The selection of the Ankobra Basin as the third basin, after the Densu and White Volta Basins respectively, for the implementation of Integrated Water Resources Management (IWRM) by the Water Resources Commission, is a response to current and rising public concern on the impact of mining activities on community livelihoods, human health, water quality and availability, and socio-economic development.
IWRM is a systematic process for the sustainable development, allocation and monitoring of water resource use in the context of social, economic and environmental objectives. This is based on the understanding that water resources are an integral component of the ecosystem, a natural resource, and a social and economic good.
The Ankobra Basin
The Ankobra Basin is one of the south-western basins of Ghana. It is located within latitudes 4o 52'N and 6o 27'N, and longitudes 1o 42'W and 2o 33'W. It is bounded to the East; West and South by the Pra Basin, Tano Basin and the Gulf of Guinea respectively. The basin has an area of 8,403 km2 spanning 11 districts in three regions with Wassa Amenfi, Wassa West and Nzema East Districts making 81% of the total area.
The basin falls under the South-Western Equatorial and the Wet Semi-Equatorial climatic regions. The South-Western Equatorial is the wettest climatic region in Ghana with mean annual rainfall above 1900mm. The vegetation of the basin comprises the Rain forest as well as the Moist-semi deciduous forest.
Water Use in the Basin
Apart from Tarkwa and Bonsaso all other major towns in the basin, notably Bogoso, Aboso, Prestea, Huni Valley and almost all rural communities, rely solely on groundwater as their source of drinking water. The preference of groundwater to surface water as a source of drinking water could be based on the assumption that groundwater would be less susceptible to pollution. This is true to an extent.
However, groundwater in hard-rock aquifers, particularly in mining areas, is known to be vulnerable to quality problems that may have serious impact on human health. The rocks in these areas are often carbonate-deficient and give rise to poorly buffered water. Secondly, in gold and base metal mining areas, sulphides oxidation resulting from chemical and biogeochemical processes leads to the production of low pH ground-water that encourages the dissolution of trace metals into the groundwater system in very high concentrations. The groundwater, thus, becomes dangerous for human consumption.
Apart from domestic consumption, the water resource within the basin is used for irrigation in large commercial farms such as the Benso Oil Palm Plantation, Norpalm Oil Palm Plantation and the Ghana Rubber Estates Ltd. Furthermore, the mining companies also abstract water for processing of ore and as well as dust suppression. A recent report submitted to the Water Resources Commission by the Water Research Institute on Groundwater Inventory and Hydrogeological Assessment on the Ankobra River Basin indicated that there were over 292 boreholes drilled in the basin.
The Ankobra Basin is arguably the most exploited basin in Ghana in terms of natural resources. The major minerals mined in the basin include gold, manganese, bauxite and diamond. The main challenges facing the Ankobra Basin include:
Illegal mining activities (popularly known as Galamsey)
Pollution from indiscriminate discharge of untreated mine effluents
Indiscriminate use of chemicals especially DDT for fishing
Illegal chain-saw operators
Clearing of forest for mining
Poor sanitation in almost all the towns in the basin
Erosion due to the removal of the vegetative cover for mining purposes
Conflicts between Communities, NGOs' and Mining Companies
High sediment loads in water bodies
Towards the setting up of the framework of establishing a basin office to implement the principles of IWRM process in the Ankobra Basin, the Water Resources Commission held a consultative stakeholder workshop in June 2007 to brainstorm the way forward. Consequently, a Basin Officer was recruited and office accommodation has been acquired and rehabilitated. A Basin Board, which was proposed in the consultative stakeholder workshop, to manage and coordinate the sustainable utilization of the water resources in the basin has been setup. The Ankobra Basin Plan has been developed through consultative meetings using the Strategic Environmental Assessment Tools.
The Secretariat has been implementing and monitoring compliance of existing regulations i.e. water use regulations (LI 1692) and drilling license and groundwater development regulations (LI 1827) by undertaking regular and continuous inspection of water abstraction points and processing applications.
The Secretariat has already initiated moves to identify and get small scale water users registered by sending out letters advising water users to regularize their water use. There has been positive response from companies who have drilled their own boreholes.
Some of the major water users in the basin includes but not limited to:
- GoldFields (GH) Ltd, Tarkwa Mine, Tarkwa
- Abosso GoldFields Ltd, Damang
- AngloGold Ashanti, Iduapriem Mine, Iduapriem
- Golden Star (Wassa) Ltd, Akyempim
- Golden Star (Bogoso/Prestea), Bogoso
- Ghana Manganese Company Ltd, Nsuta
- Central Ashanti Gold (GH) Ltd, Bibiani
- Prestea Sankofa Gold Ltd, Prestea
- Adamus Resources Ltd, Nkroful
- Ghana Bauxite Company Ltd, Awaso
- Central Ashanti Gold Ltd, Ayamfuri
- Agro Companies
- Benso Oil Palm Plantation, Benso
- Ghana Rubber Estates Ltd, Agona
- Norpalm Plantation (Yet to be permitted)
The Secretariat has also undertook public awareness programmes such as Panel Discussions on local FM Radio Stations, organization of quiz and essay competitions for Senior High Schools and Junior High Schools respectively.
The Ankobra Basin Secretariat has also been involved in dispute resolutions between communities and mining companies regarding alleged pollution of water bodies and flooding of farms and communities. Among such disputes includes:
Complaints of flooding at Benso
Complaints of flooding at Abekrosi
Complaints of pollution at Adisakrom
Water Resources Commission
Ankobra Basin Office
P. O. Box TK475
Tel: +233 31 209 2815/31 209 2431
Loc: SHC Estate , Tarkwa-Abbosso Road