The UN set as its Millennium Development Goal 7: halving the proportion of people without sustainable access to safe drinking water and basic sanitation.  UNCED and UN-Water have also set their theme forWorld Water Day 2010 (22 March): 'Communicating Water Quality Challenges and Opportunities'.

The Australian Water Association (AWA) is responding to this challenge. From 8-10 March, 2010 AWA will holdOzwater '10, a national water conference featuring "Achieving Water Security" as the headline theme. A free trade exhibition will also be hosted for over 200 Australian and international exhibitors and water industry professionals, and a workshop on the Water Utility Partnerships program will be co-hosted by the Asian Development Bank and AWA.
...and below, an AWA WASH Network member and Water and Sanitation Specialist from Winkfield Pty Ltd, Neil Kerby, shares a story on designing a reliable water supply for the people of Kiritmati Island, Republic of Kiribati. 
A Case Study in improved water supply
New fiberglass elevated tank at London village, Neil Kerby, 2000
Kiritimati (Christmas) Island in the Republic of Kiribati, is the world's biggest coral atoll, is 1.5 metres above sea level, and - only in an El Nino year - enjoys rainfall of about 3 metres. This abundance of 'water' - once every four years - was discovered by both United States and British presences in-country and a water supply system to service their militaries was set-up.

Large "lenses" of fresh groundwater were discovered and galleries were constructed.  These were established in roofed shallow trenches that were pumped to elevated tanks and piped in asbestos cement pipes to various settlements. Over ensuing years 2,000 i-Kiribati established townships in the remnant infrastructure of London, Tabwakea, Banana, Poland and 'Main Camp'.

This is the story of transitioning the 50-year-old water supply system from military use to one fit for local habitation. Put simply: providing i-Kiribati people with access to safe drinking water.

From 1995, AusAID supported an extensive design process, and a later project to improve the water supply. The design involved interviews with local villagers about the performance of the ageing system, and their attitudes and expectations of the proposed water supply.

New fiberglass elevated tank at London village, Neil Kerby, 2000 (see image on right hand side)

  • The feedback was:
 water tanks were scarce so families often drilled or modified the existing pipes to gain access to any water that passed through. This disrupted the water supply and usually meant those downstream - at the edges of villages - were left without water

 breakdowns were common, and access to the technical or material resources they needed to fix the breakdowns were also scarce

 all building materials were scarce - even palm trees failed to provide strong lumber due to their drought-stressed history of growth

 while any available material was salvaged and used, corrugated sheets that were intended to cover open groundwater galleries, had become materials for housing

 social co-operation was generally based around the head of a family unit, and the existing water supply system did not support this structure

 there was poor or no house plumbing which meant erratic access to water, or lengthy delays or travel to other water supplies and water's edge ablutions. Wind pump at Decca groundwater gallery, Neil Kerby, 2000 (see image on left hand side)


The design of
 the improved water system focused on a number of elements:

 Detailed re-mapping of water lenses, and estimation of yields to sustain the proposed 6,000 inhabitants between the irregular rainfalls - An allowance/ provision was made for 50 litres per head for people in villages with access to shallow wells and 67 litres for London-town residents whose wells were salty (0.5m above sea level)

 Buried shallow 400m long slotted pipe galleries to encourage groundwater to run gently to pits where wind and solar driven pumps to lift it to elevated tanks

 Solar powered chlorination (sodium hypochlorite) at each gallery. Chlorine detention of 24 hours to kill Giardia - a small single cell parasite that could cause diarrhea, vomiting and weight loss

 PVC and high density polyethylene (HDPE) pipe - trunk mains to each village (removing the former asbestos cement pipes) with another elevated fiberglass (day) tank

 Placement of a 500 litre day tank on a 3 metre stand at each dwelling. This tank broke the higher transfer pressure, gave 24 hours to satisfy demand and a day's back-up if the system broke down.

The design approach was subsequently adopted across the Republic of Kiribati and especially in Tarawa, where keeping pace with demand had also led to interference with the pipe system and supply failures to the edges of the networks.

Solar pump at Decca groundwater gallery, Neil Kerby, 2000 (see image on right hand side)

Feedback from i-Kiribati residents has been positive.


In 2007 a senior bureaucrat in Tarawa, Kiribati stated that, "the Kiritimati Island water supply was now the best in the Republic". A site visit to South Tarawa and elsewhere also bears witness to the reliability and use of water by i-Kirbati residents.  They are using the household fibreglass tanks at ground level for daily supply - with the village day tank at each village and a rotating fill sequence to each village's tankstand.

A decade on, this water concept appears to still be working - and making a difference to everyday i-Kiribati lives.

Corroded military tank stand London, Neil Kerby, 1999 (see image on left hand side)




For more information:

More on this resource

  • March 2010
  • Australian Water Association (www.awa.asn.au/)
  • 01.03.2010 11:00 | Contributed by: Neil Kerby, member of AWA WASH Network and Water and Sanitation Specialist, Winkfield Pty Ltd
  • http://www.awa.asn.au/