without any blockage and a sufficient amount of blood is transmitted through it. A person can be assumed to be healthy. Similarly, if there is a sufficient amount of water flowing in the mainstream, it can be said that the river is healthy. The health of the main artery is connected with capillaries and veins. Similarly, the health of the main stream of a river depends on its tributaries and distributaries. The quality of blood in the human body is tested on various parameters, such as hemoglobin level, platelets count, etc. Similarly, river water is also tested on various chemical and biochemical parameters like dissolved oxygen, biological oxygen demand, pH of water, total dissolved solids, etc.
One major difference here is that, unlike humans, a scale cannot be fixed for rivers. The mineral salts present in the water of a river and the chemical properties of the water are determined by the overall natural, geographical and ecological composition of the river basin and may differ from one river to another Just as the lungs help in respiration in the human body, river sand plays the role of lungs in the context of a river. Human receives water and nutrition from his mouth, the wetlands, and the forests of the river basin act as the mouth which feed the river with water.
The biggest representative of the health of a river is its fauna. If the population and position of the tertiary level consumers in the food chain of the river ecosystem is correct, then it can be assumed that the health of the river is in good condition. For example, in the context of Ganga, the tertiary consumer is the Gange dolphins. Macro invertebrates and various species of fish are found in different sections of the river which are the primary, secondary, and tertiary consumers respectively in the food chain. Their presence in the natural habitat is the major representative of the health of the said river stretch. If these aquatic animals are in an environment conducive to habitat, nutrition, growth, and reproduction, then it can be considered that the health of the river is in good condition.

The actual state of health of the river can be reflected by the indigenous species inhabiting the said river and not by the exotic species which are being introduced for commercial gain.

In this criterion, river water quality, vegetative ratio, nutrients, minerals, flows, slopes, morphology can be found in assessing the health of the river. For example, if there is a change in morphology, then the habitat of some organisms will be affected. If the water quality drops, the survival of some species will be threatened.

cGanga’s river health assessment and improvement studies focus on four key areas: geomorphology, hydrology, water quality, and biological profile.

In addition, river health is also connected with natural and manmade surface and subsurface water bodies in the basin, and particularly in the river-floodplain. Thus cGanga’s river health assessment and improvement studies cover six additional areas: subsurface or groundwater, wetlands, lakes, reservoirs, canals, rivulets, and streams.