Mon | Aug 20, 2018

Basil Fernandez | Water reality may drown Bernard Lodge city plan

Published:Sunday | April 22, 2018 | 12:00 AM
Basil Fernandez
In this May 2016 photo, a rider makes his way along the Bernard Lodge main road, overlooking a section of Highway 2000. A master plan has been developed to transform old sugar lands at Bernard Lodge into a new town.
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I have noted the announcement by the prime minister of the establishment of a city on the Bernard Lodge lands in South St Catherine. I have also noted the three editorials in The Gleaner (the latest, Monday on April 2, 2018) dealing with the need for a more robust debate and possible impacts on the agricultural sector and economic growth for the country.

On the matter of robust debate, I wish to discuss not just the impact on agriculture, but the impact on water resources, a critical element in agricultural production, economic growth and sustainable development.

The proposed Bernard Lodge City (BLC) is located atop the alluvial formation (sand and gravel) of the Lower Rio Cobre Hydrologic Sub-basin in south St Catherine. The top 33 metres of the alluvial formation functions as an aquifer, with more than 80 wells tapping the coarse sands and gravel horizons below ground.

In the Bernard Lodge area, there are more than 53 wells tapping the alluvium aquifer. The wells at Bernard Lodge have provided water for irrigation of sugar cane and other crops, as well as water for industrial and domestic uses. The wells drilled in 1986 for the Agro 21 project are now owned and operated by the National Irrigation Commission (NIC) and provide water for irrigation, while the National Water Commission's (NWC) wells provide domestic water to Portmore and Greater Spanish Town.

The NWC wells were upgraded under the KMA Water Supply Project funded by a loan of reportedly US$63m from the Japanese Bank for International Cooperation (JABIC), now usurped under the Japanese International Cooperation Agency (JICA). The Government of Jamaica provided counterpart funding for the project.

 

Inefficient irrigation

 

The use of the alluvium formation as a source of groundwater resulted from the inefficient irrigation of sugar cane in the Bernard Lodge area using surface water from the Rio Cobre Irrigation System (gravity flow from the dam across the Rio Cobre River at Crescent). This led to an increase in the groundwater table and storage within the alluvium formation. The wells were primarily developed by the Bernard Lodge Sugar Estate and the Caymanas Sugar Estate, and at that time, there was no licence allocating the volume of water to be abstracted from each well, which has led to overpumping of the aquifer.

The decline in sugar cane production and the closure of the Agro 21 project in the Bernard Lodge area in the 1990s reduced the irrigation recharge to the alluvium aquifer, leading to a decline in water table and the reliable yield of the aquifer. The decline in water levels in the Bernard Lodge area is averaging three metres because of reduced recharge and abstraction exceeding recharge and the construction of an unpaved drain between Caribbean Estate and Portmore that drains water from the aquifer.

The Water Resources Authority (WRA), after the completion of the KMA Water Supply Project, recommended and got approval from Cabinet for an aquifer protection zone to be declared over the aquifer to protect water resources and prevent any further construction of housing atop the alluvium aquifer.

The land-use changes prior to this declaration within the Lower Rio Cobre Sub-basin atop the aquifer protection zone and the alluvium aquifer include the construction of houses at Caribbean Estate, Morris Meadows and Dunbeholding, with large-scale squatting at Clifton on lands belonging to Sugar Company Holdings Jamaica (SCJH). Total area was over two square kilometres.

In March 2016, there were five applications seeking approval from the WRA for housing development atop the aquifer protection zone (alluvium aquifer). These were held in abeyance pending an assessment of the cumulative impact of these proposed developments on water resources of the alluvium aquifer.

The total new area to be developed would be approximately 8.5 square kilometres and would require additional water of more than 10,000 cubic metres per day, or 2.2 million imperial gallons per day, for meeting the domestic demand. This could not be supported as the aquifer reliable yield and groundwater storage (water table) had declined significantly.

 

Demand cannot be met

 

The BLC is proposing 17,000 houses with light industrial and other construction. The water demand calculation for 17,000 houses indicates approximately 15,000 cubic metres per day, or 3.22 million imperial gallons per day. This does not include the water demand for the industrial and other amenities. This water demand cannot be met, neither from the alluvium aquifer nor the limestone aquifer of the Lower Rio Cobre Sub-basin, the water resources of which are both over allocated.

It is possible that the NWC and NIC could lose the wells now in operation. If this water is taken from the Rio Cobre, it would significantly impact the farmers (including aquaculture), which would see a further decline in agriculture, the operations of the NIC and economic growth.

The country has lost rich agricultural land (no salinisation of soils) with irrigation at Vineyards, Bushy Park, (where some of the best onions I have seen were produced) and Whim, Old Harbour, to housing with the irrigation wells being converted to domestic use.

At BLC, it is possible that the irrigation wells now in production and supplying water to farmers could be converted to domestic uses (as was done at Vineyards and Whim), but this would lead to increased abstraction as while irrigation wells are rested during the rainy seasons, domestic wells are run 24/7. In addition, domestic use is 100 per cent consumptive, and there would be no water from the BLC being discharged to recharge the aquifer.

The Bernard Lodge City would, therefore, lead to increased water demand, a decline in groundwater levels and storage, and the potential for seawater intrusion into the aquifer. There may be other options to maintaining the agricultural water supply, such as use of treated effluent from the Soapberry sewage plant, but this would require significant funding to improve the effluent quality to make it safe for agricultural use and recharging the aquifer.

There is clearly a need for a more robust debate on Bernard Lodge City as set out in The Gleaner's three editorials to date.

- Basil Fernandez is former managing director of the Water Resources Authority. Email feedback to columns@gleanerjm.com and bpfernandez1@gmail.com.