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4.4 Plantation Farming on River Banks
Large tract of land has been cleared for rubber plantation farming close to the river banks. There are also a few tracts of cocoa and oil palm plantations in the same area. These farming
activities are extensively influenced by companies like GREL and Norpalm who provide credit facilities to out-growers. This partly accounts for the rapid growth of croplands and
grassland observed under the land cover analysis. Until the rubber trees are matured, the effect on the ecosystem is quite high as previous virgin forest will be lost till seven years
when the rubber would mature.
See changes in the ecosystem of the Ankobra caused by farming and other human activities between 2012 and 2015 in appendix 4.
Plate 13 Land Cleared for Rubber Plantation
4.5 Mining Activities on the Ankobra River
The entire Ankobra Basin contains deposits of all the minerals produced and exported from Ghana. Hence, much investment has gone into mining prospecting and mineral exploitation
with a steady increase in the operations at the expense of an accelerated rate of deforestation and pollution. The largest mining concessions are located mostly in the mid-eastern portions
of the basin mainly in Tarkwa, Nsuta and Bogoso. The mining activities with profound effect on the ecosystem within the Ankobra estuarine can be categorized into two groupings which
include heavy industrial mining as practiced by the companies upstream in Tarkwa, Bogoso, Prestea, Nsuta and Awaso. The second group include small scale mining which are conducted
by private companies and individuals either legally or illegally. Activities of these mining companies are hardly regulated and supervised. According to the WRC all these companies
dump untreated mining affluent directly into the Ankobra
5
Undoubtedly, the aquatic ecosystems of the Ankobra Basin are under a significant pressure due to the poor surface water quality as a result of mining activities, poor solid waste
infrastructure and lack of environmental awareness. Therefore, in defining the minimum amount of flow required to maintain the aquatic ecosystems of the basin, a certain acceptable
water quality level for the sustenance of these ecosystems must be specified and maintained.
5
Water Resources Commission 2009, Ankobra – Integrated Water Resource Management IWRM Plan, Final
Report
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Furthermore, the flow of the Ankobra River and its tributaries particularly during the dry season has a significant impact on the flora and fauna associated with the prevailing aquatic
system. Water quality decline and Water pollution have been identified as the leading water management problems in the basin. This is due mainly to disposal of untreated mining
effluents from locations such as Tarkwa, Beposo, Prestea, Nsuta and Awaso.
According to a study conducted by the Water Resource Commission WRC “the largest source of arsenic seems to be along the Ankobra River from Prestea downstream to
Dominase”. Dominase is the largest commercial center in the SMFP Ankobra project area and the river flows downstream directly through the identified areas into the sea at Sawoma.
4.6 Poor Quality of Water