Rainwater Harvesting in Uganda 2009

This project was adopted by Duke-EWB in January of 2006. Central Buganda University (CBU), a small rural Ugandan university, requested help from EWB to help find a more abundant and reliable water source for the University and the two neighboring villages (Kasaka and Kanoni).

PROJECT LEADERS

Current: Matt Ball (matthew.ball@duke.edu) and Patrick Ye (patrick.ye@duke.edu2007-2008: Kerry Costello BME/ME ‘08 (kec13@duke.edu), Zoë Englander BME ’08 (zae2@duke.edu2006-2007: Yaqing Wen BME ’07

PROJECT SUMMARY

This project was adopted by Duke-EWB in January of 2006. Central Buganda University (CBU), a small rural Ugandan university, requested help from EWB to help find a more abundant and reliable water source for the University and the two neighboring villages (Kasaka and Kanoni). Uganda has two wet and two dry seasons during the year, and although CBU has plenty of water during the wet seasons, there is a shortage toward the end of the dry seasons. An initial site assessment was made during May of 2006. The results of the site assessment showed rainwater harvesting with a related health education program would be the best method to increase the water supply and improve health in the area [for more information, see “Site Assessment” below]. Back at Duke, EWB students spent the next school year researching and designing a rainwater harvesting system which was implemented at CBU in the late summer of 2007 [for more information see “Implementation” below]. For future work on this project, see “Future Plans” below, or contact one of the project leaders.

SITE ASSESSMENT

Engineering

The CBU site assessment was conducted from May 15th-30th, 2006 by the following team of Duke students and faculty:

  • Benjamin Schaefer Abram (CEE ’07)
  • Kerry Costello (BME/ME ’08)
  • Lee Pearson (CEE/BME ’08)
  • Yaqing Wen (BME ’07), and
  • Yvonne Yamanaka (BME ’08)
  • CEE professor Dr. Henri Gavin
  • CEE professor Dr. Andrew Schuler.

The team looked at availability of water in the region and the different sources of water, conducted a watershed analysis of the area, conducted a stress test on a borehole to determine the properties of the aquifer, and tested water quality (E. Coli and total coliform contamination, amount of chlorine necessary to sterilize the water from each source, and arsenic and nitrate levels) in the three main sources: boreholes/wells, springs/streams, and rainwater harvesting tanks. Although all sources had safe levels of arsenic and nitrates, springs were highly contaminated with E. Coli. The aquifer was overstressed, so additional boreholes would not add to the amount of water available to the community. Therefore, rainwater harvesting was determined to be the best option to increase the water supply. Household water set aside for drinking was also tested and found to occasionally have more contamination than the sources it was originally taken from.

Community Health

As a result of this surprising finding, a related health education program emphasizing “point of use” water purification was devised. Many of the health and sanitation education posters in the area had been donated by international aid organizations and thus were written in English, rather than the local language, Luganda. During the site assessment, local doctors translated these posters into Luganda. EWB used these translations to produce new posters, which were brought back to the community during the implementation trip.

IMPLEMENTATION

The Implementation trip took place from July 23rd-August 20th, 2007 and team members included:

  • Matthew Ball (’10)
  • Kerry Costello (BME/ME ’08)
  • Liza Crabtree (CE ’08)
  • Zoë Englander (BME ’08)
  • Philip Wolfe (ME ’08)
  • Patrick Ye (’10)
  • CEE professor and EWB faculty advisor, Dr. David Schaad.

Engineering

The team constructed an 11,000-liter rebar reinforced octagonal concrete tank behind Henry Hall on the CBU campus. The local style of gutters (square U-shaped) were attached to two thirds of the back of the building and one third of the front and connected by an “aqueduct” (extra gutters held up by wooden posted concreted into the ground). The first-flush system was a new component of the design that EWB was the first to bring to the area. This system, made from simple PVC tubing, diverts the first wash of water that comes off the roof away from the tank in order to keep out dust, leaves, bird feces, and other debris that has settled on the roof between rains out of the main tank. The tank has four “entry/exit” points. There is a spigot on the bottom of the tank for the community to use to fill up jerry cans of water. This spigot comes out in a concrete trench with concrete stairs leading down for easy access. The trench allows for excess water to be diverted away from the tank, ensuring the immediate tank area will not be eroded by runoff water. There is also an overflow pipe at the top of tank, which is open to the air but covered with mesh to keep out insects and debris. This overflow pipe runs down to a sand and gravel filled pit which helps the excess water be absorbed by the ground without causing too much erosion. There are also two access areas for cleaning the tank. One is a washout pipe at the bottom of the tank that allows the entire tank to be emptied if the water has been contaminated (it flows to the same gravel pit as the overflow pipe). Atop the tank is a hatch, which allows a person to climb inside for cleaning/maintenance as necessary. This hatch is locked when not in use.

Community Health

The health component of the trip included the first flush system mentioned above, hanging up posters written in Luganda with health and sanitation related messages at local clinics, schools, and water sources, and giving out shoes donated by the Pratt and Duke community. After water related illnesses, worms are one of the most prevalent health issues in the area, especially with children. By giving out shoes to children who did not already own them, in addition to giving their schools the health education materials we brought, we hoped to help educate the children about what causes the illness and thus lower the incidence of worms in this community.

FUTURE PLANS

There is a possibility of future trips to construct more rainwater harvesting systems and/or repair current systems. The CBU church and the administration building were identified as ideal locations to set up systems. On the summer 2007 implementation trip, gutters were only put up on half of Henry Hall. These gutters could be completed on a follow-up trip. Some of the current systems, such as those at the primary school, have fallen into disrepair due to lack of funds. These systems could be repaired and updated with first flush systems and new hardware. Another possible partner is the Homeland Orphanage in Kasaka, where many of the donated shoes were given out, on multiple school and curriculum development projects. Dr. Gavin has been working to find funding for this project. We have also been looking into the possibility of turning either or both of these projects into DukeEngage opportunities.