THE EDITOR, Sir:I HAVE read with interest Mr. Kingsley Thomas' proposal to dam the Rio Cobre. Although this proposition seems to be feasible, I am afraid that the geological formations which exist in the Bog Walk gorge rule out any such water impoundment.
Many years ago I was involved in diamond core drilling all over Jamaica, including several investigations of proposed water reservoirs. The results were all, to the best of my knowledge, negative.
Harkers Hall Geology too porous to hold water (conditions similar to Bog Walk gorge).
Mahogany Vale No data available on the rate of sedimentation - fears that dam would silt-up within 10 years.
Rock River Site rejected?
Hermitage Dam Proposal to increase dam height dam sited on a fault no rock encountered beneath centre dam.
Mount Diablo - Proposed tunnel from Ewarton to Moneague below 700ft.no rock - running sands and lignite not feasible.
Mona Reservoir - 80 to 100 feet of porous sand and gravel beneath reservoir water retained, basically by an artificial layer of chemically treated clay.
These investigations reveal that impounding water reserves may seem straightforward, but retaining the water perhaps may be an insurmountable problem.
I am, etc.,
GEORGE P. LECHLER,
P.E
PO Box 147
Kingston 10
