February 22, 2024, Thursday
Nepal 1:37:26 pm

Rainwater harvesting a viable solution for climate action

Nepal needs strong actions, irrigation and environment conservation

The Nepal Weekly
January 30, 2024

It is known to all that 71 percent of the Earth is covered by water, 96.5 percent of which is covered by oceans, and only 2.5 percent of fresh water is used for human needs. So, we have only a limited amount of fresh water on the earth.

Most of the Earth’s water is saltwater, which is unsuitable for human consumption or agriculture. Of the remaining freshwater, much of it is locked up in glaciers and polar ice caps, leaving a relatively small amount available for human use. Conserving and protecting this limited resource is essential to ensure its availability for future generations. But climate change is also likely to affect this limited supply of water.

Climate change is likely to result in changes in precipitation patterns, with some areas experiencing increased rainfall while others experience drought. This can lead to changes in freshwater availability, with some areas having more water than they need while others suffer from water scarcity. And Rising temperatures can cause more evaporation from rivers, lakes, and other freshwater sources. This can lead to reduced water levels and increased salinity, making using the water for human consumption or irrigation more challenging. In addition, climate change is causing glaciers and snowpacks to melt at an accelerated rate, which can lead to flooding in the short term and reduced water availability in the long term. Many regions depend on glaciers and snowpacks as a primary source of freshwater. Also, Climate change can impact water quality. For example, increased temperatures can increase harmful algal blooms, contaminating freshwater sources and making them unsafe for human consumption.

Overall, climate change is likely to impact freshwater resources significantly, and it is essential to mitigate its effects and ensure that everyone has access to safe and clean water. Therefore, freshwater conservation is being done through various methods worldwide. One of the most effective practices in that regard is rainwater harvesting.

Rainwater harvesting is collecting and storing rainwater that runs off from rooftops, parks, open grounds, etc. This water runoff can be either stored or recharged into the groundwater. More read.

Rainwater harvesting helps conserve freshwater resources by reducing reliance on groundwater and surface water sources. Collecting and using rainwater can lower the water we take from these sources, which can help preserve them for future generations. It can significantly reduce our water bills by providing a water source for non-potable uses such as irrigation, flushing toilets, and washing clothes. This can lead to significant cost savings over time. Also, it can help to manage stormwater by reducing runoff and preventing flooding. By capturing rainwater on-site, we can reduce the amount of water that flows into storm drains and reduce the risk of flooding. Rainwater is generally free from chemicals and contaminants found in tap water. By using rainwater for non-potable purposes, we can reduce our exposure to these chemicals and improve the overall quality of the water in our environment. Rainwater harvesting is a sustainable practice that promotes environmental stewardship and reduces our impact on the planet. By conserving water and reducing our reliance on traditional water sources, we can create a more sustainable future for ourselves and future generations.

RWHas an effective solution for climate change adaptation

Rainwater harvesting is an effective solution for climate change adaptation because it helps mitigate the impacts of droughts, floods, and other extreme weather events that are becoming increasingly common due to climate change. Climate change is expected to lead to water scarcity in many regions, making conserving and managing water resources efficiently essential. Rainwater harvesting can increase water availability for various purposes, including irrigation, drinking, and domestic use. Also, harvesting rainwater can help communities become more resilient to droughts by providing them with a reliable water source during dry periods. Unfortunately, climate change is also causing more frequent and severe flooding in some areas.

Harvesting rainwater can help reduce the amount of water that runs off into rivers and other water bodies during heavy rainfall events, thereby reducing the risk of flooding. With the increase in the global population, municipal water supplies are becoming strained, and water demand is expected to increase in the coming years. Harvesting rainwater can help reduce the need for municipal water supplies, reducing the strain on these resources. Many rely on water transported over long distances, leading to high energy consumption and carbon emissions. Harvesting rainwater locally can help reduce the carbon footprint associated with water transportation. So rainwater harvesting is an effective solution for climate change adaptation because it increases water availability, reduces flooding, decreases demand on municipal water supplies, increases resilience, and lowers the carbon footprint associated with water transportation. 

Climate change impacts in Nepal, like around the globe, primarily manifest through water; with changes in the precipitation pattern altering the availability of water. Impacts can be delayed onset of the rainy season or even extended periods of drought or the period between successive rain events that can create water stress and competition between different uses. High seasonal fluctuation of rainfall and river flow; spatial and temporal water scarcity and the increasing incidences of droughts brought about by climate change suggest that water harvesting is a viable strategy to enhance resilience and adaptation to climate change. Simple storage tanks or reservoirs in a suitable location can be formed with dams to capture water and store it for subsequent use. In Nepal, the wet monsoon season – with four months of heavy rain and eight months of sparse rains – dictates that water be stored in rivers for irrigated agriculture as well as hydropower production. Climatic conditions do not require the storage to be extended beyond the year and thus are relatively smaller in size, in comparison to multi-year storage dams required in other countries around the world.

The government’s policies also direct people towards adopting water storage, inter-basin transfers, conservation ponds, water collection ponds, water recharge systems, and water reservoirs to augment water and food and energy securities at multiple scales. These policies need to be made more action oriented backing up by suitable budgetary outlays with programs and projects. Capacity building at all levels, federal, provincial and local governments should be carried out in tandem with professional inputs in identifying locations, designs, specifications and prototype developments.

The technology adopted in the households, few offices, Kathmandu Metropolitan City, Chure Conservation Programme are exemplary in Nepal’s context. These all needs to be widely adopted in the country’s mountains and hills including the Chure region. Rainwater harvest in Chure can contribute to conservation of Chure ecology and also the plains down to it. Likewise, in the hills, this technology can contribute to irrigate arable lands to increase production of food materials.