KATHMANDU — Until the summer of 2024, residents of Rajabahs village in Nepal’s southeastern Madhesh province reeled under a water shortage for more than eight years as wells and springs dried up amid extreme summer heat.

“We didn’t even have enough to drink, let alone bathe or wash clothes or irrigate our fields,” farmer Kul Bahadur Adhikari remembered. “We were looking for a solution when we realized that if we could collect water from a spring which provides water during the wet season, in a pond, we can use it in the dry season,” he told Mongabay.

As Nepal’s plains face severe drought, communities such as the residents of Rajabahs and the government are increasingly turning to artificial ponds as a nature-based solution for water scarcity amid experts warning that unscientific construction and poor governance could limit their long-term effectiveness.

When it rained in the summer of 2024, the village of Rajabahs, with around 83 households, collected water in a government-funded $15,000 pond covering an area of 4,740 square meters (51,030 square feet). The following dry season, they could not only draw water from the pond to irrigate their corn and paddy fields, but each household could also draw around 70 liters (18.5 gallons) of drinking water from their hand pump every day.

“We didn’t feel any scarcity of water even as the whole of Madhesh province was impacted by a drought this year,” said Shiva Kumar Rana, a member of the Markaura Community Forest in Rajabahs, Mahottari.

The “slow burn” drought Rana was referring to has been particularly severe this year. Due to the delayed start of monsoon rains in the region, farmers couldn’t plant their staple paddy on time. This led Nepal’s federal government to declare Madhesh as a drought-affected disaster zone. According to the Department of Agriculture, as of July 25, paddy had been planted on only 51% of the 580,000 hectares (1.4 million acres) of land in Madhesh province.

A rapid assessment report by the International Centre for Integrated Mountain Development describes the situation as a combination of meteorological drought (less rainfall than normal) and a hydrological drought (drying of rivers, lakes and groundwater). Together, these have led to an agricultural drought, where crops don’t get enough water, leading to poor harvests and economic stress for farmers.

The Observed Climate Trend Analysis of Nepal report by the Department of Hydrology and Meteorology signals the findings of the assessment could be relevant in the long term as well. The report indicates a trend of increasing temperature and a decline in average annual rainfall in Nepal’s Madhesh. According to the report, over the past 40 years, the average temperature has increased by 1.4° Celsius (2.5° Fahrenheit) in Madhesh region and average annual rainfall has declined by 72 millimeters (2.8 inches).

Anecdotal evidence also backs the findings. Kaustuv Raj Neupane, a Ph.D. student in watershed management at New Mexico State University, U.S., who researches recharge options for water management, said, “It has been a long time since we had a normal monsoon season. Thirty years ago, it used to rain for a week or two, which helped replenish the water.

“Now, there is a heavy downpour for a short period, and all the water runs off quickly into the ocean.”

The water retention service that the ponds are providing villages such as Rajabahs was traditionally provided by the Chure Range north of Madhesh. This “fragile” range, formed by river deposits, plays a crucial role in groundwater retention and recharge in the Indo-Gangetic Plains. Previously, the Chure’s tree cover allowed water to percolate into the soil, recharging the water table. Now, with massive deforestation, high-intensity rainfall causes flash floods and soil erosion without replenishing groundwater.

Nature-based solution

The story of Rajabahs echoes the growing popularity of artificial ponds in Nepal’s plains as a nature-based response to adapting to drought and decline in groundwater table.

Several local communities Mongabay talked to said they found that ponds were effective in addressing and reducing water shortages. Ghorahi sub-metropolitan city in Dang in western Nepal, for example, has constructed 45 ponds over the past five years. “We are reaping multiple benefits from artificial ponds,” said Narulal Chaudhari, the town’s mayor. “By spending around $500-$150,000 on a single pond, we have been able to help farmers not just with agriculture, but also pisciculture,” he said, adding that the ponds have helped regenerate springs as well.

The success of some of the ponds have also been documented scientifically. A hydrogeological assessment of groundwater resources in the Khutti Khola Watershed, Siraha district in eastern Nepal, suggested that artificial ponds can be a sustainable solution to mitigate water scarcity. It also noted that ponds help improve the livelihoods and resilience of local communities. Another study found that when an artificial pond was built in the Ratu Khola Watershed, groundwater levels rose by 1.5-3 m (4.9-9.8 ft) during the dry season.

Some community forest user groups said ponds inside their forests have not only helped recharge groundwater, but also address negative human-wildlife interactions. The Ratu Mahila Community Forest Users Group in Bardibas-3 constructed a pond in their community forest. Kedar Bhandari, a resident of Kalapani village in Bardibas-3, said that after building the pond, human-wildlife conflict decreased. “In summer, wildlife used to come to the village searching for water,” he said. “After the pond was made, they didn’t come to the village as often. We also use the pond’s water to control wildfires during the drought season.”

Recognizing the present and future challenges linked to water scarcity in the region, several NGOs and both the provincial and federal governments have included collecting water in recharge ponds as an adaptation measure to help farmers cope with droughts. While the Madhesh province government has included recharge pond programs in its official budget, the federal government implemented the Building a Resilient Churia Region in Nepal program funded by the Green Climate Fund, with a grant of about $39.4 million to build recharge ponds. Bishnu Hari Poudyal, technical adviser of the program, said recharge pond construction is one of its major components. “Recharge ponds retain rainwater and runoff and recharge the ground. This also helps control soil erosion,” he explained.

Knowledge gap

While communities report that ponds improve groundwater recharge, experts caution that poor design, weak governance and overreliance on ponds could limit their long-term benefits.

Locally dug ponds intended to increase groundwater recharge and provide irrigation have, in many cases, become traps for wildlife. In several parts of the country, monkeys have died after falling into such ponds. For example, on Oct. 2, 2022, 27 monkeys drowned in Sandhikharka, Arghakhanchi. Similar cases have been reported in Gorkha, Okhaldhunga and Sindhupalchok districts.

Ngamindra Dahal, chairperson of the Nepal Water Conservation Foundation, said many of the ponds constructed by local governments are not scientifically designed. “I found some ponds were lined with concrete,” he said.

Ram Prasad Chaudhary, a biodiversity expert and professor emeritus at Tribhuvan University, also shared some cases where the construction of ponds couldn’t be justified. “In Saptari and Sindhuli districts, for instance, ponds were built just 15 m [50 ft] away from river banks,” Chaudhary said, “There is no need for a pond so close to the river — it is simply a misuse of the budget.”

Site selection is an important variable when it comes to deciding the feasibility of ponds, said Neer Shakya, a senior hydrologist and visiting professor at Tri-Chandra Multiple Campus, Kathmandu. “If natural recharge is already sufficient, additional ponds are not necessary,” he noted.

For other experts, building a pond requires consideration for different hydrological and geological factors as well. “Understanding the water budget and the dynamics between surface water and groundwater is essential for identifying recharge areas,” said Neupane, in the U.S. “A watershed is connected horizontally, vertically and laterally, so any recharge strategy, such as pond construction, must consider how it supports recharge based on geology and other geomorphic factors.”

He noted that as recharge occurs widely across aquifers through precipitation and percolation in humid areas of Nepal, spreading water through the passage of stormwater on agricultural or fallow land may be a suitable approach to improve recharge.

As the number of ponds increase in the country, there is also a need to make people aware about what they can and can’t do, researchers argue. In the same vein, Dahal added, “There is a huge gap in understanding. We need to make the concept and its implications to the local people and the governments.”

Neupane emphasized that, along with building artificial ponds, it is important to promote traditional agricultural systems in the Chure and Bhabar zones. “Agriculture supports groundwater recharge; it is a nature-based solution,” he said. “When agriculture is abandoned and land is left barren, it harms the recharge system.”

Banner image:An Indian pond heron (Ardeola grayii) in a pond in Nepal. Image by Mildeep via Wikimedia Commons (CC BY-SA 4.0).

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Citations:

Aryal, Y. M., Poudel, P., Ansari, K., & Paudyal, K. R. (2023). Application of geospatial techniques for artificial recharge to groundwater in Ratu Khola watershed, Central Nepal. Journal of Institute of Science and Technology, 28(1), 1–10. doi:10.3126/jist.v28i1.47459

Department of Hydrology and Meteorology (DHM). (2017). Observed climate trend analysis in the districts and physiographic regions of Nepal (1971–2014). Government of Nepal. https://www.dhm.gov.np/uploads/dhm/climateService/Observed_Climate_Trend_Analysis_Report_2017.pdf

Khadka, G., Dhungana, S., Acharya, M., Sah, R. B., & Paudyal, K. R. (2024). Hydrogeological assessment of groundwater resources in Khutti Khola Watershed, Siraha District, Eastern Nepal. Journal of Nepal Hydrogeological Association, 1(1), 79–93. doi:10.3126/jnha.v1i1.78224

Shrestha, S., Devkota, K., Dahal, N., & Neupane, K. R. (2021). Application of recharge ponds for water management: Explaining from a nature-based solution perspective. In D. Khatri, K. R. Neupane, & K. Devkota (Eds.), Dhulikhel’s journey towards water security: Insights for policy and practice (pp. 142–161). Southasia Institute of Advanced Studies.