Rainwater harvesting/Rwambu, Uganda - Clearwater Revival
Project period: Implementation runs October 2012 up to December 2013. Documentation and learning will take a longer time, possibly until the end of 2014. A plan for research and documentation via satellite imagery is currently being developed together with MetaMeta.
Several hillsides in the area of different soils and inclination have all seen an increase in agricultural activity, but a dropping water table. Even though this area receives ample rainfall, 700 to 1000 mm, the water table dropped considerably the past years and springs and shallow wells have dried up, possibly due to the rapid increase in agricultural activity and the decrease of forest and wetland. Local people have seen in recent years that rainfall has become more erratic, indicating the effects of climate change.
Socioeconomic and cultural conditionsEdit
A feasibility study carried out in 2011, indicated that 75% of the people in the area live on less than one euro per day. The staple food is plantain which grows in abundance in the area but is under threat of bacterial wilt. Cash crops are on the increase, like coffee, groundnuts and cabbage. There was a high migration of people from the south, near the Rwandan border, bringing in different ethnic groups. Islamic and Christian faiths are followed in the region.
Grassy hills up to 1550 meters and valleys at about 1250 meters above sea-level make up the region. Other hills may have rocky surfaces. The slopes of the hills consist of loamy and clay soils, reaching to a layer thickness of 4 meters. In the valleys, a wetland or marshland follows the Rwambu river.
The uphill areas have been facing a dropping water table, which lead to the depletion of water sources. Shallow wells and springs had to be abandoned and people had to walk further down the hill to fetch water from water sources in or near the wetland. This is not a desirable situation, since time spent on fetching water has increased and the ecosystem of the wetland has been decreasing. In the area there has been some accidental success in reviving springs by diverting and capturing runoff when a small elevated dirt road was built. Building upon this example, a variety of techniques to recharge the groundwater table and revive the springs will be tested in this project.
Location and partnersEdit
- Location: The Rwambu area is in the West of Uganda on the boundary of the Ibanda and Kamwenge districts. Latitude: 0° 1'33.03" North of the Equator. Longitude: 30°24'55.54" East of Greenwich Meridian.
- Main partner: Joint Effort to Save the Environment (JESE)
- Role and responsibility of main partner: JESE proposed the intervention area, worked with RAIN and Wetlands International and URWA on the program development and is the sole implementer of the project.
- Role and responsibilities of other partners: Technical advice, program advice, and capacity building.
The recharge will act to stabilize the groundwater table and hopefully the groundwater will be released slowly through the revival of springs. Part of this program is to compensate people who had to abandon cultivation in the wetland area. Water is to be used for drinking but also for yam production and irrigation.
This pilot consists of several technologies to restore the water level to guarantee revival of dried springs and wells. Four different methods are tested, all adapted to the different context of the spring or well.
A dried spring is in a valley where, during the rains, water flows in a small stream. Uphill of this spring a cascade of permeable blockages will be constructed with gabions to block the flow of the runoff and allow it to infiltrate.
- Uphill from another dried spring where there is not such a clear valley, two infiltration pits are dug through a thick layer of clay soil to reach the subsoil. Runoff from the slope is guided into these pits to recharge the groundwater.
- Uphill from a dried shallow borehole we combine terracing (FanyaJuu), road runoff infiltration pits, and ponds to restore the water level around the borehole.
- Finally, a shallow well will be constructed and combined with recharge measures close to the well in a grazing area. Since this is pasture land, two small earth bunds with a flatter surface and gentle slopes will replace the the usual terraces. This will allow grazing of animals to continue, but still provide infiltration of surface runoff close to the spring. The spring will be turned into a shallow well for multiple use, such as for cattle.
- Revival of springs to provide clean water for people, cattle and agriculture. Documentation of the impacts of the technologies applied will provide success stories and lessons learned for further upscaling.
- Pilot a variety of recharge technologies for this specific environment.
- Valley 1K2 Rwesegere spring improvement, create 3 semi-permeable check dams upstream.
- 2 places with percolation pits to improve recharge: percolation pits and ponds. Promote pits and trenches for the farmers.
- Establish 2 small rock catchments with 2 ferrocement tanks of 30 cubics.
- 1K4 Kinagamukono spring protection: 2 small earth bunds, replant the grass, animal friendly walls, flatter surface and gentle slopes.
- Rwensigire trading center borehole: increase recharge on the uphill of the borehole, look at the potential for infiltration pits/ponds. Improve agricultural land (with fanya juus). Desilt pump after recharge.
- Kichwaba spring improvement: construct storage tanks to tap water from the spring and supply to neighbouring communities.
- Capacity building in 3Rs for the community and district local government officials.
Here is a SWOT analysis (Strengths, Weaknesses, Opportunities, and Threats) of the project:
|Current situation||Expected results||Actual results|
|Water supply||Dried up springs and shallow wells, people are now depending on open source of water such as the wetland.||Several springs revived, improvement of soil and water retention for 150000 M2 agricultural land.|
|MUS||Drinking water plus sufficient water for increased agricultural production on small irrigated plots.||Better soil moisture for agricultural land|
|3R||Recharge||Recharge of water table uphill and slower drainage into wetland|
|Business development||Yam production near the sources, which will increase income||Environmental sustainability of these plantations|
- Type(s) of water harvesting: in situ
- Type(s) of storage system(s): terraces, woodlots, stone and grass bunds
- Number of systems: 6 different systems
- Original Akvopedia.org article and more images: akvopedia.org/wiki/Rwambu,_Uganda_-_Clearwater_Revival