I read the comments from Dr Alfred Sangster yesterday on the issue of the water supply deficiency for the Kingston and St Andrew areas.

The Water Resources Authority (WRA) has not given an illusion as to the sufficiency of water resources across the island - there is enough water to meet our demands - even in severe dry periods. The issue is the harnessing and the efficiency of transmission/ distribution of the water resources.

The WRA has always said that the systems most affected by below-average rainfall are surface water systems that originate on the volcanic/volcanoclastic rock formations that are classified as aquicludes, i.e., do not have storage that maintains river flows in dry seasons. The rivers that supply the KSA-Hope, Wag Water and Yallahs rivers all originate on the aquicludes of the Blue Mountains and, between wet and dry seasons, there is a high variability of flow with significant decline in the dry season.

Groundwater systems

On the other hand, the groundwater systems across the island continue to perform in keeping with their installed capacities/designs, and the comment attributed to the NWC communications manager that all its 460 systems across the island are being affected cannot include groundwater and surface water systems fed from the limestone aquifers.

The rainfall this year has been affected by the El Nino phenomenon that while removing the hurricane risk from the Caribbean also removes the rainfall. El Nino always lead to dry conditions in the Caribbean and wet conditions in the Pacific - note the number of storms across the Asian Pacific this year and the havoc wreaked on the Philippines.

The Water Resources Authority has evaluated the expansion of existing storage systems and the building of new surface water storage systems and unless new water can be found contiguous to the Mona and Hermitage that can fill the expanded storage we will be building more systems to go dry.

The Mahogany Vale Dam, which has been explored since the 1960s by several local and international consultants, has serious geotechnical problems that have prohibited its construction. However, a number of the previously identified dam sites across the island are now being reviewed, and these include Mahogany Vale.

The wet/dry periods come in cycles. Between 2002 and 2008 the island has been in a wet cycle with very high rainfall, rivers flowing above average and groundwater storage at a high level. We now seem to be entering another dry cycle and this is being exacerbated by the El Nino phenomenon. In 2010, we enter the El Nino plus 1 and if there is no receding of the El Nino then we may be facing well below-average rainfall seasons with serious implications for surface water supply systems.

Reducing the impacts

What actions have and can be taken to reduce the impacts of the below average rainfall?

1. The KMA water supply project which has increased the availability and reliability of water (primarily groundwater and the upgrade of the Spanish Town Treatment Plant) for the Greater Spanish Town and SE St Catherine areas.

2. The implementation very shortly of the Kingston and St Andrew Water and Sanitation Project that will reduce systems losses.

3. A review of existing NWC groundwater systems to improve yield and efficiency of wells.

4. Implementation of a strong public education programme to increase the public's knowledge and understanding of the island's water resources and water supply systems and the need for conservation at all times - not just in the dry season.

5. Upgrade the data collection systems to enable more rapid and reliable data analysis to guide allocation, supply and use optimally.

Unfortunately, there is no immediate project that will bring relief in the very short term; all actions are for the medium to long term.

In the 1940s, there was an article in The Gleaner (reproduced in the historical section a few years ago) that there was more rum in storage at Spanish Town Road than there was water in the Hermitage Dam. I think that this comment shows that the water supply of the KSA has not kept pace with the urban expansion, and trying to catch up, while not impossible, will be difficult and expensive.

I am, etc.,

Basil Fernandez

bfernandez@wra.gov.jm

Water Resources Authority

Hope Gardens

Kingston 7