Effects of Oil Production on Groundwater Levels in Lokichar Basin, Turkana County, Kenya

Increased groundwater abstraction may lead to decline in water levels. This study investigated the effects of oil production on groundwater levels in Lokichar basin in Turkana County, Kenya. The specific objectives were to: 1) establish changes in groundwater demand and 2) determine borehole water levels in the study area. Water levels for two boreholes within the study area were recorded between 12th August and 11th September 2020. The Kenya Ministry of Water and Irrigation Design Manual guidelines were adopted in estimating the groundwater demand in the study area. The study showed that groundwater demand in Lokichar basin increased from 1,846,001.55 l/d in 2009 to 4,951,043.44 l/d in 2019, a growth in groundwater demand of 168%. In addition, the groundwater demand was projected to increase to 145,235,374.23 l/d when full commercialization of the oil fields begins, representing 2,833% water demand increase between 2019 and 2022. It was observed that 58% of the overall groundwater demand was utilized for oil production in 2019 and this was expected to increase to 99% in 2022. The study showed that the average daily groundwater levels remained constant with Chinese 1 and Nawoyatira boreholes registering average daily water level of 18.12 m and 19.5 m respectively. However, there were major changes in hourly groundwater levels with the highest levels being recorded in the morning and the lowest levels being recorded at noon (2:00 pm). The level declined from 8:00 am when pumping commenced up to 2:00 pm after which the levels would start rising again. The decline in water levels worsened upon the incorporation of the oil production water demand into the abstraction, with levels at Chinese 1 reducing to a low of 74 m and Nawoyatira reducing to a low of 61 m. Therefore, the study concluded that increased groundwater abstraction led to borehole water level decline.