Water Resource Management: A UDA Persepective
Water is the basic unit of life on Earth. As water touches every aspect of human life such as survival, health, sanitation, agriculture, food, manufacturing, construction, and leisure, management of water resources is of critical importance to humankind. These resources are also becoming scarce due to ongoing climate change and the unprecedented situations in nature that we have never encountered before. As a result, alternative management strategies are sought in order to avoid contamination, pollution, drought, scarcity and setbacks in the management of water resources. This is called Water Resource Management (WRM). WRM activity focuses on exploring, researching, planning, developing and distributing the available water resources. Its key focus areas are:
- Optimization of total water resource usage.
- Preservation and expansion of the existing water sources.
In the context of the Underwater Domain Awareness (UDA) Framework, WRM focuses on :
- Maintaining adequate quality and quantity of ground water for drinking, sanitation, food production and inland water transport.
- Protecting the ecosystem of lakes, rivers and oceans.
- Managing water-related risks such as tsunamis, floods, drought, pollution and contamination.
- Leveraging sustainable use of significant submerged cultural and biological resources.
Focus Areas in Underwater Resource Management
1. Recharging the ground water:
Groundwater recharge is a hydrological process, where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer. Groundwater recharge originates as infiltration at the land surface or beneath a surface water body or water that is temporarily ponded on the land surface. Recharge occurs both naturally and through artificial groundwater recharge. The recharge process is studied in the context of agricultural improvements and groundwater problems.
2. Recharging the ground water:
Reservoir sedimentation is the gradual accumulation of the incoming sediment load from water resources such as rivers. This accumulation is a serious global problem and has severe consequences for overall water management and flood control. The worldwide loss in reservoir storage capacity is reported to be between 0.5% and 1.0% per annum This gradual process of sedimentation eventually fills a reservoir within 50–200 years.The principal causes are anthropogenic activities such as deforestation, and overgrazing. Sediments are classified on the basis of their origin into four types:
- Lithogenous: Sediments come from land via rivers, ice, wind and other processes.
- Hydrogenous: Sediments come from chemical reactions in the water.
- Biogenous: Sediments coming from organisms like plankton when their skeletons break down.
- Cosmogenous: Sediments coming from space, filtering in through the atmosphere or carried to Earth on meteorites.
The sedimentation process is used to reduce this particle concentration in the water. Improved sedimentation also controls the need for additional chemicals. Sedimentation is accomplished by decreasing the velocity of the water to a point at which the particles will no longer remain in suspension and gravity will remove them from the water flow.
Sedimentation is carried out by watershed management, sluicing, diverting floods, flushing, density venting, and dredging.
Rainfall, deforestation, structural interventions and enclosure of water in reservoirs increases the rate of siltation in rivers. This reduces the carrying capacity of rivers and results in floods and loss of storage. Desilting is the process of removing fine silt and sediment from the river to restore its natural capacity, without widening or deepening it.
Since indiscriminate desilting can cause adverse impacts on a river’s ecology and flow, the following broad precautions have been advised by an Expert Committee set up by the Central Government:
- Catchment area treatment, appropriate agricultural practices and river bank protection/anti-erosion activities should be carried out.
- Arrangements should be made to pass the incoming sediment into a river downstream of the dams/ barrage structures to maintain the sediment equilibrium.
- High intensity dredging should generally be avoided and precautions must be taken to avoid deposition of sediment loads within the river; instead, they should be deposited on other suitable land.
- Rivers should be provided with a sufficient corridor for meandering
4. Underwater Acoustics:
Underwater acousticsis a technique of communicating below water levels, Acoustic surveys are difficult and have low data rates because they use acoustic waves instead of electromagnetic waves.
Acoustical applications are as follows:
- Fishery applications such as fish population surveys, classification of fish species and other biota and biomass estimation
- Rain rate measurement
- Wind speed measurement
- Wave velocity measurement
- Water depth measurement
- Seabed classification
- Ocean acoustic tomography
- Monitoring of ocean-atmospheric gas exchanges and gas leaks from the seabed
5. Drought Management
Drought is a slow-onset, creeping natural hazard. When rainfall is less than normal for several weeks, months, or years, the flow of streams and rivers declines, and water levels in lakes and reservoirs fall, resulting in drought. Based on type, drought is usually categorized as Meteorological, Hydrological, Agricultural, and Socioeconomic.
The effects of drought accumulate slowly over a considerable period of time and may linger for years, resulting in a myriad of economic, social, and environmental complexities. Given that 16% of India’s total area is drought prone, annually about 50 million people are exposed to drought, and a total of 68% of sown area is subject to drought in varying degrees. If droughts are not managed through effective WRM they could result in direct losses in agricultural and agriculturally related sectors such as forestry and fishing, apart from losses in the recreation, transportation, banking, and energy sectors.
There is a critical requirement to address the Some key WRM strategies for drought management are as follows:
- Public information and education campaigns
- Management of available water resources such as emergency water banks, overdrafting of groundwater aquifers
- Improvements in water systems such as leak detection, lining of transmission canals
- Emergency sources of supply such as emergency interconnections, drilling new wells
- Water service restrictions on non essential uses of water
- Prohibition of selected commercial uses
- Water rationing
6. Flood Management
A flood is a high level of waterflow that exceeds the natural carrying capacity of a river and occupies the adjoining low-lying land (i.e., the floodplain), which is ordinarily dry. Floods include sea surges driven by winds, tsunamis, inland, and fresh-water floods caused by rain, or melting snow and ice, or by the bursting of human-made structures such as reservoirs. Of all the natural hazards, floods are among the most widespread and most ruinous to life and property, particularly as a large number of people live near water.
Effective flood management strategies should be part of the nation’s disaster management framework. Some important flood management strategies are as follows:
- Diversion of floodways: Floods can be controlled by redirecting excess water to purpose-built floodways, which in turn diverts the water to temporary holding ponds or other bodies of water, where there is a lower risk of flooding.
- Floodplains and groundwater replenishment: Excess water can be used for groundwater replenishment by diversion onto land that can absorb the water. This technique can reduce the impact of later droughts by using the ground as a natural reservoir.
- River and costal defence: In many countries, rivers are prone to floods. Defences such as levees, bunds, reservoirs, and weirs are used to prevent rivers from bursting their banks. Similarly, coastal defences such as sea walls and barrier islands are used to minimise the damage of coastal flooding.
7. Rainwater Harvesting:
Rainwater harvesting is the process or technology used for collecting, conserving conveying and storage of rainwater for various purposes. Rainwater is collected from a roof-like surface and redirected to a tank, cistern, deep pit (well, shaft, or borehole), aquifer, or a reservoir with percolation.
The construction and use of cisterns to store rainwater can be traced back to the Neolithic Age up to 4000 BCE, when waterproof lime plaster cisterns were built by all leading ancient civilisations, especially near the desert areas.
The different methods of rainwater harvesting include:
- Surface runoff harvesting
Advantages of rainwater harvesting are as follow :
- Very cost effective, easy to install and operate, and decreases water demand.
- Promotes both water and energy conservation and optimal uses of water.
- Improves the quality and quantity of groundwater; also reduces soil erosion, storm water runoff, flooding, and pollution of surface water with fertilizers, pesticides, metals and other sediments.
- Maintains the ecological balance.
With proper treatment harvested water can be used for various purposes such as watering gardens, irrigation, and domestic uses. Rainwater harvesting is an effective tool to develop a sustainable urban environment.
8. Salty Groundwater:
Most arid and semi-arid regions contain a high percentage of sodium salts. Such water is dangerous for livelihood and agriculture and creates alkaline soil. Some of the possible solutions to remove salinity are use of gypsum (CaSO4) or molasses, ash, cultivation of salt resistant varieties, and recharging with good quality of groundwater.
9. Watershed Management:
Watershed management refers to efficient management and conservation of surface and groundwater resources. It involves prevention of runoff and storage and recharge of groundwater through various methods like percolation tanks, recharge wells, etc. However, in a broad sense watershed management includes conservation, regeneration and judicious use of all resources within a watershed – natural (like land, water, plants and animals) and human. Watershed management aims at bringing about a balance between natural resources on the one hand and society on the other. Integrated watershed development activities increase soil moisture, reduce sediment yield, and increase overall land and water productivity.The success of watershed development largely depends upon community participation.
Underwater Management Challenges in India
In India, the WRM scenario is still evolving. The total replenishable groundwater resources in the country are about 432 cubic km. As per reliable research reports from the ‘2030 Water Resources Group’, the estimated ‘Water Gap’ for India is an alarming 50%. The following areas need to be addressed:
1. Policy Gaps:
India still has to address policy formulation with respect to WRM. The need of the hour is an all encompassing integrated Water Resources Law that will outline the national and international ownership, control, and use of water as a resource. Current water policies and laws in India are state-based. Thus, states have exclusive powers to regularise all water supplies. Although the Centre formulates water laws, it has no mandate to implement it. In contrast, many countries have adopted comprehensive water laws in answer to the international issues. Therefore, India needs to revitalise effective reforms such as a National Water Framework law; amendments to the Inter-State River Water Disputes Act; the Dam Safety Bill, etc. Conservation of river corridors and water bodies also needs to be taken up as part of the long-term policy and strategy for eco-management
2. Data and Technology Gaps:
India has a vast geographical landscape including hills, plateaus, valleys, and wetlands, and hence, a variety of water data related to geology, soil moisture, evapotranspiration, irrigation projects, wetlands, soil, floods, droughts, coastal and information is necessary.
However, India uses a decentralised and localised mechanism for data collection as water is a state subject and data generating and executing agencies are at the state level.
The Government of India has set up the National Water Informatics Centre (NWIC) to have a nation-wide repository on water resources data from all diverse sources and to provide single window access to all stakeholders. However, state of the art technology, automated water data acquisition systems, uniformity in measurement standards and integrated data are still a major requirement.
3. Human Resources and Capacity Building Gaps
Managing water, especially groundwater, is a complex process and requires active cooperation at the individual and community levels. Water practices also have specific ways based on local culture and practices. Mere academic institutions may be unidimensional; therefore, it is important to work along with community institutions to develop and spread efficient local practices to ensure proper regulation, conservation and to minimize wastage. It is necessary to build the skills of communities and local resource persons who can manage water resources and conservations locally.
Setting up and nurturing world class institutions in the key areas of WRM such as Planning, Regulatory, WRM Research, Data Management, and Community Practices is therefore vital.Trained students (as a part of their curriculum), professionals, scientists, water workers, and volunteers should facilitate water balance in their respective fields and towns.
Thus, capacity building forms the core of underwater management programmes. Care however should be taken while designing large scale capacity building programmes to ensure they do not remain only a one-time training activity during the planning phase. Project based learnings, monitoring the project progress, internships, fellowships, seminars, conferences, exchange of the global best practices, international collaborations among academia, and industry and water research bodies all constitute capacity building activity and should be encouraged.
4. Academia-User-Industry-State Partnership:
Technical institutes or a think tank should be set up in the domain of Underwater Resource Management and should be entrusted to prepare various policy advocacy papers, fiscal and process guidelines such as dredging guidelines, sediment budget, and flood routing studies, which will substantiate various activities and also provide a visionary roadmap for the same. At present more investment is needed in creating sustainable Institutions to make the impact of the WRM initiatives by the states last for longer periods. This is particularly important in the context of groundwater, which provides 90% of rural India’s drinking water, 75% of irrigation water, and 50% of the water for urban supply.
The support of industry to full-fledged WRM activities is still scant. We need to evangelise and mobilise the movements of ‘Start Up India’, ‘Digital India’ and ‘Digital Ocean / Digital WRM’. Industry and corporates, within the ambit of their CSR funds, can sponsor policy studies on topics such as drainage levels of groundwater, which can directly benefit communities.
To summarise, underwater Water Resource Management is the domain, which if addressed well, can prove to be a way to miraculous prosperity for a water-rich country like India.