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Technical Manual no. 5

Rainwater harvesting innovations in response to water scarcity

The Lare experience

Hydrologic impacts of ponds on land cover change

Runoff water harvesting in Lare, Kenya

RELMA Technical Report (TR) series

Rainwater harvesting by a Maasai Community: An evaluation report on a project in Talek of Masai-Mara, Kenya.Tanguy de Buck, Maimbo M. Malesu, Bancy Mati & Alex R. Oduor. TR No. 31. ISBN 92-9059-190-0

Impact of Rainwater Harvesting: A case study of rainwater harvesting for domestic, livestock, environmental and agricultural use in KusaOrodi J. Odhiambo, Alex R. Oduor & Maimbo M. Malesu. TR No. 30. ISBN 92-9059-180-3.

Empowering rural communities: Rainwater harvesting by women groups in Rakai, Uganda. Julianne Rugasira, Millie Abaru and Rolf Winberg. TR No. 29. ISBN 9966-896-47-3.

Low-cost methods of rainwater storage: results from field trials in Ethiopia and KenyaHune Nega and Paul M. Kimeu. TR No. 28. ISBN 9966-896-64-3

Farmers’ initiatives in land husbandry: promising technologies for the drier areas of East AfricaKithinji Mutunga and Will Critchley with P. Lameck, A. Lwakuba and C. Mburu. TR No. 27. ISBN 9966-896-63-5

Marketing of smallholder produce: a synthesis of case studies in the highlands of central KenyaStachys N. Muturi (ed.), Julius K. Kilungo, Kavoi M. Muendo, Zacharia Mairura and Joseph G. Kariuki. 2001. TR No. 26. ISBN 9966-896-56-2

Agricultural education in Kenya and Tanzania (1968–1998)David Ngugi, Aida Isinika, August Temu and Aichi Kitalyi. 2002. TR No. 25. ISBN 9966-896-58-9

Estimating costs and benefits on crop production: a simplified guide for smallholder farmers in EthiopiaTakele Zegeye, Abdurahim Ali, Admasu Kebede, Katarina Renström and Gedion Shone. 2000. TR No. 24. ISBN 9966-896-50-3

Soil conservation in Eritrea: some case studiesAmanuel Negassi, Bo Tegngäs, Estifanos Bein and Kifle Gebru. 2000. TR No. 23. ISBN 9966-896-43-0

We work together: land rehabilitation and household dynamics in Chepareria Division, West Pokot District, KenyaWilliam Makokha, Samwel Lonyakou, Monicah Nyang, K.K. Kareko, Christine Holding, Jesse T. Njoka and Aichi Kitalyi. 1999. TR No. 22. ISBN 9966-896-42-2

Agroforestry extension manuals: a survey of their use in KenyaStachys N. Muturi. 1999. TR No. 21. ISBN 9966-896-41-1

Traditions and innovation in land husbandry: building on local knowledge in Kabale, UgandaWill Critchley, Dan Miiro, Jim Ellis-Jones, Stephen Briggs and Joy Tumuhairwe. 1999. TR No. 20. ISBN 9966-896-38-4

Evolution of provision of tree seed in extension programmes: case studies from Kenya and UgandaChristine Holding and William Omondi (eds). 1998. TR No. 19. ISBN 9966-896-34-1

Participatory planning and implementation: experiences with farmers from Nyandarua District, Kenya, 1992–1995Christine Holding and Kiunga Kareko. 1997. TR No. 18. ISBN 9966-896-30-9

Parks and people—conservation and livelihoods at the crossroads: four case historiesJonas R. Kamugisha, Z.A. Ogutu and Michael Ståhl. 1997. TR No. 17. ISBN 9966-896-29-5

Land husbandry education in agricultural colleges of eastern Africa: an overviewTesfaye Abebe. 1997. TR No. 16. ISBN 9966-896-28-7

Zero grazing, an alternative system for livestock production in the rehabilitated areas of Kondoa, TanzaniaTekie Gebregziebher, A.P. Masaoa, C.M. Shayo, H.A. Ulotu and E.J.M. Shirima. 1996. TR No. 15. ISBN 9966-896-27-9

Twenty years of soil conservation in Ethiopia: a personal overviewBerhe Wolde-Aregay. 1996. TR No. 14. ISBN 9966-896-26-0

Changing environments: research on man–land interrelations in semi-arid TanzaniaCarl Christiansson and Idris S. Kikula (eds). 1996. TR No. 13. ISBN 9966-896-25-2

The hand of man: soil conservation in Kondoa eroded area, TanzaniaCarl Christiansson, Alfred C. Mbegu and Anders Yrgård. 1993. TR No. 12. ISBN 9966-896-18-X

Management of natural resources and environment in Uganda: policy and legislation landmarks, 1890–1990Jones R. Kamugisha. 1993. TR No. 11. ISBN 9966-896-17-1

Environmental education: experiences and suggestionsValdy Lindhe, Miles Goldstick, Stachys N. Muturi and Paul Rimmerfors. 1993. TR No. 10. ISBN 9966-896-13-9

Twenty years of soil conservation in eastern AfricaLill Lundgren. 1993. TR No. 9. ISBN 9966-896-12-0

Improving livestock production in Babati District, TanzaniaJosef Jonsson, James Kahurananga and Augustine Macha. 1993. TR No. 8. ISBN 9966-896-10-4

Parks and people—pastoralists and wildlife: proceedings from a seminar on environmental degradation in and around Lake Mburo National Park, UgandaJones R. Kamugisha and Michael Ståhl. 1993. TR No. 7. ISBN 9966-896-09-0

The catchment approach to soil conservation in KenyaYeraswarq Admassie. 1992. TR No. 6. ISBN 9966-896-08-2

Lake Babati, Tanzania, and its immediate surroundings: part II—management and action planJames Kahurananga. 1992. TR No. 5. ISBN 9966-896-06-6

Lake Babati, Tanzania, and its immediate surroundings: part I—baseline informationJames Kahurananga. 1992. TR No. 4. ISBN 9966-896-05-8

Miljöprofil Kenya (in Swedish)Lill Lundgren. 1992. TR No. 3. ISBN 9966-896-04-X

The wild lake: the 1990 floods in Babati, Tanzania—rehabilitation and preventionC.Å. Gerdén, G.M.O. Khawange, J.M. Mallya, J.P. Mbuya and R.C. Sanga. 1992. TR No. 2. ISBN 9966-896-01-5

The revival of soil conservation in Kenya: Carl Gösta Wenner’s Personal Notes 1974–81Arne Eriksson (ed). 1992. TR No. 1. ISBN 9966-896-00-7



Maimbo M. Malesu Joseph K. Sang,

Orodi J. Odhiambo, Alex R. Oduor,

Meshack Nyabenge.

Regional Land Management Unit (RELMA-in-ICRAF)World Agroforestry Centre (ICRAF)

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Published by

The SearNet Secretariat, Global Water Partnership Associated Programme of

RELMA-in-ICRAF. World Agroforestry Centre, ICRAF House, United Nations Avenue, Gigiri.

P.O. Box 30677 – 00100, Nairobi, Kenya.

2006 Regional Land Management Unit (RELMA-in-ICRAF), Netherlands Ministry of Foreign

Affairs and Swedish International Development Cooperation Agency (Sida).

Editor of GWP-AP in RELMA Series of publications

Alex R. Oduor, Development Specialist: Information and Publications.

Cover photographs

Alex R. Oduor

Design and Layout

Logitech Ltd

P. O. Box 1003 - 00100

Nairobi, Kenya

Cataloguing in publication data

Maimbo M. Malesu, Joseph K. Sang, Alex R. Oduor, Orodi J. Odhiambo & Meshack Nyabenge.

Hydrologic impacts of ponds on land cover change: Runoff water harvesting in Lare. Kenya. 2006.

Technical Report No. 32 Nairobi, Kenya: Regional Land Management Unit (RELMA-in-ICRAF),

Netherlands Ministry of Foreign Affairs and Swedish International Development Cooperation Agency

(Sida) 41p + xii includes bibliography.

ISBN: 92 9059 197 8

The contents of this book may be reproduced without special permission. However, acknowledgement

of the source is requested. Views expressed in the GWP-AP of RELMA series of publication are those

of the authors and do not necessarily reflect the views of RELMA-in-ICRAF.

v

Contents

Foreword .........................................................................................................................vii

Preface ..........................................................................................................................viii

Acknowledgement ..........................................................................................................x

Acronyms ........................................................................................................................xi

Chapter 1: Introduction .................................................................................................. 1

Chapter 2: Lare division ................................................................................................. 42.1 Location ............................................................................................................................ 42.2 Climate .............................................................................................................................. 52.3 Soils . 72.4 Land use and land cover ................................................................................................. 92.5 Hydrologic characteristics ............................................................................................. 10

Chapter 3: Hydrologic impact of land cover change in Lare ....................................123.1 Land cover change ......................................................................................................... 123.2 Impact of land use change on the hydrology of Lare division ..................................... 143.3 Contribution of land cover change to adoption of rainwater harvesting .................... 18

Chapter 4: Rainwater harvesting technology in Lare ...............................................194.1 Rainwater harvesting systems ...................................................................................... 194.2 Technical issues in the case of Lare ............................................................................ 204.3 Storage for ground catchment systems ...................................................................... 224.4 In-situ rainwater harvesting .......................................................................................... 264.5 Adoption of rain water harvesting ponds ..................................................................... 29

Chapter 5: Impacts of rainwater harvesting ..............................................................315.1 Social impacts ................................................................................................................ 315.2 Economic impacts .......................................................................................................... 335.3 Environmental and ecological impacts ........................................................................ 34

Chapter 6: Conclusions and recommendations ........................................................356.1 Conclusions .................................................................................................................... 356.2 Recommendations for replication of rainwater harvesting ......................................... 35

References ....................................................................................................................37

Annexes .........................................................................................................................38Annex 1: Log sheet for ground truthing ............................................................................... 38Annex 2: Field Questionnaire ............................................................................................... 39Annex 3: Key informants ....................................................................................................... 41Annex 4: Percentage of land cover. ...................................................................................... 41

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List of Figures Figure 2.1: Location of Lare division ..................................................................................................4Figure 2.2: The mean monthly rainfall for Egerton University Rainfall Recording Station ..............5 Figure 2.3: The Agro-Ecological Zone of Lare division .......................................................................6Figure 2.4: Soils of Lare division .........................................................................................................8Figure 2.5: Streams in Lare division ..................................................................................................11Figure 3.1: Land cover maps for Lare and its surroundings in 1973, 1986 and 2003. .............. 12Figure 3.2: A graph showing the percentage changes of different land cover over time .............13Figure 3.3: Change in total annual rainfall observed at Egerton university Rainfall Recording Station .............................................................................................14Figure 3.4: Change in mean monthly streamflow ...........................................................................15Figure 3.5: Variation in seasonal mean streamflow .........................................................................16Figure 3.6: Variation in seasonal maximum streamflow ..................................................................16Figure 4.1: Rain days at Naishi ......................................................................................................... 20Figure 4.2: A schematic diagram showing components of a typical Lare pond system ...............24Figure 5.1: Savings in time and distance .........................................................................................31

List of PlatesPlate 1.1: Ground-truthing the Quickbird image based map ...........................................................3Plate 2.1: Typical landuse for farmers practicing rainwater harvesting .........................................9Plate 2.2: Dairy animals being fed on banana and grass cuttings. ..............................................10Plate 3.1: Continued encroachment into forestlands in the upper part of the watershed ........13Plate 3.2: Makalia River during the dry season of 2006 ...............................................................17Plate 4.1: Gathurere, a crucial community managed earth dam ................................................ 23Plate 4.2: RWH ponds (a) designed water storage pond and (b) former quarry site used for RWH. .............................................................................................. 23Plate 4.3: Trench with correct gradient to check on both sedimentation and erosion ............... 25Plate 4.4: A section of the Quickbird image ................................................................................... 29Plate 5.1: Both men and women ferry water from the river. ......................................................... 32Plate 5.2: Improved Kamau Kuria homes in the background of former building .........................34

List of Tables Table 2.1: Agro-Ecological Zones of Lare division ............................................................................7Table 2.2: Characteristics of Lare soils .............................................................................................8

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Foreword

RELMA-in-ICRAF undertook a technical study of the extensive and successful adoption of rainwater harvesting (RWH) in Lare division, Nakuru district, Kenya. The technical study aimed at generating and documenting the scientific knowledge and experiences associated with rainwater harvesting in the division. This is meant to be used in upscaling and replicating rainwater harvesting in other areas with similar hydro-climactic conditions.

The local community, who are mainly made of immigrant population, settled in the area in the late 1970s. Settlement continues to date in the surrounding areas such as Likia, Mauche and Mau Narok. These settlements have resulted in continued removal of the natural land cover, mainly deforestation, in favour of agricultural activities. The changes in land cover could be associated with the decline in the streamflow amount in the area. Most of the rivers in the area dries up during the dry season which is a cyclic phenomena every three to four years.

To cope with these changes, the local community has adopted simple rainwater harvesting techniques, with minimal support and advocacy from government agencies and local Non-Governmental Agencies (NGO). In turn, there has been widespread socio-economic and environmental impact of rainwater harvesting. The farm income has increased tremendously, while environmental conservation has been enhanced through agroforestry whereas agricultural drudgery has been reduced.

This book highlights how changes in land use has caused changes in hydrologic regime and how this has contributed to adoption of rainwater harvesting in Lare division. It also highlights on the extent and impact of the adoption of rainwater harvesting in the area.

Chin Ong.Project managerRELMA-in-ICRAF

viii

Preface

Land cover changes affect the hydrological regime of an area. These effects are manifested at different spatial and temporal scales. In the 134 km2 Lare division of Nakuru district, there has been extensive deforestation due to the socio-political motivated settlement in the area. Deforestation could be linked to the prevailing water and food insecurity in the division. To cope with changes in the hydrologic regime due to land cover change in Lare division, the local populace have successfully adopted rainwater harvesting. Rainwater harvesting is the collection, conveyance, and storage of rainwater for various purposes. The successful adoption of rainwater harvesting in Lare division has been a showcase of how rainwater harvesting can transform landscapes and livelihood within a relatively short time.

This study utilised LandSat information, Quickbird images and field survey to establish the impact of land use and land cover changes on the local hydrologic regime and how these have contributed to the successful adoption of rainwater harvesting in Lare division. Field interviews tapped on local and logical scientific knowledge from pre-selected key informants.

The analysis of LandSat images established that adjacent forest cover has been reducing by 0.78% of the original area in 1973. Analysis of long term rainfall data also established that there has been a decline in the total annual rainfall amount. This has had significant impact on the hydrologic regime in the division. The maximum and mean dry and wet seasonal flow volume has been consistently declining over the last 40 years. This could be attributed to changes in climate, land cover or both. However, it has resulted in acute water shortage especially during the dry season and consequently food insecurity.

To cope with this acute shortage of water, the local community in Lare division has adopted rainwater harvesting as a coping mechanism. The analysis of the Quickbird image revealed that the adoption rate was nine ponds per square kilometer. The successful adoption of rainwater harvesting in the area is attributed to the consistent

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collaborative effort of the various stakeholders in the area. This included government agencies, research institutions, private sector and NGOs. Rainwater harvesting has had a significant impact on the socio-economic life of the local populace.

It was therefore concluded that rainwater harvesting could be a coping mechanism against the impact of land use/land cover change on hydrologic regime. From this study it was recommended that rainwater harvesting should be extended to areas with hydro-climatic conditions. To successfully promote rainwater harvesting, there is need for persistent and consistent advocacy, strategic collaborations between key players, improved rainwater harvesting system design, increased farm output marketing, provision of technical documentation and exchange trips to the successful farmers by potential adopters.

x


Acknowledgement

The authors sincerely acknowledge the entire SearNet secretariat and RELMA-in-ICRAF staff, who contributed immensely to the success of this study. Special thanks go to Ms. Naomi Njeri, who tirelessly assisted with the required logistics. The ICRAF GIS’ unit, is also acknowledged for preparing the required maps, information and equipments for the fi eld study. Covenant Tours Limited (CTL) who provided transport services to the authors during the fi eld study is highly appreciated.

Special gratitude goes to the hardworking farmers of Lare division. They have worked hard, not only to increase their farm income, including food and water security but also to be a leading example in rainwater harvesting. We also wish to thank the Divisional Agricultural Offi cers and the staff of Mtakatifu Clara Training and Development Centre in Lare division for guiding the fi eld study and providing pertinent information about the division. Special recognition goes to the effort and dedication of Mr. Karanja Mwangi, who spared his time for us during the fi eld survey.

The authors also wish to thank the Egerton’s SUMAWA project research team, who provided the hydrologic information of the nearby Njoro watershed, which is undergoing the same land use/land cover changes as Lare division. Dr. Gichaba is specially recognised for spending time to provide the required hydrologic data and also visit the farmers in Lare division.


xi

Acronyms

CDF Constituency Development FundCDN Catholic Diocese of NakuruCSD Commission for Science and DevelopmentEU European UnionFSK Farming Systems KenyaFTC Farmers Training SchoolGI Galvanised Iron sheetGPS Global Positioning SystemICRA International Centre for Development-Oriented Research in

AgricultureICRAF World Agroforestry CentreILRI International Livestock Research InstituteKARI Kenya Agricultural Research InstituteLH Lower HighlandsRELMA Regional Land Management UnitRRS Rainfall Recording StationRWH Rainwater HarvestingSUMAWA Sustainable Management of WatershedTWDB Texas Water Development BoardUM Upper midlands


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Chapter 1

Introduction

Access to safe and suffi cient water by rural households will result in increased agricultural yields, improved hygiene and sanitation. It will also save time and reduce drudgery thus releasing women and children to participate in other productive and social activities. However, this access to safe and suffi cient water is compromised by human activities, which alter the natural land cover in a watershed. Land cover changes include deforestation, intensifi cation of agriculture, drainage of wetlands and urbanization (Calder, 1992). The most common of these changes in Lare is the extensive encroachments into forestlands and grasslands. Encroachment into forestlands is known to affect the hydrologic characteristics of a watershed. Forests, especially those that are riparian, are associated with watershed services such as control of erosion, restriction of pollutants and regulation of streamfl ow.

Continued land cover changes in Lare division and its environs, has had signifi cant impact on the local hydrologic regime, due to increased settlements and expansion of agricultural activities. Krhoda (1988) predicted the effects of poorly planned land use and clear felling of trees in the Eastern slopes of Mau forest. According to his hydro-geological assessment, “…any type of resource utilization in the Mau Hills forest will have some impact on the hydrological regime. Whatever method of land use is applied, it will be necessary to exercise strict management practices”. These impacts include changes in streamfl ow characteristics such as seasonal mean and maximum fl ows, which determine availability of water especially during the dry seasons. A visit to Lare will confi rm that the area experiences acute shortage of water during the dry season. In deed the local community spends a lot of time, fi nances and energy looking for water.

To cope with these changes in the hydrologic regime, the local community have extensively and successfully adopted rainwater harvesting techniques that are relatively simple and easy to apply. Rainwater harvesting is the capturing, diversion, and storage of rainwater for a number of different purposes including landscape irrigation, drinking

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and domestic use, aquifer recharge, and storm water abatement (TWDB, 2005). It is an ancient technique which enjoys a revival in popularity due to the inherent quality of rainwater. Rainwater harvesting in Lare has been a showcase of how it can transform landscapes and livelihoods within a relatively short time (Mati, 2004).

RELMA-in-ICRAF undertook a technical study of the Lare rainwater harvesting ponds in order to generate scientifi c knowledge that highlights the basis for the success and document the experiences associated with rainwater harvesting. This was meant to provide relevant knowledge to be used to upscale and replicate rainwater harvesting in other areas with similar hydro-climatic conditions. The nature of the study called for a comprehensive approach to data collection, application of remote sensing in mapping and fi eld survey to provide the necessary information for a technical description and evaluation of the its adoption in the division.

The objective of the study was to identify the impact of land cover change on the local hydrologic regime, how it has contributed to the successful adoption of rainwater harvesting and to generate technical information on the effectiveness, socio-economic and environmental impacts of the rainwater harvesting in Lare Division.

To achieve this objective, a series of two studies were carried out . The fi rst study was a three-day exploratory one, which focused on three households who practiced rainwater harvesting. In this study, direct questions, open-ended and structured questionnaires were administered to pre-selected male and female members of households, as well as a local facilitator and the divisional Forest Extension Offi cer. Field observations and evaluation of the structural works on the ponds were also done.

The study collected information on the technical components of rainwater harvesting. Socio-economic and environmental issues pertinent to the adoption and use of rainwater harvesting were also evaluated while focusing on land and water conservation, biodiversity, tree planting, erosion control, improved sanitation and aesthetics.

In the second study, analysis of a series of LandSat imagery based land cover maps was done to determine the land cover change in the area. The changes were compared to seasonal changes in streamfl ow amount from the nearby Njoro watershed. In addition, a high resolution Quickbird image was used to determine the rate and extent of rainwater harvesting adoption in the area. GPS supported ground truthing was undertaken for the LandSat maps whereas the Quickbird was ground-truthed with the aid of the local community members (Plate 1.1). In addition, another fi eld survey carried out during this study tapped farther into the local knowledge and socio-economic impact of rainwater harvesting.


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Plate 1.1: Ground-truthing the Quickbird image based map

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Chapter 2

Lare division

2.1 Location

Lare division is located in Nakuru district of Rift Valley province, Kenya, as shown in Figure 2.1 below. The division is bounded by latitude 350 57’ 25” E and 360 04’ 25” E and longitude 00 22’ 20” S and 00 32’ 50” S. It covers about 134 km2 and has four administrative locations. These locations are Naishi, Naishi game, Pwani and Bagaria. The area population is about 20 000 based on 1999 population census.

Figure 2.1: Location of Lare division


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2.2 Climate

Lare division receives a medium bimodal and unreliable rainfall amount. The area receives on average about 600 - 1000 mm per annum. The rainfall falls mainly in March (long rains) and October (short rains). The mean monthly rainfall for the nearby Egerton University Rainfall Recording Station (RRS) is shown in Figure 2.2. The short rain gradually tapers-off into December (Migwi, 2006). In addition, the area also experiences a cyclic drought every 3-5 years (ICRA, 1997)

0

40

80

120

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Time (Month)

Rain

fall

(mm

).

12.0

14.0

16.0

18.0

Tem

pera

ture

(0

C).

Monthly rainfall Annual mean

Monthly temperature Mean temperature

Source: Jaetzold and Schmidt, 1983

Figure 2.2: The mean monthly rainfall for Egerton University Rainfall Recording Station

Lare division is characterized by agro-ecological zones LH3, LH2, UM4 and UM5 as shown in Figure 2.3 and defi ned by Jaetzold and Schimdt, (1983). The characteristics of this agro-ecological zone are summarised in Table 2.1.

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Figure 2.3: The Agro-Ecological Zone of Lare division


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Table 2.1: Agro-Ecological Zones of Lare division

Agro ecological zones

Cropping season Good yield potential Fair yield potential

UM4 Sunfl ower- maize zone

Two variable cropping seasons

The fi rst rains start at end of march. The major crops for this season are maize, beans, sorghum, and sunfl ower. Sisal and eucalyptus trees are grown throughout the year.

Potential crops grown are: fi nger millet, pigeon peas, sweet potatoes, egg plants, cabbage, Soya bean, onions, kales, paw paws, and mangoes

UM5 Livestock-sorghum zone

A weak short cropping season, long rains with a second period of short rains.

No good yield potential except with additional irrigation.

Sorghum, sisal, and Marama beans.

LH3Wheat/(maize)-Barley zone

A long to very cropping season

The fi rst rains start before April and the suitable crops for this season are wheat and Barley.

Late maturity, maize, peas, linseed late sunfl ower, vegetables.

LH2Wheat/maize-pyrethrum zone

Very long cropping season divided into two variable season

First rain in mid-March. Suitable for late maturity wheat, peas, potatoes, sunfl ower, barley.

Suitable for fi nger millet, beans, onions and tomatoes.

Source: Jaetzold and Schmidt, 1982

2.3 Soils

Soils in Lare division and its surroundings vary with elevation. The soils are mostly volcanic, well drained and moderately deep. These soils are generally very fragile loam to sandy loam and are vulnerable to soil erosion. The colour varies from deep brown to dark grey depending on the drainage pattern of the locality. The distribution of various soil types in Lare division is shown below in Figure 2.4, whereas their characteristics are summarised in Table 2.2.

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Figure 2.4: Soils of Lare division

Table 2.2: Characteristics of Lare soils Soil Characteristics

H6 Complex of• Well drained, deep to very deep, dark brown to greyish brown, friable and smeary clay

loam with a thick humic topsoil (Mollic Andosol)• somewhat excessively drained, shallow, strong and rocky soils of varying colour and

consistence and texture (dystric REGOSOLS, lithic phase with ferralic CAMBISOLS, Lithic phase and rock outcrops)

H10 Complex of well drained to moderately well drained, shallow to moderately deep, dark brown, fi rm, strong clay loam to clay in places with humic topsoils (Eutric REGOSOLS) partly with lithic phase; with Verto-Luvic PHAEOZEMS, partly lithic phase.

Pv9 Well drained, moderately deep to deep brown, to dark brown very friable loam to sandy to clay loam (Vitric ANDOSOLS)

Um4 Well drained deep to extremely deep, dark red, friable clay with a thick humic topsoils (mollic NITOSOLS with Nitro-luvic PHAEOZEMS)

Source: Sombroek et al, 1982


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2.4 Land use and land cover

Land cover is the observed biophysical cover on the earth surface, whereas land use is characterized by the arrangements, activities and input people undertake in a certain land cover type to produce changes or maintain it (Di Grerogio, 2005). Land-use is determined by environmental factors such as soil characteristics, climate, topography, and vegetation. The major Land cover in the area is mainly agricultural land. There are also some forest and dense bushlands. It is worth noting that the land use and land cover has been changing over time.

Land use in Lare division is varied. The major land use is mixed farming, where crops are grown and dairy cows are kept (ICRA, 1997). Crops grown in the area include maize, wheat, beans, peas and vegetables. Livestock, however, forms an important sub-sector in the division as it helps meet the requirements for various products at both household and market level. There is also an active informal market for surplus livestock products e.g. milk, meat, live animals, and eggs. These generate income for the households and local economy.

Socio-political factors have contributed immensely to the continued settlement in the division and its surroundings (Krupnik, 2004). The settlement has caused extensive land cover changes. Large tracts of forestlands were excised and sub-divided into private land tenure systems. The individual household farms range from four to ten hectares (10-25 acres) in size. However, due to population increase, there is an increasing trend towards further land sub-division. This reduces the average farm size per household. Apart from individual land, some areas have been set aside for community amenities which include schools, community dams and business markets.

Plate 2.1: Typical landuse for farmers practicing rainwater harvesting

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Plate 2.2: Dairy animals being fed on banana and grass cuttings.

2.5 Hydrologic characteristics

Lare division is drained by ungauged streams which rise mainly from the Mau forest. The main river fl ows through the division (Figure 2.6) into the 44 km2 endorheic Lake Nakuru. The Lake is a Ramsar site famous worldwide for its lesser fl amingos (Phoeniconaias minor). Most of these streams dry up during the dry season.

Scarcity of water both for human and livestock use, particularly during the dry season, is a major problem affecting about 70% of households in the area (ICRA, 1997). Since tap water is not available to most of the households in the division, the community relies on boreholes, roof water catchments, dams, water pans and a few seasonal rivers to meet their domestic and livestock water requirements.

Adoption of water harvesting in the division has been very impressive. In 1998, about 409 households had runoff harvesting systems. These increased to about 1,030 households by the end of 1999, an increase of about 150%. It was approximated that over 4,000 households had water harvesting systems by August 2004.


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Figure 2.5: Streams in Lare division

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Chapter 3

Hydrologic impact of land cover change in Lare

3.1 Land cover change

The respective land cover change derived from LandSat based maps for the years 1973, 1986 and 2003 are shown in Figure 3.1. The spatial extent of each land cover class for the different years can be visualized from Figure 3.1 and is further summarized in Annex 5. In general, the major land cover classes in Lare division and its surroundings are forests, agricultural lands, grasslands and shrublands.

Figure 3.1: Land cover maps for Lare and its surroundings in 1973, 1986 and 2003.

Ground truthing revealed that the maps refl ected actual land cover classes in the area. At Mwerigo, the grasslands and expansion of Nakuru town was observed whereas at Mauche area near Likia, the expansion of agriculture was also seen. Historical ground


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truthing using information provided by key informants showed that the maps of 1986 and 1973 with the conditions at those times. It was established that settlement began in the areas around 1978 when the farms were excised from the forest. They were then sub-divided into small privately owned farms of two, four or ten hectare sizes. People cleared the forest and expanded agricultural activities in the area. Thereafter, settlement extended to other areas in the upper part of the catchment. Currently, deforestation is continuing (Plate 3.1) without due consideration of the upstream-downstream linkage in a watershed.

Source: SUMAWA

Plate 3.1: Continued encroachment into forestlands in the upper part of the watershed

When the three maps were compared, it was observed that the spatial extent of the various land cover classes have been changing over time. The changes are shown in Figure 3.2.

y = 1.52x - 2980.47

y = -0.78x + 1583.52

y = -0.35x + 714.38

y = -0.46x + 924.78

y = 0.10x - 186.24y = -0.02x + 51.96

y = 0.00x - 7.930

20

40

60

80

1970 1975 1980 1985 1990 1995 2000 2005

Time (year)

Per

cen

tage

lan

d c

over

ch

ange

Cropland Forest Shrubland Grassland Settlement Water Bareland

Figure 3.2: A graph showing the percentage changes of different land cover over time

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The maps gave evidence of continued deforestation and increased agricultural activities over the last 20 years. The initial 36.1% in 1973 forest cover has been reduced by about 0.78% annually to the current 12.3%. Shrublands and grasslands have also reduced from the initial 18.1% and 15.9% by 0.35% and 0.46% per annum respectively. On the contrary, the cropland has increased from the initial 22.1% in 1973 at a rate of 1.5% per annum to the current 67.7%.

Though a linear relationship was assumed in the trend analysis, it may not be as simple as shown in Figure 3.2. There could have been periods where settlements were accelerated and deforestation decelerated. Given that settlement in the area is motivated by socio-political factors, the settlement may not be linear. In fact, SUMAWA called the year 1986 a change period. After 1986, where the afforestation slogan “kata moja panda mbili” was also abandoned and settlement accelerated, large tracts of land were deforested in the area.

3.2 Impact of land use change on the hydrology of Lare division

Based on Njoro watershed streamfl ow data, it was observed that there has been some variation in the amount of water over time. The local streamfl ow regime has been affected with most of the rivers in the area drying up during the dry season. This was seen from analysis of long term streamfl ow data, during the fi eld survey and from key informants.

The mean annual rainfall has been changing over time (Figure 3.3). This was based on the analysis of data from Njoro watershed by SUMAWA.

0

200

400

600

800

1000

1200

1400

1600

1800

Tota

l Ann

ual R

ainf

all (

mm

)

1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005Time (year)

y = 2.0823x + 5126.3

Total annual rainfall 3 per. Moving Avg. (Tot. annual rainfall)

5 per. Moving Avg. (Tot. annual rainfall)

5 per. Moving Avg. Tot. annual rainfall)

Source: SUMAWA

Figure 3.3: Change in total annual rainfall observed at Egerton university Rainfall Recording Station


15

The total annual rainfall has been decreasing at a rate of approximately 2 mm over the last 60 years as shown in Figure 3.4. The change in rainfall is attributed to the overall climate change or feedback mechanism due to land cover changes in the division and its wider environs. Given that availability of water is a problem for both domestic and agricultural use, the decrease in rainfall is alarming even though farmers have adapted to rainwater harvesting.

Analysis of streamfl ow data depicts the long term changes in streamfl ow as observed in the Njoro watershed. The changes are shown in Figure 3.4 to Figure 3.6.

y = -0.0043x + 5.2299R2 = 0.0623

0

2

4

6

8

10

Jan-60 Jan-64 Jan-68 Jan-72 Jan-76 Jan-80 Jan-84 Jan-88 Jan-92

Time (month)

Meanflow(m

3 /s)

Figure 3.4: Change in mean monthly streamfl ow

16


0

2

4

6

8

10

1960 1970 1980 1990 2000

Time (year)

Meanflow(m

3 /s)

Wet Dry

Figure 3.5: Variation in seasonal mean streamfl ow

0

20

40

60

80

100

Meanflow(m

3 /s)

1960 1970 1980 1990 2000

Time (year) Wet Dry

Figure 3.6: Variation in seasonal maximum streamfl ow


17

There have been some variations in the hydrologic regime of Lare division, as shown by the streamfl ow data from neighbouring Njoro watershed. The Njoro watershed has undergone the same land use and land cover changes as that of Lare. The maximum and mean streamfl ow of both dry and wet season has been declining over time. Linear trends show that future supply of water from the streams in the area is diminishing and could be more unreliable in the future.

The variation in streamfl ow could be attributed to the change in climate, land use and land cover or both. Despite the fact that the total annual rainfall amount has been declining with time at an average rate of 2 mm per annum, it is unlikely that this alone contributed to the variation in streamfl ow that is being experienced in the area. Therefore, the other major change that affects streamfl ow is land cover and could be linked to the current variation in streamfl ow.

According to key informants, the local community recognised the impacts of forest cover removal on the streamfl ow and micro-climatic conditions of the division especially the rainfall regime. Most farmers said that the continued settlement in the area has affected seasonal rainfall characteristic. They also know that as a consequence of continued settlements in the area especially in the upper parts of the watershed, the local streamfl ow regime has been affected. For example, the River Makalia (Plate 3.2), which used to overtop its bank making it impossible to cross in the 1980s, currently dries up during the dry season, and was indeed dry during the fi eld survey. Another aspect of the impact is on Lake Nakuru, which is slowly receding.

Plate 3.2: Makalia River during the dry season of 2006

18


3.3 Contribution of land cover change to adoption of rainwater harvesting

Based on the information gathered from the key informants, it was established that the removal of forest cover especially the riparian vegetation has had a signifi cant impact on the streamfl ow regime. Farmers in Lare division acknowledged that removal of forest cover in the area to pave way for settlement has resulted in reduced streamfl ow. They also acknowledge that the removal of forest cover has affected the micro-climate of the division and its environs.

Settlements result in extensive deforestation. Such deforestation which replaces perennial tree cover by seasonal crop cover leaves the soil surface without adequate cover to prevent the impacts of rainfall and winds. Lack of adequate vegetation cover (to reduce the velocity of fl ow) suggests that there is little time available for rainwater to infi ltrate into the ground. This consequently results in low groundwater and high runoff.

To improve on their livelihood and cope with the effect of water shortage, the Lare community had to adopt rainwater harvesting. Most of them harvest road runoff and store it for both domestic and agricultural use during the dry season. Luckily, the farms are located slope-wise hence harvesting road runoff is easy, as runoff is diverted from the roads and conveyed via mitre drains, into the ponds.

Farmers are also using the harvested water to increase the land cover through agroforestry. Most of the farmers have tree nurseries and some have woodlots. This provides the much needed land cover though not extensively. Farmers hope to increase further, the land cover.


19

Chapter 4

Rainwater harvesting technology in Lare

4.1 Rainwater harvesting systems

There are several terminologies used to describe the type and function of a rainwater harvesting system. Based on the catchments, the rainwater harvesting systems can be classifi ed into roof or ground catchment systems, while based on the storage systems they can be classifi ed us cistern or pond systems. rainwater harvesting systems can also be classifi ed based on their usage, for example for agriculture, livestock, domestic, environmental, eco-tourism or industrial. In Lare, the most common rainwater harvesting systems are for domestic and agriculture.

In the roof or ground rainwater harvesting catchment systems, water is collected from roof tops, courtyards and similar compacted or treated surfaces for domestic, livestock, environmental or garden use. These systems can be applied at micro or macro scales. The micro-catchment rainwater harvesting is a method that collects surface runoff from a small catchment area and stores it in the adjacent infi ltration basin. The basin can be planted with a tree, bush or annual crops. In the macro-catchments rainwater harvesting, also called harvesting from external catchments, runoff from hill-slope catchments and external surfaces is conveyed to the storage or usage located at a foot hill or on a fl at terrain.

In cistern or pond storage systems, the design and operation of the system is hinged to the storage facility with various tank confi gurations that can be adapted for various uses. The placement and location of the tank, material used, its cost, rainfall amounts and water demands are critical in describing the rainwater harvesting system employed.

20


4.2 Technical issues in the case of Lare

The most important technical issues in the case of rainwater harvesting in Lare mainly relate to design parameters. The most important parameters that should be considered in identifying areas that are suitable for RWH are rainfall, catchment characteristics and storage.

4.2.1 Rainfall characteristics

The knowledge of rainfall characteristics (intensity and distribution) for a given area is a pre-requisite for designing a RWH system. The availability of good quality rainfall data is important for establishing the rainfall-runoff processes and determining available soil moisture for agricultural systems. Useful rainfall factors for the design of a rain or fl oodwater harvesting system include: number of days the rain exceeds the threshold rainfall of the catchments on a weekly or monthly basis; probability and occurrence (in years) for the mean monthly rainfall; probability and re-occurrence for the minimum and maximum monthly rainfall; and frequency distribution of storms of different specifi c intensities.

As discussed in section 2.2., Lare experience a bimodal rainfall which peaks in April and sub-peaks in August. The number of rain days follows a similar pattern as the monthly rainfall shown in Figure 4.1. Therefore, the harvested rainfall during the short rains should be conserved for the six to seven months dry period. For design purposes, the short rains which contribute 40% of annual rainfall and precede the dry period is the most critical.

No of rainy days

02 4 6 8 10 11 14

5

10

15

20

25

Days

Months2004 2004

Source: FAO Africover

Figure 4.1: Rain days at Naishi


21

4.2.2 Catchment characteristics

In Lare, two typical catchment systems are used for rainwater harvesting. These are roof water harvesting catchment and ground systems. Roof water harvesting is a practical development option for areas with insuffi cient ground water and no perennial rivers. Roof water harvesting from schools, churches and individual houses with corrugated roofs are practiced to provide adequate water during the rainy season. Most houses in Lare are made of corrugated galvanised iron (GI) roofi ng sheets providing suitable catchments for rainwater harvesting.

The three farms considered during the exploratory study practiced roof top catchments system, where water collects from the Galvanised Iron (GI) roofs and is stored in tanks whose volumes are given below.

Name of farmer Storage tank m3

Kamau Kuria 5

Samwel Njogu 10Bernard Maina 20Mean 11.7

Water from the tanks is used for drinking, cooking, washing and bathing. Water used for drinking water is boiled before use. Water is delivered through a tap for the GI tank while cups and buckets are used to draw water from the drums.

22


Most farmers in Lare have adopted various components groundwater catchment systems to suit their individual needs. However, the catchments characteristics that infl uence the amount and quality of run-off are the land cover, topography, hydrological processes and the existing infrastructure summarised in box below.

Vegetation This is an important parameter that affects the surface runoff. An increase in the vegetation density results in a corresponding increase in interception losses, retention and infi ltration rates which decrease the volume of runoff. There is a high degree of congruence between vegetation density and suitability of the soil for cropping. Most of the runoff is from hard surfaces formed by roads and paths which fi nd their way to the road drains. Terrain This is another important parameter that determines the type of RWH system. Length and gradient of slope are important characteristic for determining suitability of a given terrain for RWH. The Lare landscape is characterized by steep gradients with the land rising over 300m in a 5km stretch providing an ideal situation for increased runoff fl ows.

Soil The type and depth of soils also determine the suitability of an area for catchments or cropping in RWH. This will infl uence infi ltration rate and the storage capacity of a soil. In Lare at the onset of the rains, the seepage rates are in the range of 16-24 mm/hr. Though this is high and can make the area unsuitable for un-lined pond structures, the silt laden run-off seals the pores of the soil forming the base of the pond thus reducing seepage signifi cantly.

4.3 Storage for ground catchment systems

Once runoff has been diverted from the paths and roads and other suitably pre-treated surface, the water is stored in various suitable structures. In Lare, these include earth dams and ponds.

4.3.1 Earth dams

Earth dams are temporary structures constructed with locally available materials to impede the soil and water removed from the watershed. It is constructed across rivulets and gullies to control soil erosion, prevent gully formation and direct the fl ow of water underground. These obstructions are useful as soil and moisture conservation measures.


23

Plate 4.1: Gathurere, a crucial community managed earth dam

4.3.2 Ponds

Ponds are storage systems which are multipurpose conservation structures depending on their location and size. They are simple to construct and the most common type of pond is the excavated one. It is constructed by excavating a depression, forming a small reservoir or by constructing an embankment in a natural gully to form an impounded reservoir. It serves for 3-6 months and largely during the rainy season. Abandoned quarry sites also form depressions for water collection and can be adapted to serve as ponds (Plate 4.2).

`Plate 4.2: RWH ponds (a) designed water storage pond and (b) former quarry site used for RWH.

24


The following factors need to be considered when designing, locating and constructing a pond:

• It should not be located in heavy soils or soils with impervious strata; otherwise the top soil should be porous.

• Suitable and adequate soil should be available for forming the embankments.• Simple, economic and effi cient surplus arrangement should be possible.• Pond size should be decided on the basis of the catchments area and the number of

fi llings possible for the pond in the area.

The main components of a pond system are the catchment area (roof, ground and road) diversion channel, de-silting chamber, the pond reservior and fi nally the delivery system. The component of this rainwater harvesting system are shown in Figure 4.2 below

a

a

b

c

d

e

a

a

bc

d

e

The catchments

Components of the pond system

Diversion channel

De-silting chamber

Reservoir

Delivery system

Figure 4.2: A schematic diagram showing components of a typical Lare pond system

A small “check dam” is used to divert road runoff into a diversion channel. Simple cross-sectional shapes such as triangles, trapezoids and semi-circles are used as representative collectors or diversion channels. These are completely characterized by slope, length, cross sectional dimensions, shape and Manning’s ‘n’ value.


25

Plate 4.3: Trench with correct gradient to check on both sedimentation and erosion

The most critical design parameters considered by the farmers in Lare are length and slope of the channel. The ponds are located just off the roads to ensure shorter channel lengths.

Before the runoff enters the pond, they go through a de-silting chamber. The chambers are designed to reduce the sediment load in the runoff getting into the ponds. This leads to off–loading most of the sediments. This reduces the frequency of de-silting the ponds and ensures a higher operating storage capacity for the system. After the de-silting chamber, the runoff goes to the storage pond via another channel.

From the pond, the water is drawn for use using a bucket and rope system, the treadle pump system or a combination of the two. The treadle pump delivers about 50-200 litres of water per minute depending on the pumping head and strength of the operator.

26


There are two systems for drawing water from the ponds. Kamau Kuria uses a treadle pump whereas Bernard Maina uses bucket and rope system. The treadle pump delivers about 50-200 litres of water per minute depending on the pumping head and strength of the operator. The head difference between the pond and the highest point on the farm is 2 m. Kuria’s family delivers up to 200 liters of water in 5 minutes compared to Bernard Maina who spends 20-30 minutes daily drawing an equivalent amount of water.

4.4 In-situ rainwater harvesting

Another method of rainwater harvesting practised in Lare is the in-situ rainwater harvesting. This method emphasises on water management and conservation structures that were traditionally used for soil conservation. The approach aims at maximum infi ltration and minimum surface runoff to achieve better yields where soil moisture is a constraint. The design and performance of these structures are infl uenced by the soil type and the climate. Clay soils have low infi ltration rates and high moisture storage capacity. This makes them suitable for deep fl ooding for subsequent cropping. Sandy soils have quicker infi ltration and lower storage, thus suitable for diversion schemes as found in Lare. The climate affects the method used.

Two methods are adapted in Lare, that is pitting and runoff farming, to augment rainfall since rain alone is not suffi cient to grow crops.

4.4.1 Pitting techniques

Run-off is collected from off the farm and diverted into the cropped area. The system also doubles as a soil conservation measure and works by containing the farm-generated run-off within the fi elds. Suitable trenches or pits are constructed along the farm contours. Diversion channels divert water from off the farm into these structures. The structures act as infi ltration zones allowing the collected runoff to percolate into the soil and thereby increases the moisture regime in the soils for any given storm.


27

On Bernard Maina’s farm, an elaborate system of diversion canals and farm-based trenches exist for harvesting runoff from the nearby road and diverting it into the farm. The improved soil moisture achieved is used to maintain a pasture crop, grow tomatoes, sweet corn, french beans, maize and normal beans. The system works best to drought proof the fi elds against the moisture depleting effects of high evaporation rates and intra seasonal droughts. According to the farmer, this system has increased the reliability of production giving an increase in food security. Trenches that measure 1.7m wide and 1.3m deep and that span over 73m are found in this farm as shown below. Simple designs are used and constructed using farm labour

28


4.4.2 Runoff farming

Runoff depends on collecting runoff and diverting it onto a cropped area. Runoff from uncultivated and un-terraced land is channelled to grass and forested fi elds.

In Kuria’s farm, run-off from the road is diverted through the path leading to his home and allowed to spread to the fi elds with trees, citrus fruits and banana terraces.

This system improves the soil moisture availability making the land more productive with fewer investments on irrigation infrastructure and labour costs. The impact of this is a lash fi eld of trees, sugarcane and fruits with the attendant fi nancial infl ow.


29

4.5 Adoption of rain water harvesting ponds

Based on the analysis of the Quickbird image, most of the households in Lare division have RWH ponds. A section of the Quickbird is shown in Plate 4.4 below. The red dot indicates the location of the identifi ed ponds, whereas the green dots depict the position of initially unidentifi ed ponds, but added during the ground-truthing exercise.

Plate 4.4: A section of the Quickbird image

30


Most of the ponds in parts of Lare division were identifi ed by the image captured by the Quickbird GIS technology. However, those ponds which were under a shade or covered, were not captured by the Quickbird imagery. On the other hand, natural depressions were in some instances identifi ed as RWH ponds. The key informants identifi ed these discrepancies, which were corrected during the ground-truthing exercise.

The adoption of rainwater harvesting in Lare has been enhanced by numerous trainings, excursions and extension packages offered by both local and international NGO’s and government institutions (KARI and Egerton University). For example, during the two day exploratory study it was established that Kuria’s family has been exposed to different technologies through training at the Mtakatifu Clara Training and Development Centre, Baraka Farmers Training Centre in Molo, excursions and visits to Machakos and western Kenya and personal visits to his home by extension and development agents. Kuria and his wife attend trainings together. Maina and his family have benefi ted from the same system though he attends the trainings without his wife while the Njogu family have had minimal exposures.

The study also noted that absentee land owners have not adopted RWH ponds in the area. Some of them have grown wheat in their entire farm. They also live outside the division and only come once in a while to attend to their wheat fi eld. The other factor that hinders adoption of rainwater harvesting is the type of soil and size of the farms. Some soils have high seepage rates. This was observed in Naishi game location where there is lower adoption rate as compared to Naishi. The reducing farm size due to the continued sub-division hinders adoption of rainwater harvesting. The local community feels that the ponds take up a relatively large area when compared to their small farm size.

Most of the ponds in Lare division are as a result of individual initiatives. However, few such as Gathurere (Plate 4.5) and Mbogua are communal initiatives. They have been developed by the community with the aid of Constituency Development Fund and Catholic Diocese of Nakuru. The communal ponds are managed by hired community members and who are paid on a monthly basis. In turn, the water users who are mostly community members, pay for using the water from the community’s ponds. The water is not only used for domestic purposes but also in community farming activities, which include watering tree seedlings in nearby nurseries and small-scale fi sh husbandry.


31

Chapter 5

Impacts of rainwater harvesting

5.1 Social impacts

The social impacts associated with RWH observed in Lare include impacts on social responsibility, access to clean water and consequently improved health status of the local community. Emergence of new social roles in the area has been observed.

According to the local culture, women and children are primarily responsible for fetching water for domestic use. Gender issues are of particular signifi cance with respect to rainwater catchment systems due to their direct impact on the lives of the rural women. Well-designed roof and ground catchment systems are liberating women from the burden of collecting water over long and hilly terrains (Figure 5.1). However, the prevailing acute water shortage has forced both genders to be involved in the development, operation and maintenance of rainwater harvesting systems. In fact, men have taken a leading role in adopting rainwater harvesting. It could be hypothesized here that families that leave the task of fetching water to women are not responsive to the task of developing independent sources of water supplies.

0

2

4

6

TimeSpend

Distance Man Children Wife Laborers

Parameter

Tim

e hr

s or

Dis

tanc

e km

Kuria without Kuria with Njogu without

Njogu with Maina without Maina with

Figure 5.1: Savings in time and distance

32


Plate 5.1: Both men and women ferry water from the river.

In addition, there are new emerging roles which could be directly related to RWH. Some of these include young men collecting water from the dams for sale. Youth groups who specialise in constructing ponds have also emerged.

Development of RWH systems in Lare has enhanced access to clean water harvested mainly from roof catchments and a times from runoff. This water is used for various domestic needs such as drinking, cooking, washing and bathing. The quality of roof catchment harvested water is superior to that of such alternatives as shallow well water and even deep well water which are perennially polluted with fl uoride. There are simple technologies to improve the quality of harvested runoff for domestic use. The technologies involve the use of aluminium sulphate to reduce turbidity and boiling the water to kill germs.


33

5.2 Economic impacts

The main economic impacts of rainwater harvesting observed in Lare are mainly attributed to associated increased agribusiness activities in the area. The agribusinesses include the production and sale of livestock and farm products. Rainwater harvesting reduce drudgery and generally increase the quantity and quality of farm output especially during the dry season.

The initial cost of investments and the output directly associated with the water use can be used to assess the economic benefi t of adopting rainwater harvesting. The cost of the ponds can be pegged on the time value spent on constructing and operating the system by the benefi ciary families. The ground catchments and pond storage systems were considered as labour-intensive technologies. The initial labour inputs were from the farmer and his household. These systems are maintained and expanded using fi nances from either agricultural, livestock or other productive ventures.

RWH technologies are profi table investments. Systems for horticultural farming and improved livestock rearing make RWH attractive, economical and sustainable for poor rural communities. Respondents from Lare division proved that farm incomes increased in a season due to productive use of harvested rainwater. The cost benefi t analysis of the RWH systems can be conducted. However, in the case of Lare, assumption had to be made and the ability of farmers to recall was relied on, since the local community do not keep any records of their farm output. They only gave estimates of their economic advantage over time, which was considered conservative.

Lare experiences a cyclic drought once in every three years, which cause crop failure. The failure has been reversed and families are experiencing an increased production throughout the year and even during the drought seasons. Crops grown during the dry periods fetch premium prices from the local markets due to high demands, while milk production can be boosted through provision of fodder and water. For example, one farmer testifi ed that her vegetable yield had doubled after she adopted rainwater harvesting and she also no longer buys water for her livestock. In turn, she uses the money to pay school fees for her children.

The households that have adopted RWH systems save an average of US$ 1.1 per day that was spent on labourers who fetched water from other sources i.e. boreholes and dams. Family members have been released from the drudgery of fetching water over long distances, thus participating in productive farm work. The saving in distance and time is shown in Figure 5.1.

Other enterprising farmers have used the harvested water for building and sale. One farmer said that he had earned up to approximately US$ 115 from the sale of water in the year 2004. On the hand, he was using the increased income and harvested runoff to build a masonry house set in the background of pre-rainwater harvesting mud house to the current success of rainwater adoption in his farm (Plate 5.2).

34


Plate 5.2: Improved Kamau Kuria homes in the background of former building

5.3 Environmental and ecological impacts

Generally, the environmental impact of rainwater catchment systems may be minimal. The large scale ground catchment systems for communal supplies and the individual pond systems have had positive environmental impacts, e.g. in reducing storm run off and hence soil erosion and jump starting tree planting in the area. Some concern maybe raised that ground water recharge may suffer in Lare due to the widespread practice of rainwater harvesting in the area. While this maybe true in theory, there are two important facts that should counter any concern. Firstly, the rainwater harvested is stored in ponds and pit structures within the farms and therefore contribute to groundwater recharge through seepage and deep percolation. Secondly, much of the rainwater stored in the ponds is used for irrigation, making it available to recharge the ground water systems.

Dry area ecosystems are generally fragile and have a limited capacity to adjust to change. If the use of natural resources (land and water) is suddenly changed by water harvesting, the environmental consequences are often far greater than foreseen. Consideration should be given to the possible effect on natural wetlands as on other water users, both in terms of water quality and quantity. New water harvesting systems may intercept runoff at the upstream part of the catchments, thus depriving potential down stream users of their share of the resources. Water harvesting technology should be seen as one component of a regional water management improvement project.

Though Lare receives unreliable rainfall, well drained soils and sloping topography provides feasible environment for feasible rainwater harvesting. The ponds in Lare are competing effectively with other sources like boreholes and the seasonal rivers. Trees planted through rainwater harvesting have helped to condition and beautify the environment.


35

Chapter 6

Conclusions and recommendations

6.1 Conclusions

Analysis of the LandSat based maps established that the forest cover has been reducing by 0.78% per annum of the original area in 1973. This deforestation has had signifi cant impact on the hydrologic regime in the division, where the seasonal fl ow amounts have consistently declined resulting in water and food insecurity. To cope with this acute shortage of water, the local community has adopted rainwater harvesting.

Several systems of rainwater harvesting have been adopted in Lare. These include the use of roof catchments, runoff ponds and in-situ rainwater harvesting. However, the use of runoff ponds is the most common system. Quickbird images revealed that, at a density of nine ponds per square kilometer, most households have adopted runoff harvesting ponds, which is a result of the consistent promotional efforts by key stakeholders in the area.

The adoption of RWH has had signifi cant socio-economic and environment impacts in the area. It has reduced agricultural drudgery, saved time spent in fetching water hence releasing the girl child to participate in other productive socio-economic activities including school attendance. Environmental impacts include development of agroforestry and erosion control.

6.2 Recommendations for replication of rainwater harvesting

From this study, the socio-economic and environmental advantages of rainwater harvesting have been identifi ed. Rainwater harvesting increases food and water security. Therefore, it is worth replicating elsewhere, the experiences of successful rainwater harvesting from Lare division. Recommendations made here are based on the experience of Lare farmers as gathered during the fi eld survey. These recommendations are:

36


1. Advocacy: There is a need to advocate for more adoption of RWH both at the policy and local level. Thus

there is need to clearly mainstream RWH in the water act. At local level, there is need for the various government agencies to promote RWH. Advocacy should be consistent and persistent as in the case of Lare, where an NGO, ICRA from the Netherlands spent over two years promoting rainwater harvesting. It was fi nally successfully accepted and adopted by the local people.

2. Collaborations. There is need for a cooperative effort among governmental agencies, as well as with private partners,

in pursuit of common goals. Such collaboration can range from very informal, ad hoc activities to more planned, organized and formalized ways of working together. In Lare, the authors were informed that in addition to the strong advocacy by ICRA, there was strong collaboration between the government agencies, research institutions such as Egerton University and private institutions.

3. Improved rainwater harvesting system design. There is a need to improve on the RWH system and document it for future use. Based on the Lare

experience, there are some hindrances to adoption of rainwater harvesting. These include high seepage rate, tank sizing, cost of constructing tanks and ponds, and excessive evapotranspiration losses. Failures of some rainwater harvesting systems discourage further adoption in the neighbourhood. Success of the design will hasten adoption by slow-adopters in the locality. There is need to introduce cheap means of reducing seepage and evaporation losses. For example, use of polythene sheets to reduce seepage. The key informants said that there was need to plant trees, which provide shade and reduce wind infl uence thus reduce these losses. Therefore appropriate agroforestry trees should be identifi ed, which have direct economic benefi t to the farmers.

4. Improved economic activities. To justify the associated work and overhead cost in adopting rainwater harvesting, farm returns need

to be increased. This would involve improving the crops grown and the market for their products. More farmers should be encouraged to produce crops whose harvest can be sold to the nearby canning factory. This would make rainwater harvesting more attractive and hence a widespread adoption would be observed.

5. Technical documentation: There is need for a technical manual on various aspects of rainwater harvesting. This should

highlight on technical designs, advantages and past experience of successful adopters. This could be distributed as a farmer’s manual.

6. Exchange visit: More exchange visits should be organised to and from Lare to share experiences on the use of ponds

as rainwater harvesting interventions that improve farm income, food and water security.

7. Record keeping Lare division farmers should also be encouraged to keep proper records of their farm output. This

will make it possible to quantify the economic advantage of RWH. Records will provide evidence of the advantages of rainwater harvesting.


37

References

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Calder, I. R. (1992). Hydrologic effects of land-use change, Editor in Chief D.R. Maidment. Handbook of Hydrology 13.1–13.50.

Di Gregorio A. (2005) Land cover classifi cation system (LCCS) Version 2: Classifi cation concepts and user manual. FAO, ROME.

International Livestock Research Institute (ILRI) accessed at www.ilri.cgiar.org/gid on Jan 2006.

Jaetzold, R and H. Schmidt (1983). Farm management handbook of Kenya. Natural conditions and farm management information. West Kenya. MOA. Nairobi. Kenya.

Krhoda, G. O. (1988). The Impact of Resource Utilization on the Hydrology of the Mau Hills in Kenya. Mountain Research and Development 8:193-200. Cited in Linking farmer, forest and watershed: Understanding forestry and soil resource management along the upper Njoro River, Kenya Timothy J. Krupnik University of California, Davis. USA.

Krupnik T. J. (2004): Linking farmer, forest and watershed: Understanding forestry and soil resource management along the upper Njoro River, Kenya. University of California, Davis. USA.

Mati B. (2004): Bright Spots on Technology-Driven Change inSmallholder Irrigation: Case Studies from Kenya. Paper presented at the NEPAD/IGAD regional conference “Agricultural Successes in the Greater Horn of Africa. IWMI Nairobi.

Migwi P. K., P. O. Gamba and T. A. Onyango. (2006). Participatory on-farm technology transfer for increased livestock productivity in sub-Saharan Africa, A case study of Lare division in Nakuru district, Kenya. Accessed at http://www.fao.org/DOCREP/ARTICLE/AGRIPPA/569_TOC_EN.HTM on 1st February 2006.

Sombroek, W.G.; Braun, H.M.H.; Van Der Pouw, B.J.A. (1982). Exploratory soil map and agro-climatic zone map of Kenya, 1980: scale 1:1,000,000. Kenya Soil Survey, Exploratory Soil Survey Report no. el. Nairobi, Kenya.

TWDB (2005): The Texas Manual on Rainwater Harvesting. Austin, Texas Water Development Board (TWDB), Texas, USA

ILRI GIS data. www.ilri.cgiar.org/gis

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Annexes

Annex 1: Log sheet for ground truthing

Trend analysis, Ground truthing and synthesis of land use data for Lare division in Nakuru district

Ground truthing formVillage………………………………….. GPS positionSub-location….………………………… E……………… S………………Location………………………………...

Land cover on the Map (approximately 100 m *100 m)…………………………………………………………...................................…………………………………………………………...................................…………………………………………………………...................................…………………………………………………………...................................…………………………………………………………...................................…………………………………………………………...................................…………………………………………………………...................................

Difference if any……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................……………………………...........................

Land cover on the ground (Approximately 100 m *100 m)…………………………………………………………...................................…………………………………………………………...................................…………………………………………………………...................................…………………………………………………………...................................…………………………………………………………...................................…………………………………………………………...................................…………………………………………………………...................................

Comments ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………


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Annex 2: Field Questionnaire

This survey aims at establishing the impacts of land cover changes on hydrologic regime of Lare division and how these impacts have contributed to the widespread adoption of rainwater harvesting in Lare division, Nakuru district.

Name of Interviewer ……..…………………… Sheet No:…. Date………………

1. Background information of the RespondentAge

Male/female Occupation

Sub-location

Division

Family size

Date of settlement

2. Land use/land cover informationWhat are some of the prevailing land use/land cover in the sub-location?………………………………………………………………………………………………............................................................………………………………………………………………………………………………............................................................

When and what are some of the past land use/land cover changes in this sub-location? ………………………………………………………………………………………………............................................................………………………………………………………………………………………………............................................................………………………………………………………………………………………………............................................................

What are the reasons for the land-use/land cover changes?………………………………………………………………………………………………............................................................………………………………………………………………………………………………............................................................………………………………………………………………………………………………............................................................

3. Impact of Rainwater harvesting System of rainwater harvesting adopted? (Include a photo and mark its corresponding questionnaire number in the map)………………………………………………………………………………………………............................................................………………………………………………………………………………………………............................................................GPS position …………………………E …………………………S

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Uses of water Method of harvesting Approx. quantity Is it suffi cient inQuantity Quality

DrinkingLivestockCrops

Others

Is it communal or individual initiatives? (If communal state the organization of the members)……………………………………………………………………………………………….......................................................………………………………………………………………………………………………....................................................………………………………………………………………………………………………….......................................................

Farm output(s) Amount before adoptingRainwater harvesting

Amount after adopting rainwater harvesting

Approx value

Any other advantages/limitations of the adopted rainwater harvesting techniques?……………………………………………………………………………………………….......................................................……………………………………………………………………………………………….......................................................……………………………………………………………………………………………….......................................................……………………………………………………………………………………………….......................................................

Are there emerging social roles related to Rainwater harvesting……………………………………………………………………………………………….......................................................……………………………………………………………………………………………….......................................................

How can we replicate these rainwater harvesting techniques elsewhere?……………………………………………………………………………………………….......................................................……………………………………………………………………………………………….......................................................

Why have some people not adopted the rainwater harvesting?……………………………………………………………………………………………….......................................................……………………………………………………………………………………………….......................................................……………………………………………………………………………………………….......................................................……………………………………………………………………………………………….......................................................


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Annex 3: Key informants

Name Village Location Occupation1. 1

James Ngugi MoA Naishi Division crop offi cer

2. Kamau Kuria Nganoini Naishi Farmer

3. Lucy Kimani Block II Naishi Farmer

4. Muchiri Farmer

5. Mwangi Farmer

6. Daniel Nyagah Sinendet Pwani Farmer

7. Karanja Mwangi Mtakatifu Clara Agricultural Centre

Agriculture coordinator

8. Stanley Rimungi MoA Divisional Soil Conservation offi cer

Annex 4: Percentage of land cover.

Land cover1973 1986 2003Hectares % Area Hectares % Area Hectares % Area

Bare land 314.2 0.3 505.7 0.5 463.9 0.4Cropland 24285.0 22.1 46069.4 41.9 74568.4 67.7Forest 39710.4 36.1 25031.0 22.7 13522.8 12.3Grassland 17481.4 15.9 14374.9 13.1 2594.2 2.4Settlement 3959.6 3.6 4547.2 4.1 7069.2 6.4Shrubland 19895.1 18.1 15792.3 14.3 8339.2 7.6Water 4364.4 4.0 3741.7 3.4 3539.4 3.2Total 110010.0 100.0 110062.1 100.0 110097.1 100.0

World Agroforestry Centre—Eastern and Central Africa’s Regional Land Management Unit (RELMA in ICRAF) ICRAF Building, Gigiri, P. O. Box 30677-00100, Nairobi, Kenya

Tel: (+254 20) 722 4000, Fax: (+254 20) 722 4001, E-mail: [email protected] www.searnet.org

www.worldagroforestry.org

ISBN 92 9059 197 8

The Swedish International Development Cooperation Agency (Sida) has supported rural development programmes in eastern Africa since the 1960s. Through its Regional Land Management Unit (RELMA-in-ICRAF) Sida promotes initiatives to strengthen the role

of small-scale land users in order to enhance food security and reduce poverty. RELMA-in-ICRAF is based at the World Agroforestry Centre in Nairobi and operates mainly in six eastern and southern African countries: Eritrea, Ethiopia, Kenya, Tanzania, Uganda and Zambia. RELMA-in-ICRAF’s goal in the region is to improve livelihoods of small-scale land users and enhance food security for all households. In pursuit of this goal, RELMA-in-ICRAF promotes environmentally sustainable, socially and economically viable farming and marketing systems, and supports policies that favour small-scale land users. RELMA-in-ICRAF organizes, on a regional level, training courses, workshops and study tours. It also gives technical advice, facilitates exchange of expertise and produces information material for the dissemination of new knowledge, techniques and approaches. A variety of reports, handbooks, posters and other information materials are published and distributed in the region on a non-profit making basis.

About this bookLand cover changes affect the hydrologic regime of an area, manifested at different spatial and temporal scales. This book highlights results of a technical study commissioned by RELMA-in-ICRAF focussing on the relationship between landuse and the local hydrology. Field surveys and Quickbird images were used to establish the impact of landuse and landcover changes in Lare Division of Nakuru District in Kenya and how these have contributed to the adoption of rainwater harvesting mainly using ponds. It has also dwelt at length on the technical and socio-economic aspects of the runoff harevsting ponds. It is hoped that experiences learnt from here can be applied in areas of similar agro-ecological zones within the Eastern and Southern Africa region.

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