Zambezi Heartland Watershed Assessment

A Report by Craig Busskohl (U.S. Forest Service), Jimmiel Mandima (African Wildlife Foundation), Michael McNamara (U.S. Forest Service) and Patience Zisadza (African Wildlife Foundation Intern). © Craig Busskohl The African Wildlife Foundation, together with the people of Africa, works to ensure the wildlife and wild lands of Africa will endure forever.

ACKNOWLEDGMENTS: AWF acknowledges the technical assistance provided by the U.S. Forest Service to make this initiative a success. AWF also wishes to thank the stakeholder institutions, organizations and local communities in , and (ZIMOZA) for their input and participation during the consultation process of this assessment. The financial support AWF received from the Netherlands Ministry of Foreign Affairs/ Directorate General for International Cooperation (DGIS) is gratefully acknowledged. Finally, the authors wish to recognize the professional editorial inputs from the AWF Communications team led by Elodie Sampéré. Heartland Watershed Assessment Aerial Survey of Elephants and Other Large Herbivores in the Zambezi Heartland: 2003

Table of Contents

1. Introduction page 4 Preliminary Assessment page 4 Project Objective page 4 Expected Outputs page 4 Zambezi Heartland Site Description page 5

2. Key Issues, Concerns, and Questions page 6 2.1 Overview page 6 2.2 Key Issues page 6 2.2.1 Impact of Farming Along Seasonally Flowing Channels page 7 2.2.2 Impact of Farming Along Perennially Flowing Channels page 7 2.2.3 Future Development of Farming page 7 2.2.4 Settlement Rates page 8 2.2.5 Streambanks Developments page 8 2.2.7 Fisheries Resources Below Kariba Dam page 8 2.2.8 Riparian Areas Below Kariba Dam page 8 2.2.9 Geomorphology Below Kariba Dam page 8 2.2.10 Sediment page 8 2.2.11 Luangwa River Fisheries page 9 2.2.12 Soil and Water Conservation page 9 2.2.13 Fire page 9 2.2.14 Water Quality page 9 2.2.15 Groundwater page 9 2.2.16 Springs, Ponds and Vernal Pools page 9 2.2.17 Shifting Agriculture page 9 2.2.18 Species and Habitats page 10

3. Characterization, Existing Condition and Discussion page 11 3.1 Human Uses page 11 3.2 Species and Habitats page 12 3.3 Vegetation Cover page 12 3.4 Erosion Processes page 13 3.5 Geology page 13 3.6 Soils page 14 3.7 Hydrology page 15 Surface Water Hydrology page 15 Human Impacts to Stream Channels page 16 Wetlands, Springs and Ponds page 16 Impacts of Kariba Dam page 17 Groundwater Resources page 19 Metereology page 19

4. References Conditions page 19

5. Summary and Recommendations page 20

6. References page 22

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1. Introduction project will be to gain increased understanding of the problems affecting these watersheds and The African Wildlife Foundation (AWF) and to provide data, information, and analyses on U.S. Forest Service (USFS) International watershed conditions of the Zambezi landscape. Programs initiated a partnership to protect forest, Consequently, a decision was made to focus soil and water resources in critically important resources on one site, the Zambezi Heartland, a African landscapes. USFS is providing technical three-country trans-boundary landscape in expertise to better understand the watersheds . in selected large-scale conservation landscapes in Africa, AWF’s African Heartlands. African Project Objective Heartlands are large African landscapes of exceptional wildlife and natural value where Through AWF’s Heartland Conservation AWF works with a variety of partners, including Planning (HCP) process for the Zambezi local communities, governments and other Heartland, hydrological systems such as the resource users to conserve wild species, Zambezi River and its (inclusive of ecological communities and natural processes. the artificial reservoirs therein) were identified Many of the conservation targets that AWF has as important conservation targets in this identified are closely linked to forest and landscape. The main objective of this project watershed processes. USFS and AWF recognize will be to conduct a detailed assessment of these the benefit of working to address watershed hydrological systems in order to determine the degradation in these globally significant African conditions of these catchments and to landscapes. characterize threats and subsequent strategies to abate threats to these systems. There currently is a lack of systematically and consistently Preliminary Assessment collected basic information on hydrologic In July 2003, USFS Africa Program made a components of these systems such as preliminary visit to Zambezi Conservation precipitation, stream flow regime, water Center and met with AWF staff responsible for abstractions, cover conditions, and channel/ the Kazungula and Zambezi Heartlands. The riparian condition. Another area that needed purpose for the trip was to discuss possible expert to be better understood is the relationship requirements in view of the USFS’s experience between local land use regimes and hydrological working with AWF on Watershed Assessments conditions. in East Africa and to determine if the USFS could provide assistance to AWF in addressing those Expected Outputs issues. The meeting resulted in AWF identifying It is envisaged that the information collected the need for the following assessments to inform through this process will be used by all parties adaptive conservation intervention strategies in involved in the project to assist in the following: the Zambezi landscape: § Land use planning and implementation; § The water balance of the key watersheds § Information to users to adopt in Zambezi Heartland are not well appropriate agricultural methods; understood or documented. § Enforcement of water laws where § The relationships between various land necessary; use practices and impacts on the water § Educational campaign targeting balance do not appear to be well upstream users; and understood. § Information to affect changes in policy The scientific basis for understanding land use and institutional mechanisms for water effect on the water balance and water quality users rights. does exist, through work of Zambezi River Authority on a long stretch of the Zambezi The assessment is expected to result in the River. As such, a major component of this following:

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§ Assemblage of existing data and analyses protected land from Kariba Dam almost to the in order to address key questions related Mozambique Border including areas such as to the river; review of quality control Mana Pools National Park which is a World and quality assurance of water data. Heritage Site, large public safari areas leased to § Detailed assessment of the Luangwa and the private sector as hunting and tourism upper reaches of Cahora Bassa reservoir; concessions (the Charara, Hurungwe, Chewore, characterize existing watershed Dande and Doma Safari Areas), and vast conditions of the river including communal lands on the periphery of these attributes such as precipitation, stream- protected wildlife areas (Hurungwe, Mkwichi flow, water abstractions, cover and Guruve Communal Lands). The National conditions, and channel characteristics. Park and Safari Areas are state lands under the § Documentation of current river jurisdiction of the National Parks and Wildlife condition compared to a reference Management Authority (NPWLMA) (formerly condition that can provide a basis for the Department of National Parks and Wildlife describing desired future condition. Management). § Understanding and documentation of water balance of these watersheds In Zambia the Lower Zambezi National Park is including defining watershed boundaries a protected wildlife area extending across or contributing areas. and Luangwa Districts and administered by the § Quantification and documentation of Zambia Wildlife Authority (ZAWA) and is abstraction flow. flanked by the Chiawa GMA in the south and § Further assessment of the relationships the Rufunsa GMA in the north. The GMAs have between various land-use practices and some measure of wildlife protection as buffer impacts on the river system. zones between parks and open communal areas § Definition of cover type/land-use and they are under the jurisdiction of local characteristics of the watershed.

Zambezi Heartland Site Description The Zambezi Heartland is a three country, trans- boundary landscape that includes a range of extremely biodiverse landholdings along the middle stretch of the Zambezi River. Geographically, it covers an area of approximately 47,000 km2, consisting of 6,495 km2 National Parks, 4,885 km2 Game Management Areas (GMAs), 11,244 km2 Safari Areas, and the rest are open communal areas. In Zimbabwe much of this area is

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chieftaincies but ZAWA has a mandate over the Institutions and researchers and other wildlife resources. institutions have gathered and analyzed large amounts of primary data in order to formulate The core open areas (communal) in the prescriptions and in some cases implementation Heartland are on the border between Zambia, has already commenced. Prime examples of this Mozambique and Zimbabwe, covering the are the Community Based Natural Resources Luangwa district in Zambia, Zumbo and Mague Management (CBNRM) initiatives in the districts in western Mozambique, Zambezi Heartland in which concepts of and Lower Guruve district in mid-Zambezi judicious land use planning are followed. These , Zimbabwe. Other human settlements are are the Tchuma Tchato program in Mozambique, located in the GMAs on the Zambian side, and the CAMPFIRE program in Zimbabwe and in the Hurungwe and Mkwichi communal areas ADMADE in Zambia These programs seek to in Zimbabwe. The total human population in empower local stakeholders to co-manage the the site is approximately 120 000, the majority natural resources in their area and share both of which derive their livelihoods from subsistence costs and benefits of the land uses practiced. agriculture and livestock husbandry. Because of the nature of livelihood economic activities, the Furthermore, central government departments area is threatened by land degradation as a result with mandates over watershed and/or catchment of forest removal for agriculture, construction management exist on the ground, albeit with timber and fuel, high livestock densities, limited resources. This includes departments of especially goats, and bush fires set by poachers. Water Affairs or Water Authorities, Natural The situation is exacerbated by undefined land Resources, Forestry, Agriculture, Fisheries, etc tenure rights (especially in Mozambique), and as well as the bilateral institution, Zambezi River growing population density. Authority (ZRA). All these have scattered data and information relevant to watershed In terms of biodiversity richness, the protected management and if pooled together, could be wildlife areas in the Heartland incorporate some useful reference for assessment and improved of the most outstanding terrestrial and riverine management. wildlife viewing and scenic landscape in Southern Africa. This means that the initiative by AWF in collaboration with the USFS is set to build on what already exists and needs to dwell more on 2. Key Issues, Concerns, and Questions putting together existing secondary information on the watershed before starting to gather 2.1 Overview primary data. This will allow for identification Through information gained from field surveys of gaps and will also facilitate participation of and discussions with partners, the team identified different players from relevant institutions in the and described ecological processes of greatest three countries. concern and established how well or poorly such processes may be functioning. From this 2.2 Key Issues information, the assessment has identified a list A primary concern in several watersheds in the of key issues and concerns. For issues where the assessment area is the impact land use practices team felt more data, information, or observations are having on river and stream systems in the were needed questions were suggested for issues Zambezi Heartland. AWF and the USFS hosted requiring additional information needs. three stakeholders workshops to gather information from stakeholders who are living in As progress has been made with partners who the Zambezi Heartland to help understand the are working in the region, it is clear that much issues and key questions affecting land information already exists on the current management and human use. The gathering of conditions and problems affecting the Heartland.

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partners and stakeholders to discuss the compliance with existing government policies assessment was useful for hearing from local land regarding streambank farming. managers and validating ecological assessment efforts. One of the main focuses 2.2.2 Impacts of Farming of the workshops was to identify Along Perennially Flowing © Michael L. McNamara and agree on the issues and key Channels questions that are affecting These are usually small watersheds in the Zambezi subsistence farms, and often they Heartland. reach to the edge of the river or . They are common Of particular concern is the along portions of the Zambezi floodplain agriculture river in Zambia and Zimbabwe, expansion and development and along the Luangwa River in along perennial and seasonal Zambia and Mozambique. It is tributaries and the main-stem likely that streambank farms are Zambezi River, effect of a loss a source of sediment to the , of floodplain function and and they eliminate riparian riparian vegetation from dam- vegetation, expose bare soil to regulated flows in the Zambezi erosion, contribute to streambank river below Kariba Dam, and instability, deplete the nutrient observed soil erosion and capital in the soil, and gullying along the Zambezi detrimentally impact fish habitat. River. Another concern is the Detailed surveys should be uncertainty regarding the conducted to determine the combined effects of safari lodges short-term and long-term impacts and other development on of streambank farms to the water quality and stream Luangwa River Floodplain, Zambezi Heartland Luangwa and Zambezi Rivers, and morphology along the Zambezi to determine how well existing River. policies regarding streambank farms are being enforced. 2.2.1 Impacts of Farming Along Seasonally Flowing Channels 2.2.3 Future Development of Farming Erosion from farms along seasonally flowing Given the scenario described in sections 2.2.1 channels is a key issue in the Luangwa River area and 2.2.2, key questions that arise regarding the that forms the natural border between Zambia future development of farming are as follows: and Mozambique, and in portions of the Zambezi § Are there better ways to accommodate River in Zambia and Zimbabwe. Accelerated farming in the Zambezi Heartland erosion is thought to be a major source of riverine valleys? sediment to the Zambezi and Luangwa rivers and § Are there off-channel water their perennial tributaries. Farms tend to be development opportunities such as small subsistence plots, and tend to span the irrigation or boreholes? channels, often time leading to severe gullying § What is the carrying capacity of this arid and bare mostly unprotected stream banks. The landscape for farming? relative contribution of streambank farms along § Are there other livelihood opportunities seasonal channels to the sediment load delivered different from agriculture that can to downstream channels is unknown. Detailed provide work and employment for local surveys need to be conducted to determine the communities? relative sediment sources, and to assess

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analysis, an understanding of the relationship between fish species life history and river 2.2.4 Settlement Rates hydrology is lacking in the Zambezi landscape. It was apparent from the field excursions that In particular, it is essential to understand how the extent of settlement and population density the dam altered the fishery and how current dam in this area was generally low. However, as operations to satisfy power utility needs are episodes of drought become more recurrent, meeting environmental /ecological low there is a high likelihood for more pressure for requirements. It will be necessary to employ a settlement along the limited water channels in water release strategy that is more favorable to the Zambezi Heartland. It is therefore essential protecting fish and other aquatic species. to forecast the expected settlement rates along the Luangwa and Zambezi Rivers in the future 2.2.8 Riparian Areas Below Kariba Dam and explore the possibility of directing Gullying and a high percentage of bare soil and settlement toward preferred areas. a lack of understorey vegetation was observed in many areas from below Kariba Dam to Big 2.2.5 Streambank Developments Five safari Camp, especially on the Zimbabwe Numerous safari lodges are located immediately side. Drivers for this situation are not clear and adjacent to the Zambezi River especially in the seem to speculatively be attributed to uneven Chiawa Game Management area where an wildlife distribution and densities. This requires excess of twenty-four units are operational. The further holistic investigations that examine the impact of these lodges to water quality, bank multiple variables at play. stability, and wildlife habitat is not known and needs to be investigated. It is also essential to 2.2.9 River Geomorphology Below Kariba check compliance to provisions of Dam environmental legislation in the respective The creation of the reservoir at Kariba obviously countries. resulted in alteration of the flood regime of the river downstream. However, it is not clear 2.2.6 Riparian Areas and Water Management whether the impact of dam operations on river Below Kariba Dam morphology has been documented and The aerial reconnaissance revealed several areas understood to allow for adaptive ecological that appeared to be below their potential for management. There appears to be a reduction riparian vegetation. This calls for an in off-channel oxbow lakes for some distance understanding of the effect of dam releases on below the dam. There is need to explore the the diversity, extent and abundance of riparian feasibility of altering dam operations to facilitate vegetation. It is important to assess whether we natural rates of channel migration and evolution are losing riparian plant species due to dam and creation of complex river habitats. operations and explore the possibility of implementing a water release strategy that 2.2.10 Luangwa River Sediment provides for human needs and helps maintain deposition in the Luangwa River was an obvious riparian areas. observation during the field study. This is causing serious problems downstream as corroborated 2.2.7 Fisheries Resources Below Kariba Dam by Mozambican colleagues that highlight the The performance of river fisheries is correlated high turbidity experienced in the first basin of to the nutrient status of the habitat that is in Cahora Bassa Reservoir. It is therefore essential turn influenced by activities within the watershed to investigate the origin of the high suspended and discharges from upstream reservoirs where sediment load in the river. This could take the such exist (Lowe-McConnell, 1987). In the form of a study to track the sediment sources absence of historical data to allow for trends and their origins in order to distinguish between natural rates and human-caused drivers.

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opportunities to bring back fire to enhance 2.2.11 Luangwa River Fisheries wildlife habitat and other ecological processes? The local community pointed to a decline in 2.2.14 W a t e r fisheries Quality production and it © Michael L. McNamara is important to The principle water investigate the supply for many causes of the people in this area is perceived decline water drawn directly in the Luangwa from the river. What River fisheries. conservation There apparently measures can be is heavy fishing adopted to insure pressure all along adequate supplies of the lower section clean water for of the river communities? downstream from . 2.2.15 It is not clear Groundwater whether the There are many decline is due to communities served overfishing, by boreholes. habitat loss or However, the both. available groundwater supply, the rate of 2.2.12 Soil consumption and andWater Banana and horticulture farming along Zambezi River, Zambezi Heartland capacity to sustain this Conservation without significant It was observed that farms could benefit from draw down of water levels is not known, and simple cost-effective soil conservation practices. the impact of boreholes on local stream Many farmers are forced to abandon their land hydrology is also unknown. Use of water for after a few years due to low productivity. The irrigation could lead to other problems such as feasibility of applying soil and water conservation soil erosion or salt buildup (depending on water practices routinely in farming throughout the and soil chemistry) from flood irrigation. Zambezi Heartland needs to be explored. The area being cleared for cultivation is expanding 2.2.16 Springs, Ponds and Vernal Pools as more erosion-prone crops like cotton are During our aerial survey we observed numerous becoming popular in this semi-arid landscape. small ponds and springs, some in upland areas, This expansion needs to be mitigated. others in river valleys. Some apparently were permanent, and others filled in response to rains. 2.2.13 Fire It is essential to assess whether these ecologically There was little evidence of wildfires in the important areas need to receive special upland escarpment areas. What is the natural management emphasis and protection from fire regime in the Zambezi Heartland? What is human impact, and also check whether any the extent, severity and frequency of occurrence surveys been completed on these features. of fire in this landscape? What are the fire dependant species? How do fires influence runoff patterns and sediment supply? Are there

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2.2.17 Shifting Agriculture further investigated within key forest patches. This issue was of particular concern among the § Acacia floodplain: This habitat is largely Luangwa stakeholders, but was observed to be dominated by Faidherbia albida, an acacia common throughout the Heartland. species that is important as fodder for Diminishing productive capacity and erosion elephants and most large mammal during degradation of farms limit field use to a few years the dry winter seasons when all wildlife or less, with farmers moving on to available lands converges to the floodplain riverbank nearby. This leads to loss of sustainable for water. As such the habitat is under production capacity in the same fields, erosion intense stress as little regeneration and and subsequent water quality impacts, and recruitment seems to be occurring on the continued loss of native vegetation as new fields Zimbabwean side. Studies to understand and associated habitations are cleared. The the dynamics of this habitat need to be extent of this problem in the whole landscape initiated. still needs to be mapped and quantified in order § Wetlands: These encompass a variety of to develop targeted interventions. different ecological components e.g. Zambezi backwaters, pans and springs 2.2.18 Species and Habitats along the base of the escarpment, and In terms of biodiversity richness, the protected dambos in the headwaters of the Zambezi wildlife areas in the Heartland incorporate some tributaries. Survey work will more of the most outstanding terrestrial and riverine usefully be undertaken at the level of wildlife viewing and scenic landscape in management units rather than across the Southern Africa. The Heartland is typified by whole area. Immediate actions are to extended riverine habitat that hosts large assess the water hyacinth problem in the elephants herds (Loxodonta africana), backwaters of all rivers in the heartland; hippopotamus (Hippopotamus amphibius), also assess the biodiversity of fish in the crocodile (Crocodilus niloticus), lion (Panthera backwaters as these are unique habitats leo), leopard (Panthera pardus), buffalo (Syncerus and harbor the rare lungfish. Wetland caffer) a diversity of antelope, including kudu areas are also known to be highly (Tragelaphus strepsiceros), many smaller significant in terms of bird biodiversity mammals, reptiles and insects, and until very and there is need to identify key wetland recently, the black rhino (Diceros bicornis). areas from a birds’ perspective. There exists the potential for the endangered § Riparian woodlands: These are key black rhino to be relocated into its natural habitats both for wildlife and in terms of environment in this Heartland. The area also human settlement. Most areas have has an abundant avifauna with over 300 bird been strongly modified in the past. They species having been recorded. In addition, the support a number of plant, invertebrate Zambezi River is an important reservoir for and bird species of conservation interest freshwater fish resources that include the tiger or concern (and almost certainly other fish (Hydrocynus vittatus), lungfish (Protopterus taxa too such as herpetofauna and annextens), a wide variety of cichlid (tilapias) mammals). and cyprinid species, some of which are local § Escarpment/Gorge woodlands: endemics and rare species. Notable habitats Escarpment gorges provide a in this landscape include the following: microclimate with higher moisture status than surrounding areas. These areas are § Dry forests: These are unique and of known to support a number of plant continental significance. Dry forests are species that are absent from surrounding also known/suspected to support a areas, and are also known to be variety of animal species of conservation important in terms of bird populations interest, the status of which should be and small animals. Immediate action is

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to carry out a rapid aerial survey to the four ZIMOZA districts that have a total establish the occurrence and status of population of about 227,813 people. Within the such gorge woodlands along both the area, Guruve in Zimbabwe has the largest southern and northern escarpment areas. population and highest density while Zumbo District in Mozambique on the other hand is 3. Characterization, Existing Condition and sparsely populated. Discussion The border communities of the four districts The purpose of this step is to clarify the dominant share some historical background and culture physical, biological, and human processes or with the Chikunda being the predominant features of the watershed that affect ecosystem ethnic group. Nyanja is the predominant functions and condition. Characterization of the language of the border communities. Historical Zambezi Heartland was established through a and social ties are an important aspect of the series of activities ranging from field day to day lives of the border communities. A reconnaissance surveys, stakeholders workshops, significant number of border community compilation of secondary data, digital analysis members have some family ties across the of spatial data, and discussions with partners. border, either as family relatives or due to intermarriages. According to a survey Through these characterization efforts, the undertaken by ZERO, at least 15 % of the border assessment team has concluded that the overall community members declared that they had condition and function of watersheds in the relatives across the borders whom they visit Zambezi Heartland is good. Specifically, regularly (Marongwe, 2002). The civil wars in observations by the assessment team following Zimbabwe and Mozambique also contributed to field and aerial surveys, combined with the the family ties and intermarriages as people were previous work that has been done in the basin, displaced, some of them permanently, running led the team to suggest that the condition ranged away from the war. In this regard movements from fair to excellent, with an overall rating of across the borders are a common phenomenon good. Land conversion to farming, road as people visit their relatives. construction, and other land disturbing activities are still relatively limited. Watershed conditions Subsistence agriculture is the main source of were thought to be fair in areas affected by livelihood for the communities in this landscape. hydrograph and sediment alteration below Maize is the dominant crop. The main challenges Kariba Dam, the Luangwa Boma area, and parts to agriculture include, frequent droughts, lake of intensively farmed areas on the Zambian side of draught power, limited extension support of the Zambezi River below Kariba Dam. Most particularly as one gets closer to the border, high of the upland areas in all three countries, the cost of inputs and limited access to markets Luangwa river floodplain in most areas, much among other things. Despite these problems of the Zumbo and Magoe parts of Mozambique, reliance on subsistence cropping is high. and portions of the Lower Zambezi were in excellent condition. The trend in condition was Most of the border communities do not own thought to be stable, deteriorating or improving large livestock, cattle, due to past prevalence for many areas. However, future population of tsetse flies in the valley. Goats, however, seem pressure will determine trends since human use to be the most common livestock in the area as was the biggest driver for determining watershed they are owned, albeit in small numbers, by most condition. community members close to the border. Other forms of livestock are chicken and pigs. Pigs are 3.1 Human Uses particularly common in Zumbo district. The Zambezi Heartland has a population of The Zambezi and Luangwa rivers and their about 460,000, the majority of whom live in tributaries with abundant fish resources make

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fish an important source of livelihood, both as a by widespread influences on soil and water source of income and protein supplement. Apart resources. A lot of this negative impact is driven from the border communities of Guruve district, by anthropogenic interferences as local in Chapoto ward, who do not benefit a lot from communities and the private sector strive to fishing on the Zambezi River due to restrictive sustain livelihoods out of subsistence agriculture national regulations, fishing is an important and tourism development respectively. source of income for the communities in the other three districts of Luangwa, Magoe and However, wildlife habitats are still satisfactory, Zumbo. The communities from Luangwa seem mainly because a large proportion of the Zambezi to dominate the fish industry as they supply fish heartland is anchored around designated to their counterparts in Zumbo and Guruve protected areas, either parks or safari areas where districts and some have in fact pitched no settlement or uncontrolled development is semipermanent camps on the shores of the allowed. Threats exist in Game Management Zambezi and Luangwa rivers. Areas and open areas as human populations expand further into the otherwise uninhabited Tourism, both consumptive and non- game habitat. consumptive, is also increasingly, albeit quite slowly, becoming an important source of 3.3 Vegetation Cover employment for the communities in the trans- Overall, vegetative conditions appear to be good boundary landscape. The development of a in many observed areas of the Heartland. Most number of lodges along the Zambezi River on upland vegetation is still in natural form and the Zambian and Zimbabwean sides has resulted extent. Conversion to agricultural or domestic in a number of people getting employed. On uses is largely limited to a relatively small area the consumptive tourism side, the popular of the alluvial valleys and tributaries. Forest use community wildlife management programs, is limited to subsistence, or limited commercial, ADMADE in Luangwa, CAMPFIRE in Guruve utilization of trees for charcoal and building and Tchuma Tchato in Magoe and Zumbo, have material. resulted in significant income flows to the Detailed information on vegetation cover for the communities, most of which is invested in Zambezi Heartland potentially represents a data collective community projects and development gap. Parts of the Heartland have satellite initiatives. In fact tourism is viewed as one of imagery and interpretation. It is expected that the key potential for development in ZIMOZA more data is available from partners or may area. With sustainable utilization and proper already exist within AWF data systems. In marketing, fish seems to have an equally good general, the main vegetation types found in the potential. There is considerable dependence on Heartland include the following: non-timber forestry products largely in the form of wild fruits, charcoal and medicines. § Forest/shrub communities of deciduous dry savannah of Mopane and Miombo cover There has also been a recent trend towards uplands on the schist-gneiss-granitic rock commercial cotton farming in Guruve and landscape, and the mid and lower elevation extending into the Magoe district of correlating with the sandstone and Mozambique, a pattern that threatens habitat conglomerate rock type. The moderately integrity if left unchecked. deep to deep colluvial and deep to very deep alluvial soils supportriparian vegetation 3.2 Species and Habitats communities, including winterthorn, F. Wildlife and their habitats are of particular albida, with the riparian areas closest to water concern to AWF and this topic was given close sources supporting added species. Map 2 attention in this assessment. In general, wildlife below shows a general layout of the and their habitat are being negatively affected vegetation in the landscape.

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3.5 Geology The Heartland is bisected by the dominant central Zambezi River valley, an extensive ancient floodplain on Precambrian granite-gneiss complex overlain with sedimentary rocks (CIRAD- EMVT, 2000) The modern floodplain contains large areas of very deep Map 2: Showing broadly the original vegetation of the Zambezi Heartland (note that a lot of the areas have since been unconsolidated cultivated and this is not shown on the map.) alluvial sands and gravels. It extends to 40km wide in places with constrictions in the Kariba and 3.4 Erosion Processes Mupata gorges. The average altitude is 400m A primary concern in this watershed is the a.s.l. The southern area is a schist-gneiss-granitic impact that land use and management practices escarpment rising to 1,400m, sloping to the north are having on the Zambezi Heartland, and what and downward to the Zambezi. The Luangwa cumulative impacts expansion of land disturbing River is the other major drainage and another activity will have on ecosystem function and the dominant landform feature situated in the relation to wildlife habitat. The assessment team northeastern portion of the Zambezi Heartland. concurs with the notion that the existing and Its bedrock features appear similar to much of ongoing degradation of the basin’s soil resources the Zambezi with some potentially telling probably already has caused a significant decline differences in the uplands rock types yet to be in ecosystem productivity in some areas. This further examined. is evident in the ZIMOZA confluence area of the Zambezi and Luangwa rivers where the The dominance of bedrock of sandstones (Karoo, downstream Mozambican side is affected by silt Forest, Dande) and crystalline schist-gneiss- from upstream and the production of the granitic, also referred to as Pre-Cambrian freshwater sardine, Limnothrissa miodon formations is an overriding influence on the (kapenta) in Cahora Bassa reservoir is believed character of the entire Heartland area. to be negatively affected by the resultant high turbidity. The higher portions (elevations) of the area (Highlands) appear to be schist-gneiss-granitic Soil and geological resources drive or affect all inter-bedded with quartz veins. While some the terrestrial and aquatic ecosystem processes layers of metamorphic schist are quite hard and of the basin. To a large extent productivity, durable, much of the remainder of the complex precipitation storage and release, and landscape shows considerable weathering at the surface biodiversity, in conjunction with climate, are soil producing sands and gravels. These materials dependant. appear to be produced throughout the extensive dry season and begin movement through dry

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ravel processes. Rainfall comes typically in rather from the sandstone, conglomerate and the schist- intense thunderstorms with sufficient energy to gneiss-granitic formations affects both the nature move large volumes of these loose, incohesive of the riverine environment and the productive sand and gravels. capacity and stability of the soils. The runoff from the intense rainfall is rapid, carrying all the Below these rock types in elevation is a accumulated material, including vegetative, off- conglomerate unit of limited extent with mixed site, downhill and downstream. All soils exhibit composition that appears to include some softer high erosion potential and erode readily in the and finer component of siltstone and cemented absence of stabilizing vegetation. Sheet, rill and alluvial coarse fragments typically of large gravel, gully, and streambank calving all are occurring cobble and small stone. in areas without adequate ground cover and root mass. Long dry periods allow accumulation of The lower portions of the drainage - right to soil particles from dry ravel and desiccated plant rivers edge in places- consists of the sedimentary material. Intense rainfall then moves this sandstone formations. These appear to be collection of material downslope, suspending the moderately competent but with high rates of finer grains (fine sands and smaller generally) decomposition producing large amounts of sand, into the watercourses. gravel, and cobble. The hyperthermic (continually high with little The extensive floodplain areas and drainages of variation) temperature regime produces rapid the various tributaries are composed of largely decomposition of organic matter, as is typical of non-cohesive sand deposits with varying tropical regions, making the retention of these amounts of finer and coarser material at depth. materials all the more critical. This is true both The movement and dynamics of these materials for sustained agricultural production or is discussed in the hydrology section. reestablishment of native vegetation where areas have been degraded due to abandonment of The upper reaches of the Luangwa River system crop fields or other highly disturbed areas from appear to have some fairly extensive areas of concentrated animal or human activity. conglomerate, including shale and siltstone (Geology of Zambia, 1997) that may account Upland areas on ridges and upper sideslope (at least in part) for the larger, finer sediment positions consist of bedrock and shallow residual load in the Luangwa as compared to the soils derived from the parent rock. They are Zambezi. loamy, with textures ranging from loam to loamy sand with high coarse fragment content both in The overall geomorphic character is one of a the surface and within the soil profile. The lower highly dynamic environment producing large sideslopes and footslope positions consist of amounts of non-cohesive sediments, primarily moderately deep colluvial soils from the of fine to coarse sands with some gravel and adjoining bedrock. There is little evidence of cobble sized coarse fragments moving within the other parent materials from wind-derived delivery system (downslope and to rivers and sources, although there is one mention of aeolian streams). The extent of added sediment loads parent materials in one reference (CIRAD, to this already high sediment load system is 2001). unknown, but appears to be relatively small in relation to the overall natural condition. The fluvial drainages have deep deposits of this material with varying levels of soil development. 3.6 Soils Most soils appear to be relatively young and minimally developed due to the dynamic nature Soil characteristics are a direct reflection of the of the environment. Those materials that have rock types, vegetation and climatic factors in been in place for sufficient time have weathered the area. The predominance of sandy material

14 Zambezi Heartland Watershed Assessment

out some available minerals allowing for animal trails was observable with many increased fertility. coinciding with the active erosion. The few roads along the main Zambezi showed signs of erosion The long dry periods must limit the activity of with rills and gully formation both on the road microbial populations and weathering processes surface and adjacent berm, although most roads that occur in more consistently moist did not appear constructed. environments elsewhere in tropical or subtropical temperature regimes. This should High banks of dominantly sandy material are reduce the rate of leaching of available nutrients calving off large amounts of sediment directly in the areas that are stable and level enough to into both the Zambezi and Luangwa during high allow for infiltration through the soil profile. water periods. This has a direct effect on water quality but appears to be largely reflective of Land Use Implications natural conditions within these drainages given the geomorphic and climatic character. In areas These soils, while better than much of the where streambank farming occurs adjacent to surrounding uplands, still cannot provide macro these unstable, productive capacity is obviously or micronutrients in adequate amounts for lost with the material. sustained production of high demand crops such as hybrid corn (maize). Nitrogen cycling back 3.7 Hydrology into the rooting zone is needed to maintain native vegetation. Conversion to agricultural Limited data exists on the surface water production requires retention and recycling of hydrology of streams and rivers in the Zambezi plant materials, and amendments in organic or Heartland in terms of the amount of streamflow inorganic forms, to support any sustained crop and it’s flow magnitude, frequency, and duration. production, but especially in corn rotations. Further, there is little information on an assortment of water quality impacts to tributaries Some crop production was observed on upland and the mainstream Zambezi, and the lack of sideslopes, particularly along the Luangwa. These this information represents a major data gap. fields had cobbly, very gravelly sandy loam There are many tributaries to the Zambezi that surfaces which showed evidence of overland flow have little or no information on hydrology, rates and active erosion. It was indicated to us by the of natural and human-caused sediment local farmer and fisheries representative production, or water quality. Information does providing our transportation that these fields exist on the flows below and above Kariba Dam. typically only last a few years before they must This data could be used to help with evaluation be abandoned. The farmer indicated he had of post-dam hydrologic and channel impacts. been working this field for four years. Active More information is needed on precipitation clearing of adjacent forest (again on steep amount, distribution, duration and intensity in sideslopes) was occurring along the margins of the Heartland, although some precipitation the fields. These slopes and soils are too steep gauges do exist. Information on the abundance, for any sustainable agricultural production and extent, quality, and recharge rates of would be best left in native forest cover. groundwater are not available for many areas in the Heartland. Areas of the Zambezi River floodplain terraces are exhibiting erosion of the terraces with Surface Water Hydrology gullying evident from the air. This was most There is a dense network of seasonal and prevalent in the Parks and Safari areas on the perennial channels throughout the Heartland Zimbabwe side. It appears that this may be upland areas. Outside of settlement areas or correlated to animal concentrations, particularly transportation corridors such as major roads and of elephants, as this was not common in other rivers with some exceptions these streams observed areas. A rather extensive network of appeared to be in good condition as viewed

15 Zambezi Heartland Watershed Assessment

during the aerial survey. A stream in good disturbance and sediment supply, disturb condition simply stated is one that does not show riparian vegetation extent, abundance, and significant signs of channel instability, does not recruitment, and can change runoff patterns and appear to have significant water quality impacts, the safe storage and release of surface flows. Safe has well developed riparian vegetation, and does storage and release of water simply stated means not appear to be altered by human activities. that vegetation and ground cover is adequate Many of the smaller streams and rivers appeared to allow for rainfall infiltration, and slows to flow only in response to large storm events, overland flow protecting soils from erosion. and large storms appeared to be quite common Runoff, once it is allowed to infiltrate, can be during the rainy season. Seasonal channels more slowly metered to streams or groundwater. reflected strong peak flows, and only sustained Most human impacts within the Heartland flow for short periods. Smaller perennial consisted of roads, subsistence farms, cleared channels sustained flow during the wet season, areas for dwellings, and localized streambank and showed signs of active large flooding in many disturbance from gathering reeds or collecting areas. During the dry season, these channels water. Abandoned farms were also a major tend to dry to the point where only pools of impact, since from field surveys they appeared varying depth exist. to be slow to recover ground cover and are prone to gullying and other erosion. These soil Stream instability along the Rufunsa and disturbances often lead to erosive surface flow, Luangwa Rivers caused by streambank farming and with no ground cover runoff tends to be was observed in several localities. Streambank more erosive, and floods tend to be higher in farms strip soil of their protective cover of magnitude and more damaging, especially in streambank adapted riparian vegetation. These areas of extensive ground disturbance. types of trees, shrubs, grasses and reeds are adapted to the streamflow regime of the channel, Wetlands, Springs and Ponds and when in good condition hold streambanks Significant wetland areas were observed in the together through dense fibrous root systems. Heartland, mainly along the Zambezi River Streambank farming destroys this vegetation, channel in the form of abandoned and replaces it with a large percentage of bare which appear to be oxbow lakes that have filled soil, and cultivated plant species that do not in with vegetation. Some of these may be provide adequate root strength to hold riparian seasonal, and some perennial, and to a large soils together during floods and rainstorms. A degree the degree and seasonality of these wet remarkable example of this was observed near areas depends on river water levels. Additional Luangwa Boma, where a several hundreds meter surveys are needed to determine the extent of section of streambank had been converted to wetland resources along the Zambezi River. maize. Consequently, the stream is actively These near-river wetlands are important for a eroding the bank, widening the channel variety of important functions, including cycling significantly, and redepositing rich riparian soils of nutrients and providing essential habitat and downstream. A similar occurrence was observed forage areas for a variety of species. Large floods along a section of the Rufunsa River, where a that caused the river to shift patterns school was threatened by an actively eroding periodically before the building of Kariba Dam farmed streambank. The opposite side of the probably helped create conditions along the river river in contrast was not farmed, had intact corridor where these wetland areas could get riparian vegetation, and showed no sign of established. instability or erosion. In the aerial survey, numerous ponds were Human Impacts to Stream Channels observed away from the river corridor, and many Human impacts to stream channels of these were seasonal in nature. Some of these corresponded to settlement patterns, primarily ponds were located in upland areas far from the since settled areas cause increased soil river. These seasonal ponds are typically called

16 Zambezi Heartland Watershed Assessment

vernal pools, and are extremely important sediment from side drainages, sand bars were ecologically. Perennial more actively being

ponds fed by springs © Michael L. McNamara deposited. were also observed. A more detailed In the aerial survey, the inventory of the river channel appeared location and quality of to be slightly degraded perennial and seasonal or entrenched, and ponds and springs is river terraces showed needed. signs of severe gullying in many places. Impacts of Kariba Dam Entrenchment or In designing flows degradation is generally below major dams, in defined as a lowering of order to preserve the the rivers’ base level, ecology of the river thereby disconnecting landscape it is it from former necessary to consider floodplain, and the ecological impact reducing the extent of of different flow the flood-prone area regimes. Table 1 (Rosgen, 1998). Most displays the ecological of these gully networks functions of different drained back to the river flows for a typical river Gully networks along Zambezi River, Zambezi Heartland River. The gullies in many (Postel and Richter, 2003). areas were in locations The functions of low-flows, higher flows, and undisturbed by human uses. It is unclear why large floods all play key roles in the ecology of these gullies were forming in the river terraces, the river, and the adjacent floodplain. These but we speculate that a combination of animal ecological functions have been documented in use concentrated in the riparian area, lack of numerous scientific papers in recent years. substantial understorey vegetation, and fragile soils led to gully formation. The Zambezi River Corridor appears to be impacted by flow and sediment changes below There may be a connection to dam operation, Kariba Dam. The channel appeared to be stable, as often below dams channels become with little sign of recent channel migration, and entrenched or degraded due to decreased sand bars stabilized with riparian vegetation, for sediment supply and changes in flow regimes. over 40 miles below the dam, with effects of the Formulas for entrenchment utilize concepts of dam probably extending to some degree all the bankfull flow for field delineation, however the way to Lake Cahora Bassa. Old meander scrolls concept of a bankfull flow is not relevant for appeared devoid of vegetation, and there were flow releases below dams, so it is difficult to scant oxbow lakes, or off-channel ponds formed exactly quantify the degree of entrenchment. from former river meanders. There were few However, generally, degraded or entrenched actively forming or redeposited sand bars in this conditions may have led to dewatering of soils locale. Sand bars can be important for rivers in adjacent to the river, or reduced the extent of that newly deposited bars are often sites for areas that were once inundated periodically by establishment of the first stage of new riparian floods. This in turn can reduce the abundance vegetation communities that are important for and extent of riparian plant species, and wildlife species, and may provide other values. combined with heavy animal use, can increase Farther downstream, as the river recruited more bare soil leading to a higher potential for soil erosion and gullying, as we observed.

17 Zambezi Heartland Watershed Assessment

Table 1: Ecological Functions of Different Flows Before Kariba Dam, large floods were common along this section of the Zambezi. Flow Level Ecological Roles Understandably, the dam apparently has altered Low (base) flows § Provide adequate habitat space for aquatic organisms flood timing, magnitude and frequency to a large § Maintain suitable water temperatures, dissolved oxygen, and water extent. Floods are important for large rivers. chemistry During floods, fish and other mobile river § Maintain water table levels in floodplain, soil moisture for plants § Provide drinking water fro terrestrial animals organisms are able to move upstream, or out § Keep fish and amphibian eggs suspended onto or flooded wetlands, accessing § Enable fish to move to feeding and spawning areas additional habitat, and these habitats can § Support hyporheic organisms (living in saturated sediments) provide additional food sources and spawning Drought level areas for fish (Postel and Richter, 2003). Large § Enable recruitment of certain floodplain plants floods have been found to influence the extent § Purge invasive, introduced species from aquatic and riparian and types of riparian vegetation, and some communities species have been found to be dependant on § Concentrate prey into limited areas to benefit predators floods for regeneration. The extent to which Higher flows § Shape physical character of river channel including pools and riffles the flood regime changed the riparian vegetation § Determine size of streambed substrates § Prevent riparian vegetation from encroaching into channel below the dam has not been assessed. Because § Restore normal water quality conditions after prolonged low flows, of this importance for fish and their habitats, flushing away waste products and pollutants flood restoration below African dams has been § Aerate eggs in spawning gravels, prevent siltation attempted for the Logone River in Cameroon, § Maintain suitable salinity conditions in estuaries the Hadejia in Nigeria, and the Phongolo River in South Africa. Large floods § Provide migration and spawning cues for fish § Trigger new phase in life cycle (e.g. insects) Ecologists in South Africa in particular have § Enable fish to spawn on floodplain, provide nursery area for established some general principles for juvenile fish protecting flows adequate to maintain river § Provide new feeding opportunities for fish and waterfowl § Recharge floodplain water table health (Tharme and King, 1998) called the § Maintain diversity in floodplain forest types through prolonged “Building Block Methodology.” This method inundation (i.e. different plant species have different tolerances) attempts to define the river flows needed for a § Control distribution and abundance of plants on floodplain river to protect or restore desired biological, § Deposit nutrients on the floodplain physical habitat, and water quality features of § Maintain balance of species in riparian and aquatic communities the ecosystem while allowing for human uses of § Create sites for recruitment of colonizing plants water. A central theme of any flow restoration § Shape physical habitats of floodplain strategy is that the dam flow releases attempt to § Deposit gravels and cobbles in spawning areas use the natural flow regime as a guide or § Flush organic material (food) and woody debris (habitat structures) reference. into channel § Purge invasive, introduced species from riparian and aquatic communities Low-flows are also ecologically important § Disperse seeds and fruit of riparian plants components of flow regimes. It is the dominant § Drive lateral movements of river channel, forming new habitats flow regime of most rivers, and determines the (secondary channels, oxbow lakes) amount of habitat available for most of the year, § Provide plant seedlings with prolonged access to soil moisture and it has a strong influence on the number and diversity of fish and other aquatic organisms that can live in the river. There is need to document how Kariba Dam changed low flows for the Zambezi River and how well the low flow conditions resemble natural pre-dam conditions.

18 Zambezi Heartland Watershed Assessment

Groundwater Resources and peripheral status such that minimal There are numerous developments ever perennial or seasonal took place. This springs and ponds in the © Michael L. McNamara obviously rendered Heartland. The field the wildlands pristine survey did not cover and provided much ground and this conducive habitats for aspect requires detailed wildlife. Forty-five assessment in order to years ago, Lake have reliable baseline Kariba was information. nonexistent and the flow regime of the Meteorology Zambezi River Precipitation for the followed a natural Heartland reflects a pattern, and use of the tropical dry climate with riverfront by the two clearly defined native inhabitants was seasons: a rainy season for alluvial crop from mid-November to cultivation for mid-March, and a dry subsistence purposes season the other only. There were no months, usually from tourism June to October. developments as you Average annual Upland watershed conditions, Zambezi Heartland see them today on the temperatures typically river frontage. are about 250C. October and November, which directly precede Over the years during the post-colonial era, core the rainy season, are the hottest months with settlement centers like Kariba, Chirundu, maximum temperatures over 400C, while June Luangwa Boma among others were established. and July sometimes have lower temperatures with The creation of reservoirs for power generation lows sometime reaching 100C. (at Kariba, Kafue and Cahora Bassa) brought their own modifications to the ecological flows. Rainfall amounts for much of the lower elevation Designation of protected areas meant better areas in the Zambezi and Luangwa Valleys ranges protection to wildlife resources, but associated from 350-500 mm annually, and the higher with the attendant carrying capacity problems elevation areas annual rainfall typically ranges in sites where distribution is uneven and from 450-650 mm. This area is prone to localized degradation takes place. receiving high amounts of precipitation in very short periods, and this can lead to substantial The subsequent effective tsetse fly control erosion and stream flooding. There was programs in the valley opened up more areas in considerable evidence of this throughout field the landscape for human settlement. This has visits in the Heartland. resulted in the current status as discussed earlier. It will be valuable to collate information from secondary sources on the land use patterns and 4. Reference Conditions natural resource base status and then build a It is noteworthy most of the area under the scenario that capture what was (i.e. the reference Zambezi Heartland was in the past uninhabited condition), what is (current status) and what will due to inhospitable climatic conditions and tsetse be (the future). fly infestation. The threat of sleeping sickness, livestock disease relegated the area to a marginal

19 Zambezi Heartland Watershed Assessment

Changes to soil and water resources and land floodplain agriculture expansion and use impacts as compared to pre-settlement development along perennial and seasonal conditions on an area basis are measurable by tributaries and the main-stem Zambezi River, the amount of conversion of native vegetation effect of a loss of floodplain function and riparian to cropland, settlements, and road construction. vegetation from dam-regulated flows in the Statistics for these categories can be tallied to Zambezi River below Kariba Dam, and observed the extent they are available. The magnitude of soil erosion and gullying along the Zambezi the impacts to water quality from land River. Another concern is the uncertainty disturbance is more difficult to measure. The regarding the combined effects of safari lodges previous discussion lends considerable insight to and other development on water quality and changes in the watershed from comparatively stream morphology along the Zambezi River. recent changes as human expansion has occurred within the last 50 years, in particular. Specific recommendations for management of the Zambezi Heartland are: 5. Summary and Recommendations · Formulate land use plans - There is a lack The aim of AWF at this stage is to utilize the of coordination in the Heartland regarding findings of this assessment to formulate many aspects of natural resource management recommendations that can be management. Land use plans, perhaps implemented with partners and stakeholders coordinated on a District basis, are badly working in this ecosystem. AWF will look for needed in order to guide future ways to work close with institutions such as development. Zambezi River Authority, and institutions in ZIMOZA that are already developing the means · Evaluate land carrying capacity for humans to implement management actions that have and wildlife - The carrying capacity of land emerged from previous assessments. AWF will resources to support increasing human also continue compiling and synthesizing population and wildlife populations in the information that already exists and add to it three countries needs to be studied where possible, specifically through increased extensively and a comprehensive plan GIS data synthesis and through setting up a developed that addresses these impacts. monitoring program in targeted areas of the This is an urgent need due to the relatively Heartland. low human population densities in the Heartland and the anticipation of future A primary concern that was observed and growth. validated by stakeholder groups in several watersheds in the assessment area is the impact · Riparian and floodplain conservation plans land use practices are having on river and stream - There needs to be a reasonably consistent systems in the Zambezi Heartland. AWF and conservation plan for floodplain and the USFS hosted three stakeholders workshops riparian management for the major drainages to gather information from stakeholders who are across the Heartland. This plan would living in the Zambezi Heartland to help provide guidelines for floodplain understand the issues and key questions affecting development, floodplain farming, and land management and human use. The provide management objectives for gathering of partners and stakeholders to discuss preserving sustainable human uses and the the assessment was useful for hearing from local ecology of these important areas. land managers and validating ecological assessment efforts. One of the main focuses of · Kariba Dam flow releases and floodplain the workshop was to identify and agree on the ecology - Dam releases for the Zambezi River issues and key questions that are affecting the need to be coordinated to provide the best Zambezi Heartland. Of particular concern is the possible ecological benefit for floodplain

20 Zambezi Heartland Watershed Assessment

plant communities, to provide favorable strategies, and the use of controlled or stream geomorphology and floodplain uncontrolled fire to achieve ecological habitat value, to reduce erosion processes, objectives. This strategy would attempt to for the benefit of all plant and animal species. reduce impacts on soil erosion and water Riparian vegetation needs to be studied to budgets to ecologically sustainable levels. understand the relationships between flow regimes and the recruitment of ecologically · Zambezi River lodges and developments - desirable species. Develop a strategy to monitor the effects of sewage releases from developments along the · ZIMOZA Water resources management Zambezi River, and develop a policy to strategy - A coordinated comprehensive regulate sewage outflow into the River for water resources management strategy present and future operations. regarding water rights and uses needs to be developed between interest groups along the · Enforcement of conservation laws - There Zambezi and Luangwa Rivers. This strategy is a lack of enforcement of conservation laws should identify water needs for human use, in some areas of the Heartland such as those and provide effective ways to provide for laws regulating streambank farming, forest river ecological health and human health as harvest cutting, and wildlife poaching. much as possible. It needs to take into account political differences between the · Crop rotation - The application of three countries, and policies of different appropriate alternate cropping systems or districts and other authorities. rotations and species, including nitrogen- fixing legumes or similar plant groups, would · Streambank farming impacts and sediment be very advantageous. Some form of production - Determine effects of composting of crop and animal refuse may streambank farming on soils and water be possible for reuse on fields and gardens. budgets and using that information establish It is essential to take on board best practices policies in the three Heartland countries to from research into this going on in southern manage the in-migration of people into the Africa or other regions with similar climatic Heartland to build ecologically sustainable regimes. communities and farming practices that accommodate the ecological and human · Value-added products - Continued needs of this area. emphasis on value-added products from forest tree species, in conjunction with · Soil and water conservation practices - reforestation practices, would provide added Develop suitable soil and water conservation economic potential while maintaining native strategies for subsistence and commercial forest plant communities. agriculture for reducing soil loss and erosion. Environmental education of locals and DATA GAPS - Core topics needing more sharing of successful techniques is essential. information or compilation of existing This could be framed in the manner of soil information include: and water conservation districts utilizing the existing Extension organization and various 1. Kariba Dam: pre and post Dam hydrology Resource ministries (e.g. Forestry, comparison; Hydrographs from ZRA. Agriculture). 2. Additional geologic information- Geologic · Wildfire and controlled fire - Establish maps. consistent wildfire control and management strategies for all Heartland countries. This 3. Soil maps and characterization including any policy would address wildfire suppression laboratory analysis.

21 Zambezi Heartland Watershed Assessment

4. Precipitation map 6. References 5. More detailed information on settlement patterns on river and stream corridors and Cirad-EMVT, 2001. The Mankind and the Animal uplands; maps with detailed settlement areas, in the Mid Zambezi Valley, Zimbabwe, 76 pages. and resource surveys to validate assumptions regarding impacts; and explore ways to develop Lowe-McConnell, R. H., 1987. Ecological studies a predictive model for determining future in tropical fish communities, 382p. settlement patterns. Mavi, S., et al. 1997. Analysis and Diagnosis of 6. Determine best flows for fish habitat and the State and Use of Flora of the Mid-Zambezi Valley, breeding success in Zambezi River. Components Biodiversity Conservation Project, Harare, 25p. of this could be: § Determining the preferred combination Nyamapfene, K. 1991. The Soils of Zimbabwe. of depth and flow velocity and cover for Nehanda Publishers, 179 p. main fish species. § Understanding the life history of the Poilecot, P. 1996. Natural Resources in Southern various fish species including preferred Africa: an Overview of Potential and Threats. habitat at different life stages. RTTCP/CIRAD, Harare, 72p. § Conducting surveys of existing habitat and provide estimate of potential habitat Postel, Sandra and Brian Richter. Rivers for life, Managing Water for People and Nature, 2003. 7. Information on flows that would provide Island Press, 253 pages. better riparian habitat and recruitment of riparian plant species; studies for understanding Rosgen, D.L. 1996. Applied River Morphology, the recruitment and regeneration of riparian Printed Media Companies, Minneapolis, dependent species like winterthorn, F. albida.; Minnesota. and the magnitude and duration and frequency of flooding required and timing to be Tharme, Rebecca E., and Jackie M. King, 1998. determined, and factored into how the existing Development of the building block methodology for dam operations affect key riparian species and instream flow assessments and supporting research other plant communities. on the effects of different magnitude flows on riverine ecosystems. Cape Town, South Africa: Water 8. Survey of riparian plant species along the Research Commission, 1998. Zambezi River and indication of their relative health. Timberlake et al. 1993. Vegetation Survey of the Communal Lands- North and West of Zimbabwe. 9. Studies on development of Kirkia, 14(2). 171-270. opportunities for providing for water sources for agriculture.

10. Information on extent, quality and quantity of groundwater from valley floor and upland aquifers for community, crops and livestock.

10. Inventory of springs and vernal pools for spatial density and distribution of sources for wildlife and humans.

22 This Pub- licationThis Pub- islication funded byis fundedthe Nether-by the landsNether- Ministrylands ofMinistry For- eignof For- Af- fairs/Di-eign Af- rectoratefairs/Di- Generalrectorate African Wildlife Foundation forGeneral Inter- Zambezi Heartland for Inter- P.O. Box 179 national Kariba Coopera-national Zimbabwe tionCoopera- Email: [email protected] (DGIS).tion (DGIS).

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