NAKIVUBO SWAMP, UGANDA: Managing Natural Wetlands for Their

started toworkcloselywithurbanplanners. of citylandscapesandservices. managing themasanintegrated component programmes, and to pointwaysof wetlands aspartofurbandevelopment wetlands managementinUganda national government agencymandatedwith − complete pictureoftheeconomicdesirability more a give valuation isbeingusedto Africa, Eastern in times For oneofthefirst of Water,LandsandEnvironment Inspection Division of theUgandaMinistry Wetlands The are beginningtochange. planning urban out Slowly, waysofcarrying km Wetlands inUgandacoversome30,000 Uganda Planning forurbandevelopmentin services for theirecosystem managing naturalwetlands UGANDA: NAKIVUBO SWAMP, VALUATION #7:May2003 CASE STUDIESINWETLAND 1996). wetland drainageandreclamation(NEMA involved have planning andcontrols, proper implemented intheabsenceof date, most of thesedevelopmentshavebeen and commercial activitiesareincreasing.To construction istakingplace,andindustrial housing andlandforsettlement,rapid 1999). There isagrowingdemandfor the averageinruralareas(UN-HABITAT year a 5% a rateofmorethan at increasing cities, andurbanpopulationsare in live inhabitants over 14%ofthecountry’s rehabilitation andurbanexpansion.Already period ofrapideconomicgrowth, Over the lastdecadeUgandahasentereda face the perhapsmostintensepressures. cities some way,thoselocatedintownsand in threat wetlands inthecountryareunder the Uganda 2001).Althoughalmostallof or about 13%ofthecountry(Government andlong-termviability − of reclaiming of − almosttwice − − has the 2 , Integrating Wetland Economic Values into River Basin Management km2. The wetland is fed by the Nakivubo River and its tributaries the Katunga, Kitante, This case study describes a pilot study carried Lugogo and Nakulabye. It is dominated by out in Nakivubo Swamp in Kampala, Uganda’s papyrus (Cyperus papyrus) grading to dry land capital city, which focused on the economic through cat tails (Typha sp.) and common reeds value of wetland wastewater purification and (Phragmites sp.), with a large area on the north nutrient retention functions. The study made east side covered by Miscanthidium grass. The the point that, contrary to the dominant wetland is bisected by a railway line, running development imperative, residential and from the city to Port Bell on the shore of Lake industrial development in Kampala’s wetlands Victoria. This effectively divides it into two does not necessarily make good economic zones of human influence. While wetland areas sense, and cannot be based only on to the south of the railway are still relatively consideration of immediate financial gain. intact, northern parts have been modified These expectations of private profits also have substantially. Much of the shallow upper zone to be balanced against the broader social and has been reclaimed for settlement and economic costs which arise from urban industrial development, or is under cultivation. wetland degradation and loss. The deeper, lower zone below the railway line comprises a floating papyrus swamp, and Nakivubo Swamp contains only a small amount of cultivation on its fringes. Almost one sixth of Kampala, or 31 km2, is covered by wetlands (Mafabi et al 1998). The wetland runs from the central industrial Despite the designation of most of the city’s district of Kampala, passing through dense wetlands as “green corridors” in the 1994 residential and industrial settlements before Kampala Structural Plan, many have been entering Lake Victoria at Murchison Bay zoned for urban expansion and development (Figure 1). More than 100,000 people live on and have either been converted to industrial the fringes of the wetland, including both high uses or have gradually been taken over by cost housing estates and low-cost, high-density settlement (Government of Uganda 2001). settlements and slums. To the north of the Today it is estimated that about three quarters wetland, Kampala’s main industrial area of the city’s wetlands have been affected by human activities to a significant level, Figure 1: Location of Nakivubo in Kampala District and up to 14% are seriously degraded Mbuya INDUSTRIAL AREA (Muramira and Namirembe CITY Bugolobi Emerton 1999). If CENTRE current trends continue, there is a Nsambya Luboga Mengo real danger that Port Bell Kampala’s Ndeeba Muyenga wetlands will soon Kansanga Inner be modified and Najamkumbi Murchison converted Bay completely. Makindye Lake Victoria Gaba Of the twelve main wetland areas of Kampala District the city, Nakivubo Nakivubo Swamp Swamp is the Nakivubo Channel and tributaries largest. Covering a Roads surface area of 5.29 Railway Nakivubo 2 km , it has a total Swamp catchment extending over 40 contains more than 200 large, medium and effluents already in the Nakivubo Channel small-scale enterprises. These include before entering the wetland, where it breweries, soft drink manufacturers, distillers, contributes about 7% of the total nutrient load, oil and soap factories, dairy producers, equivalent to an additional flow of sewage from abattoirs and meat processors, fish processors, about 7,000 persons (COWI/VKI 1998). paint producers, tanneries, bakeries, metal works and garages, plastic and foam industries, The majority of the low-cost residential saw mills, battery manufacturers, settlements abutting Nakivubo are excluded pharmaceutical industries, shoe makers and from the municipal sewerage system. More paper makers. Although like most wetlands in than 33,000 persons discharge domestic wastes Kampala Nakivubo has been subjected to a into the wetland, either as runoff into the gradual process of conversion and reclamation, surface waters which enter it or through it currently faces some of the most extreme groundwater inflows from the infiltration of threats and pressures. The area around rainfall on hills beside the swamp, from pit Nakivubo, including the wetland itself, are latrines, septic tanks, soak pits and leaking regarded as prime sites for urban development waste pipes. At least three other point sources − due to their proximity to the city centre and of wastes enter southern parts of the wetland industrial district, as a result of land shortage in directly, including effluents from Uganda the city, and because land prices are still Breweries and two sewage outflows from relatively cheap as compared to other parts of Luzira Prison. Nakivubo Swamp also receives Kampala. industrial effluents. Up to a third of the enterprises in the industrial area have no treatment facilities, and so dispose of their The role of the wetland in wastes directly into the wetland. Effluents and wastewater purification and nutrient pollutants contained in these untreated retention wastewaters, and in the industrial wastewaters which have passed through Bugolobi sewage Nakivubo’s characteristics and location means treatment works, include detergents, lubricants, that it provides a unique and important set of oils, acids, xenobiotics, nitrates, phosphates services to Kampala’s dwellers. It functions as a and heavy metals such as zinc and mercury. buffer through which much of the city’s industrial and domestic wastewaters pass At the same time, the intake for all of before being discharged into Lake Victoria at Kampala’s piped water supply is located at Murchison Bay (Figure 2). The Nakivubo River Gaba, some 3 km to the south west of the and its tributaries, which flow into the wetland, provide the main drainage channel for Kampala. They Figure 2: Wastewater loads entering Nakivubo carry wastewater from the city centre, industrial area, Nakivubo Channel and residential zones. Up to Industrial district 90% of Kampala’s residents High-cost housing are not connected to a Low-cost housing piped sewerage supply and so these wastes are largely Bugolobi organic. Together they are Sewage equivalent to the raw sewage produced by almost half a million people − or 40% of the population of Nakivubo Swamp Kampala (COWI/VKI 1998). The outflow for Kampala’s sewage treatment Gaba works, at Bugolobi, also Water runs into the wetland. LAKE VICTORIA Partially treated sewage is mixed with the untreated wetland’s outflow into Murchison Bay. supply equivalent wastewater purification and Nakivubo plays a significant role in maintaining nutrient retention services through other the quality of both the city’s water supply and means. The study focused on assessing the the open waters of the Murchison Bay part of value of Nakivubo in treating domestic wastes, Lake Victoria. The wetland has a high nutrient as they contribute by far the greatest quantity retention capacity, and is effective in removing of wastewater and highest proportion of the bacteria and microbes. It physically, chemically total nutrient load entering the wetland, both at and biologically eliminates pollutants and the present time and for the foreseeable future. sediments from the wastewater which passes Industrial wastes, although containing much through it, and reduces the pollution load higher concentrations of toxic substances, entering Inner Murchison Bay through currently add less than a quarter of total mineralisation and sedimentation processes. Of nutrients, and only yield low loads of heavy particular significance is the capacity of wetland metals, BOD and COD. plants to remove phosphorus and nitrogen, the accumulation of suspended solids, pollutants Replacement costs included two components: and pathogenic organisms in the wetland’s connecting Nakivubo channel to an upgraded bottom sediments and their decomposition, the Bugolobi sewage treatment plant which could conversion of

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