precipitation and hydroelectric power

Gibe III; from peak water.

Construction on the Gibe III Dam in Ethiopia, the fourth largest dam in the world, began in 2006 and is a highly controversial hydroelectric project. Ethiopia should earn over $400 million annually from power exports, much of which will be exported to Kenya. Environmentalists claim that construction of the dam will further reduce human-available water supply in the already drought-stricken Gibe III region, which spans Ethiopia and parts of Kenya, as well as drastically reduce water levels in Lake Turkana in Northern Kenya. Dam-induced water shortages will be exacerbated by the erratic rainfall patterns predicted by climate change. Widespread protests over dam construction reflect disenchantment with both dams and hydroelectric power generation across Kenya, in part due to increasingly variable rainfall under climate change.

A child fishing on Lake Turkana, in Northern Kenya. Fishing
is an important source of income in this region and will likely
be hurt by the construction of Gibe III. 

Movement away from hydroelectric power coincides with increased power needs in Kenya due to  booming populations and higher per capita demand for electricity. Currently, less than 20% of Kenyans (and only 5% of rural Kenyans) have access to electricity, and frequent rolling blackouts due to electricity shortages are common throughout the country. Many businesspeople say that blackouts are one of the key barriers to economic growth.

In the face of the country's desperate need for energy, however, the source of this energy is in flux. Historically, most power production in Kenya has been hydroelectric, with dam-generated power supplying over 80% of the country's electricity at its peak. The largest power producer in Kenya, Kenya Electricity Generating Company, is curtailing its output from hydropower, choosing instead to rely more on other sources of renewable energy such as solar and geothermal. The company indicated that this shift will reduce their dependency on often erratic weather for power generation. With precipitation slated to become even more erratic, it is essential to diversify modes of power generation in Kenya in order to keep up with rising demand.

Climate change projections for the region suggest increased mean rainfall and increased variability in rainfall. While increased rainfall in the region could lead to increased capacity for hydroelectric power, due to the increasingly erratic rainfall patterns, higher electricity generation is likely unfeasible for most large dams. One approach to generate hydroelectric power from increased rainfall would be to increase storage capacity in existing dams, but this is an expensive endeavor. Some dams have successfully modified timing of discharge to accommodate increased variability in rainfall, but these approaches require substantial data on in-stream flow rates. Coupled with uncertainty in the predictions of rainfall amounts and variability, this approach seems too data-intensive for the majority of dams in Kenya.

A small hydroelectric dam in Kenya, from treehugger.com

While large-scale power generation on the Gibe III scale may be a thing of the past in Kenya, small power generation (~500 KW generation) can be used to help the government's efforts to increase rural access to electricity, and excess energy can often be given back to the National Grid. While these projects have a high installation cost, and often suffer from inadequate data on water flow in rivers, they can help increase electricity generation in rural areas that have not historically had energy. In addition, these efforts can help provide a source of water during dry seasons, mitigating the agricultural effects of increased variability in precipitation.

As Kenya moves away from large-scale power generation via hydroelectric power, toward energy production that is less dependent on erratic rainfall patterns, large dams may become less and less common. Given high variability in rainfall that has led to closing of hydroelectric dams due to low water availability, these changes will likely lead to a more consistent electricity supply, increasing Kenya's economic prosperity. In my next post, I will discuss how Kenyans are coping with changes in precipitation patterns in the context of another important component of Kenya's economic prosperity, rainfed agriculture.

current and future floods in Kenya

Recent flooding in Kenya in April 2013 led to 62 deaths and almost 90,000 displaced people.  Heavy rains during the March rainy season resulted in many riparian flooding events, washing away villages and agriculture along many of Kenya's waterways. These events have led to substantial pressure on the Kenyan government to improve its response to such flooding events and flood control.

Disaster aid during the April 2013 floods, from the
Facebook page of the Kenya Red Cross Society.

These most recent floods are part of a string of large floods in the past 20 years. The 1997/1998 floods affected almost 1 million people, with economic costs of $0.8 to 1.2 billion. Another 2006 event affected over 723,000 Kenyans. In a recent survey on flooding events in Kenya, 96% of respondents said that floods have become more frequent or intense over the past 20 years. Flash floods occur in both rural and urban areas, most commonly in river valleys, marshes, lakeshores, and along the coasts, during either the short and long rains. High vulnerability to floods can be exacerbated by high poverty, poor land use patterns (such as deforestation, agriculture, and settling along river banks), low education and literacy, and low levels of infrastructure. 

In addition to land-use practices, climate change has likely contributed to this increase in flood frequency and severity, and flood risk will only increase in the future. Many models indicate an intensification of heavy rainfall in the wet season; this intensification will lead to greater flood risk, with more significant floods occurring more frequently

Floods can devastate both local and national economies. Even in the absence of climate change, population and economic growth (particularly in riparian areas) will increase the costs of flooding events by a factor of 5 by 2030. Climate change will only compound these costs: because flood damage costs rise very sharply with flood depth and strength, a higher frequency and intensity of flooding events with climate change will drastically increase these costs. Costs include mortality, damage to infrastructure (roads, buildings, and communications), public health, loss of crops, as well as undocumented effects on rural populations and the non-formal economy. Costs can also include ecological damage: coral reefs in Mombasa, a popular coastal tourist destination, were highly damaged by the 1997/1998 floods, with 50% of coral reefs in nearby Malindi killed by light limitation arising from sediment deposition, hurting the tourism in this region. 

A coral reef on the Kenyan coast. Image from the
Smooth Guide to the Kenya Coast.

The Kenyan government's response to flooding events has focused on post-flooding relief, as well as prevention of future flood damage. Post- flooding relief has been the government's main focus, but such relief efforts have been poorly coordinated and unnecessarily expensive, likely due to the lack of a disaster management policy, as well as the government's lack of response to early warnings. Governmental post-flood efforts have focused on distributing food, but other critical components of the response, such as healthcare, have been neglected due to lack of funds, lack of roads, and absence of infrastructure in rural areas. Governmental efforts to prevent and control flooding via dam construction have also suffered from inadequacies. A recent United Nations Report highlighted that poorly-designed dams in some regions of Kenya have led to seepage and backflows of water. Many of these dams are more than 20 years old and must be repaired or replaced soon.

In an effort to address shortcomings with preventing, controlling, and responding to flooding, in April 2013, the Kenyan government announced the establishment of a national disaster management authority. This program will help coordinate multiple institutions' disaster prevention and response, hopefully leading to a more efficient, effective, and integrated disaster management system. In addition, this program will develop a five-year plan to build dykes and dams to curb flooding. In addition to flood relief and prevention, this group will likely focus on improving both forecasting of flood events, as well as improving warning systems for communities in flood areas.  

Flooding in Bunyala after a dam failed; many of the dams in
this region are quite old, some up to 40 years. Image from IRIN.

In addition to a national response, work on improving flood resiliency at the local level has also helped mitigate flood damage. Local communities in some areas are working together to raise the level of dykes in order to hold the increased precipitation coming from climate change. Additionally, farmers in many areas have also been working to diversify the livestock they keep in an effort to minimize flood damage. Finally, some riparian communities have been trying to change infrastructure, such an putting houses on higher ground, in an effort to withstand floods.  

While floods in Kenya are a substantial problem, and will likely only increase in frequency, intensity, and cost in the future, both governmental and local efforts to mitigate and prevent future damage will likely help improve flood control and response. While this post has outlined how floods can be a disastrous problem in Kenya, my next post will discuss how increased river flow can also be beneficial: I will discuss how increased river flow arising from increased precipitation might help Kenya's energy sector.