USDA: Low water levels observed on Lake Victoria

Report
from Government of the United States of America
Published on 26 Sep 2005


Production Estimates and Crop Assessment Division
Foreign Agricultural Service

The Foreign Agricultural Service's (FAS) Global Reservoir Monitor indicate very low lake levels in Lake Victoria, the largest lake in Africa and major reservoir for the Nile River. Water levels have remained above-average for more than 40-years, but current water levels are below normal and the lowest level since September, 1961. The lake typically recharges during the upcoming “short rains” (October-December) and “long rain” (February-June) seasons, but the amount of recharge this year will be dependent on upcoming seasonal rainfall amounts and if Uganda’s power utility does not release too much water for power generation.




In addition, FAS monitors the water levels for nearly 80 lakes worldwide with satellite radar altimeter and these measurements were compared to water level gauge measurements taken on Lake Victoria near Jinja, Uganda from 2000-2004. The results show that the water levels measured by satellite radar altimeter and water-level gauges are very similar, and these near-real time satellite measurements will be very useful to monitor critical water-levels on Lake Victoria in the future.

Water levels of Lake Victoria are extremely sensitive to moderate changes in rainfall over the lake and rain catchment basin, with the lake’s large surface area making it the largest recharge source. The lake’s only outlet is at Ripon Falls, located near Jinja Uganda, which is the natural topographic control that originally formed the lake. In 1954, Owens Falls Dam (later renamed Nalubaale) was commissioned downstream of Ripon Falls to generate hydroelectricity along the Victoria Nile river and became Uganda's largest power station. Several years later in late 1961 and early 1962 (not an El Nino year), East Africa and Lake Victoria received above-normal rainfall and the lake unexpectedly rose 2.5 meters following a long period of near constant levels from the turn of the century. The hydrology of Lake Victoria subsequently received lots of research attention and these hydrologic studies later linked the rapid rise in water levels due to unusual abundant rainfall over Lake Victoria and East Africa during 1961-1964. Correspondingly, the operating rule curve at Owens Falls was adjusted to maintain “equilibrium” water level for the past 40-years at approximately 11.9 meters. However, recent operating practices have exceeded past sustainable operating water levels because the Nalubaale power station was recently expanded by the Owens Falls Extension (later renamed Kiira) power station located about one-kilometer from the Nalubaale power station. The increased hydropower capacity at Nalubaale and Kiira power stations allowed more water to be released for power generation and recently lowered lake levels to unsustainable levels below 11 meters.

In addition, the local press from Uganda and Kenya recently reported about the low lake levels for Lake Victoria. The Ugandan press (Daily Monitor, September 13-19, 2005) reported that Uganda has had power shortages for the past five months due to the drastic lowering of lake water levels, and thus reducing the hydropower output along the Victoria Nile River at Kiira and Nalubaale power stations. The Kenyan press (East African Standard, August 22, 2005) reported that low water levels have forced ships to dock in deeper waters located away from the shores, affecting inland water transport, agricultural markets, and trade between Uganda, Kenya, and Tanzania. The press article also mentioned that local fisheries have been affected from the low lake water levels.

Lake Victoria is bordered by Kenya, Uganda, and Tanzania and is one of the most highly populated areas in the world and the surrounding basin is intensely cultivated. The lake serves as a valuable resource to the region providing potable water, hydroelectric power, inland water transport, and supports many different industries such as agriculture, trade, tourism, wildlife, and fisheries. It is estimated that the basin serves as a major source of employment for some 30 million people, of which approximately 3 million people are engaged, directly or indirectly, in subsistence and commercial fishing and more than 80 percent of the populations engaged in agricultural production, with the majority being small scale farmers and livestock owners. The main crops produced are maize, beans, sorghum, millet, paddy rice, and cash crops such as sugarcane, tea, coffee, cotton, and meat. In addition, inland water transport on Lake Victoria serves as alternative transport routes for movement of passengers and commodities such as fuel, cotton, and grains, with main ports located at Kisumu, Kenya; Mwanza and Bukoba, Tanzania; and Entebbe, Port Bell and Jinja, Uganda.

Ironically, many of the local communities living near Lake Victoria's unique and vast natural food resource are among the poorest and most food insecure in the region due to high population densities, widespread poverty, recurrent droughts, crop failures, high mortality rates (from tuberculosis, malaria, and HIV/AIDS), and environmental degradation (contamination, pollution, land/forest degradation, biodiversity degradation, introduction of exotic species, i.e.) from the lake being the final recipient of human and industrial wastes and eroded soils. For example, agricultural production in all lakeshore districts declined in the early and mid-1990s, making the region a net importer of most farm produce.

Uganda’s Enormous Hydropower Potential

As a way to reduce poverty and promote economic growth, the Ugandan government in the 1990’s encouraged investment in the hydropower sector especially in the rural areas where over 90 percent of the population is found. Five priority hydropower projects were proposed by the Uganda government which include the renovation and expansion of the Nalubaale dam from 180 MW (10 units of 18 MW) to 380 MW (with Kiira power station producing 200 MW), Bujagali hydro facility (200 MW), Karuma dam (100–200 MW), and a number of smaller hydropower projects. The new Kiira power station located about one-kilometer downstream from Nalubaale was inaugurated in 2000 and was targeted to meet additional power demands from Uganda’s growing economy. The Kiira station has 3 units of 40 MW (120MW) with another 2 units of 40 MW currently being installed. Further downstream is the Bujagali (290 MW) hydroelectric power scheme which is currently being constructed and will open in 2009 at the earliest. In addition, Uganda is currently seeking funding to finance the Karuma (100-200MW) hydro project.

Uganda has enormous hydroelectric potential along the Nile River, but only a fraction of Uganda's hydroelectric potential has been developed. Currently, the country's power demand is greater than supply with just 3-5 percent of the population having regular access to electricity and many towns not having any power supply, especially in the north. The lack of hydropower development in Uganda can be largely attributed to political instability during the 1970’s and 1980’s, but Uganda’s economy has been growing since the late 1980's. By the 1990's, economic growth in many sectors throughout Uganda was constrained by insufficient power capacity and unreliability of the country’s largest hydropower station at Nalubaale.

Preliminary estimates measured the Nile River's hydroelectric potential at 8000 MW and Uganda's hydroelectric potential along the Victoria Nile River estimated at nearly 2000 MW, with the 180 MW capacity at Nalubaale in 1999 comprising less than 10 percent of Uganda's hydroelectric potential. In comparison, it is estimated that the East African region currently has an installed capacity of 1800 MW. The Nile Basin Initiative (NBI) proposes to further develop the hydropower potential along the Nile basin and promote the economic development for the region with rural electrification. Special concentration will also be given to hydropower development of the high-potential Lake Victoria region through the Nile Equatorial Lakes Investment Program (NELSAP). The Uganda government is involved with these regional development plans and they privatized their power utility company in 1999 to place them in better position for private investment and receive international financing for additional hydropower development.

For more information, contact Curt Reynolds with the Production Estimates and Crop Assessment Division, at Curt.Reynolds@fas.usda.gov or (202) 690-0134.