Responsible Water Resources Management in a Semi-Arid Region of Kenya using Techniques from Public Water Utilities

Abstract

Tullow Kenya BV, with joint-venture partners, holds the exploration licences for several onshore blocks in Turkana, northern Kenya, and an exploration/appraisal drilling programme is well advanced. Turkana is one of the driest parts of Kenya, so finding, developing and managing water supplies presents many challenges. The challenges have been solved by applying methods and procedures from the water utility industry; the way in which this has been achieved is explained.Water is required by Tullow for drilling, field camps, civil engineering and community water supply. Larger quantities of water will be required in the future for reservoir injection. Water supplies to meet current demand are provided by a dispersed network of boreholes, exploiting groundwater in local shallow aquifers. Water is distributed from sources to demand centres by a combination of pipelines and tanker trucking. The demand centres include permanent installations but also many short-term sites. Matching supply from widely-scattered sources, with different yields and water qualities, to ever-shifting patterns of demand is the same puzzle faced by public water utilities.Key indicators used in the water sector include: deployable output, outage, water available for use, headroom and potential yield, and these have been successfully applied in Turkana. The application of water resources management and reporting procedures from the water utility industry to an oil operation in a region that is semi-arid, remote and insecure, with fierce competition for scarce water resources, has proven to be a powerful technique. Given that most of the source boreholes yield relatively fresh water, there is a big responsibility on Tullow to use water wisely and to be able to demonstrate that it is doing so. The techniques also allow plans to be made for when and where new water sources (from groundwater and surface water) need to be brought on stream to stay ahead of the demand curve.Yields from individual water sources vary considerably with the seasons and from year to year. Defining the long-term sustainable yield of any particular source is not straightforward and must be done using a standard technique if the results are to have any value for comparison, reporting or auditing. Tullow has addressed this and other water resource management issues by the novel approach of treating its operations in Turkana as if it were a water utility.

Analysis of the impact of hydraulic properties and climate change on estimations of borehole yields

“…Kenya (Boak, 2016), but only the UK provides detailed methods and guidelines for borehole yield assessment under drought and climate change impacts (UK Water Industry Research Ltd, 2014).…”