An assessment of the health and socio-economic impacts of the Barekese Dam on human communities downstream

Environmental health and socio-economic impacts on human communities downstream were conducted by a survey research and laboratory investigation about 27 years after the construction of the Barekese Dam. The test communities were Barekurna, Aninkroma and Hiawo Besease, and the control community was Kumi. These are all geographically located in the Atwima District of the Ashanti Region. The field studies were conducted for four months and the laboratory work about two months. Both descriptive and analytical approaches were used in the epidemiological investigation of urinary schistosomiasis, malaria, infectious hepatitis, diarrhoeal diseases and scabies. Matrix analysis of the impacts was conducted under three phases: pre-construction phase/ environmental baseline (in 1966), construction phase (1967-1971) and late operational phase (1997! 98). It was revealed that the environmental quality of all the communities during the pre project phase was desirable. The impacts were +143.7, +142.5, +215.7 and +255.5 impact units for Barekuma, Aninkroma, Hiawo Besease and Kumi, respectively. At the end of the construction phase the environmental quality had deteriorated by -1 85.5%, -180.8% and -432.1% for Barekuma, Aninkroma and Hiawo Besease, respectively. In the late operational phase the environmental quality deteriorated further by -679.9% and -698.9% for Barekuma and Aninkroma, respectively based on the baseline values. However, Hiawo Besease registered -3 97.8% similarly based on the baseline value. This represented a slight improvement of + 10.3% over the construction phase impact. Kumi on the other hand maintained the highest environmental quality throughout all the phases obtaining positive impacts of +96.5 and +89.6 from the construction and operational phases respectively because it did not appear to have been adversely affected by the creation of the dam. The network method also revealed the following expected environmental impacts: Barekuma (-273.92), Aninkroma (-317.05), Hiawo Besease (-1 55.65) and Kumi (-0.05), the most affected community being Aninkroma. EHIA revealed that among the five endemic water-related diseases, urinary schistosomiasis had increased sharply after the completion of the dam at Aninkroma and Barekurna from a prevalence rate of 9.8% (Ariinkroma) and 21.6% (Barekuma) in 1971 to 40% and 44.5% respectively, increase was from 19.5% in 1971 to 26.2% in 1997. Similarly the increase from 0% to 1.1 % at Kumi was insignificant (P<0.01). Generally, there had not been a significant increase in malaria and scabies in all the communities after the completion of the dam. Infectious hepatitis has rather significantly decreased at Barekuma from 11.4% in 197 Ito 6.8% in 1997 (P>0. 05) whereas in the other communities the differences are not significant. With respect to diarrhoeal diseases there has been a significant increase at Kumi from 1.8% in 1971 to 16.1% in 1997 (P>0.05) but the difference in each other community was insignificant (P<0.05). The operational impacts have adversely affected the downstream water quality: Barekuma, Aninkroma and Hiawo Besease registered - 204.2, - 184.8 and -213 impacts, respectively. Generally the socio-economic status in the test communities has probably been adversely affected as has been revealed by the network method. The results for this study are discussed and mitigative measured have been developed although no cost-benefit analysis was undertaken.

Source: KNUST