Potential for payments for watershed services and climate change adaptation in Pangani river basin, Tanzania

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Universiteit Antwerpen


Watershed ecosystems deliver multiple watershed services which are crucial for human well-being, the society and the economy. They also perform key ecological functions essential for water quality and quantity. Nevertheless, they have been degraded. For many years, the actual value of watershed services has been neglected, underestimated and not factored in land use decisions for sustainable management strategies. The problem is vividly experienced in developing countries which are characterized by: (i) lack of sufficient number of skilled manpower to spearhead conservation activities; (ii) limited budget for financing conservation programmes; (iii) escalating human population which overwhelm the capacity of watersheds to provide watershed services; and (iv) climate change and climate variability which aggravate the situation of water scarcity. In response to these problems, conventional conservation e.g. creation of protected areas (by fencing or fining encroachers) and participatory approaches (e.g. joint natural resources management approaches) were initiated. Unfortunately, they have so far failed to yield the desired outcomes. In recent years market-based approaches have been recommended as paradigm shift towards watershed conservation for sustainable flow of watershed services. This thesis reports findings of a research carried as an attempt to develop a concept for Payments for Watershed Services (PWS) Scheme to conserve watershed ecosystems for sustainable flow of watershed services along the Pangani River Basin (PRB) in Tanzania. Specific objectives include: identification of ecosystem goods and services delivered by watersheds; determination of government involvement in financing conservation; analyzing the effects of water grabbing and foreign direct investments on the delivery of watershed services; assessing watershed dynamics and irrigated agriculture as adaptation option to water shortages, climate change and climate variability; analyzing policy constraints in water and watershed governance; and investigating drivers for respondent’s willingness to pay (WTP) and the marginal effects for willing or unwilling to pay for watershed conservation. Results shows that the PRB delivers four categories of ecosystem (watershed) services. They includes: provisioning services (such as paddy, maize and natural foods from the forest); regulating (i.e. water flow, air purification and climate xvii modification); supporting (e.g. soil erosion and nutrient cycling); and cultural (scenic beauty and recreation). Water is used for irrigated agriculture (maize and paddy), production of hydroelectric power (i.e. electricity) at Nymba ya Mungu Dam, Pangani and Hale power plants, and enhance nutrient cycling and ecological processes at Kirua Swamp. However, conservation of watersheds along the PRB is constrained by lack of commitment and financial support from government institutions. For instance, findings from this study indicate that the budgets for financing conservation activities was €159490, 62 and €329665, 85 for the 2004/05 and 2008/09 financial years, respectively. Nevertheless, only €82693, 72 and €234537, 77 were allocated to conservation activities for the 2004/05 and 2008/09 financial years, respectively. This testifies the lack of enthusiasm and interest on watershed conservation. In addition, water officers responsible for water distribution, allocation and rationing facilitate illegal water abstraction thereby accelerating water grabbing malpractices. Results on the effects of water grabbing indicate that the mean yields before water grabbing is higher than yields after water grabbing. Responses from the respondents indicate that local drivers for water grabbing include poor water governance, corruption and lack of transparency. Global drivers for water grabbing include climate change and climate variability, population growth, change of consumption patterns and global economic growth. Enforcement and implementation of clauses stipulated in the Land policy, Land use Act and the Village Land Act about sustainable land uses would bring about a winwin situation between investors and smallholder farmers. Furthermore, transparency in land acquisition; promoting investments that ensure smallholder farmer’s social security, ground water research, and rainwater harvesting would restore the former situation. Watersheds along the PRB have undergone changes caused climate variability and population increase. Findings from human population census indicate an increase of trend of population which exerts pressure on water demands. Smallholder farmers xviii adapt to water shortages through water rationing, irrigating during the night, using short term seed varieties and drought resistant crops. Results on rainfall variability indicate a positive and statistical significant (p < 0.05) influence on water flow. This implies that one m3 rainfall influences the increase of water flow at the magnitude of 0.466 m3s-1. Due to climate variability and rainfall fluctuation, the government through the Ministry of Agriculture, Food Security and Cooperatives should encourage and support smallholder farmers to carry out irrigatition as adaptation option to the failure of rainfed agriculture. With regards to conservation, a holistic approach for watershed conservation is recommended for the attainment of long-term objectives along the PRB. Nevertheless, sustainable watershed conservation and long term conservation objectives require a sound policy framework supporting water and watershed governance. It was revealed that watershed conservation and water governance along the PRB are constrained by policy failures and lack of commitment among leaders to enforce laws, regulations and by-laws. Lack of accountability coupled with corruption is also reported as the catalysts for watershed degradation. Uncoordinated water governing institutional structures and untrustworthy financial management sums up watershed conservation problems. Building the capacity of water users association would bring about positive outcomes for both watershed conservation and water governance. Measures aimed at improving water flow should also focus on strategies for improving the welfare of the smallholder farmers and their willingness to participate fully in conservation programmes. Results from the probit model on drivers for respondent’s WTP for watershed conservation show that marital status, household size and distance from the water source positively influenced small scale farmers’ WTP. Moreover, occupation, income from irrigation, and amount paid for irrigation influence negatively small scale farmers’ WTP. The result also reveal that education level, total land size and yield with irrigation influence positively on the amount that respondents are WTP. Overall, results from regression model indicate a positive influence (p < 0.001) on the amount that respondents are WTP. The goodness fit of the model (0.62) explain 62% xix variation of the variables included. The rest i.e. 38% could be explained by external factors. Although these statistical analyses are in favour of PWS scheme, limitations, weaknesses and criticisms identified in Chapter 1 in Subsection 1.4 necessitates further research before its implementation.




Pangani, Tanzania, Climate change adaptation, Watershed services