Investigation towards alternative water resources Mtwara, Tanzania

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Investigation Towards

Alternative Water Resources

Mtwara, Tanzania

An investigation by:

Mattijn van Hoek

Student Land & Water Management

(International Water Management)

Waterschap Velt & Vecht

AMREF Flying Doctors

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Investigation towards alternative water resources in Mtwara, Tanzania

AMREF Flying Doctors / Waterschap Velt & Vecht 2

Investigation towards alternative water resources in Mtwara, Tanzania

Hoek van, M., (August 2010). Investigation Towards Alternative Water Resources in Mtwara, Tanzania. Coevorden, The Netherlands. Waterschap Velt en Vecht

This report is written as a study towards alternative water resources next to the actual used methods. The results should be read as an advise.

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Preface

I would like to use this opportunity to thank Hermen Klomp and Pieter Filius of the Regional water authority Velt en Vecht located in Coevorden, the Netherlands. They have coordinated and advised me by providing technical input for my graduation study at AMREF Mtwara (Tanzania). Furthermore, I would like to thank Joris van Oppenraaij from AMREF Netherland. His advices, critics and experiences were helpful for me. As well as the advises from Mark Rietveld and Dick Bouwman from Aqua for All. Their expertise in hydrogeology has been helpful. From Hogeschool van Hall – Larenstein, I would like to thank my teacher and coordinator Henk van Hoof. His support, enthusiasm and commitment to his job is an example for many.

Moreover, I would like to thank Ignatio Kagonji, project manager AMREF Mtwara (Tanzania) by advising me in executing the field visits and in controlling the scope of work. As well as Emmanuel Fungo, project officer AMREF Mtwara (Tanzania) who has attended me with all the field visits and by sharing a room in his house for giving me an unforgettable experience in the warm and friendly surrounding of Mtwara town.

And of course I would like to thank the other staff of AMREF, namely Said, Lwanji, Lawrence, Ligaga who warmly welcomed me in Mtwara and facilitated me with never ending enthusiasm.

Also I would like to thank all the local residents of Mtwara rural, who took their time to answer the questions and discuss the matters of access to safe and reliable water sources.

To my parents, August 2010 Mattijn van Hoek

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1

Introduction

1.1 Background

The government of Tanzania declares in the national water policy that ‘the availability of water is a basic need and entitled to everyone’. Based on findings of AMREF, the estimation of disease burden related due to the lack of safe drinking water and adequate sanitation in Tanzania is 70%. To improve the water supply in the district, the African Medical, Research Foundation (AMREF) Tanzania and the Mtwara Rural District Council has started the WATSAN project in 2008. This project is about water, hygiene, and sanitation. AMREF hopes to finish this project in collaboration with water board Velt en Vecht (by providing technical assistance and function as co-financier) in 2011.

The project aims to improve the health and quality of life of selected marginalized communities of Mtwara district. Including 6 wards and 40 villages. This is done by increasing access to- and sustainable use of safe water and basic sanitation services by constructing boreholes in each village.

1.2 Objectives of the study

This study outlines a study towards more sustainable water sources in Mtwara region, Tanzania, according to the Tanzania national water policy. The purpose of the investigation is to provide technical evidence for an addendum towards the European Union (main financier in this project) for adjustment of the scope towards development of alternative water sources.

This study, as defined in the Terms of Reference (appendix 1) has the following objectives:

1. Exploring the possibilities of alternative water sources (apart from deep boreholes)

2. Standardize collected data in database formats and train the local staff where needed

Ad1. The objective is to investigate possible alternative drinking water sources in the villages of phase three and other villages out of the project area. This possibility arises by the release of budget by reducing the number of boreholes from 51 to 40. Those, potential, alternative solutions will possibly offer the population a more reliable and affordable access to safe drinking water. Key

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elements for analysing alternative water resources are affordability, technical usability, and durability. The result is a method, which is based on these key elements.

Ad2. Setting up of a proper data management system will be done for water source monitoring, both qualitative and quantitative. With adequate monitoring, it is possible to intervene in time when recharge of a water source is insufficient or contamination takes place. The local staffs receive training in adequate monitoring and the use of databases in ArcGIS.

1.3 Methodology

The approach of this investigation is based on a participatory approach that involve community members, village and sub village governments and committees. The methods used to gather and analyse information include desk studies, data collection, field visits and different analyses. The investigation is started with the desk study and data collection. Together with the fields visit it is possible to analyse the objectives of the study. In appendix 2 is found the plan of approach for this investigation. Apart from the study there will take place a training in GIS and data management (the trained elements can be found in appendix 9)

1.4 Structure of this Report

The report focuses on the actual used water resources and the possible alternatives. For this, the study area will be discussed in chapter 2, the description of the study area. Thereafter, in chapter 3 the methods are discussed to come up with the result and findings in chapter 4. This chapter starts with presenting the actual approach towards water collecting and the finish with suitable alternatives which are analysed by different points, like the sustainability, performance and costs. Chapter 5 is the conclusion and the report finish with the discussion in chapter 6.

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Ruvuma River. The north part of Chawi is flowing to the small rivers that are flowing directly to the Indian Ocean in the north east of Mtwara region. The north part of Mtiniko, Nitekela and almost whole Njengwa (except a small part in the north west) and the south east part of Mnima are flowing into the valley which is going north where it combines with the catchment of the north west of Mnima and the slice of Njengwa.

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3

Methods

Different methods are used to get the findings as presented in the results. The methods used are discussed in the same order as the results are presented in chapter 4.

3.1 Actual ways for collecting water

The used methods for funding the results for the actual approach to collect water is done including, interviewees and field observations during field visits.

The interviewees find place after there is made an appointment with the representative person of each visited village. The representative person can be the village officer, the village chairman of the pump operator. If necessary, the representative person ask nearby villagers for help.

In this survey, the field observations are as well from importance to find out the actual ways for collecting water. The field observations are done by visiting the villages by car and visiting the local used water systems by walking.

3.2 Comparison of alternatives

A desk-study is conducted to obtain a comprehensive overview of possible alternative methods for the collection and the storage of rainwater. In this desk-study there is done a review of published literature on the subject covering local and foreign sources. By using the results (positive successes) of applied systems elsewhere in the world, it is possible to do evaluate the feasibility for this region.

The evaluation of the feasibility is done by analysing the alternatives to two aspects, namely ‘geomorphology and hydrogeology’ and the ‘Tanzanian water policy’. The evaluation is done together with the employees of AMREF.

3.3 Village meetings

In the village meetings the used methods are in detail presented in the strategy village meetings, appendix 5. The method of a village meeting is used to assess the possibility for alternative water collection methods within the study area and assess the demand of alternative water collection methods within the study area. The approach of the village meetings can be summarised as follow:

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The first subject is to let the villagers think about any possible alternatives. It is a brainstorm activity whereby the villagers needs to mention any, according to them, suitable alternative.

Thereafter the suitable alternatives, based on the desk-study, are presented with the local villagers. In this presentation the alternatives are explained by making use of pictures and schematic overviews.

After summarize the mentioned alternatives by the villagers and the presented alternatives all alternatives are discussed once more towards the feasibility according the villagers.

3.4 Rainfall analysis

Methods which are used to analyse the precipitation data are mentioned as follow: the mean annual precipitation and the ranked annual precipitation gives insight in the average precipitation for the project area over the period of records. By ranking the annual precipitation the extreme highs and low annual precipitation are identified easily, as well as the ranger of average and average minus the standard deviation.

Thereafter the pattern analysis is done by analysing the variation of the annual precipitation around longer-term mean precipitation and the moving mean.

The variation of the annual precipitation around longer-term mean precipitation makes it possible to identity patterns of wet and dry years. The moving mean dampens the year-to-year fluctuations and the extreme values. This presents a smoother curve to show the general stream flow pattern.

With the rainfall analysis the different minimum annual repetition times needs to be calculated so they can be used as input for the performance calculations.

3.5 Constructing and drilling of boreholes

To find out the overview of the different elements in the system of constructing boreholes there has are executed interviewees with pump operators, AMREF employees. For receiving a comprehensive overview of the system, several field visits have find place to find out by personal field observations the exact elements in the system.

It is important to obtain a comprehensive overview of the different elements in the system to be able to decide the costs and to find out the probable bottlenecks.

3.6 Alternatives

Different methods are used for the calculations for analysing the alternatives. The following aspects will be used as method for analysing the different alternatives:

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 Technical usability  Sustainability  Water quality

 Performance and cost analyse.

The last bullet, performance and cost analyse needs more explanation, for this the methods of the performance and cost analyse are discussed as well.

3.6.1 Performance and cost analyse

The calculations are done, by making use of the constructed models where different parameters are included. The underneath mentioned parameters are explained in detail in appendix 10, where the calculations of the models are discussed.

 Three different annual precipitation levels;  Three different demand levels;

 Number of users

 Surface type of catchment area;  Variation in size of storage facility;  Efficiency of storage of water;  Efficiency of fetching of water;  Price for a of bucket of water

For analysing the performance of the different systems, different indicators are used. The different measurements provide information for different stakeholders who will be connected to the system. In the following paragraphs the performance of each indicator will be discussed.

Demand satisfaction

The demand satisfaction is measured in percentages by dividing the amount of water that is annual delivered to the water user and the annual demand of the water user.

This is the fraction of the annual demand that the system manages to deliver. In other words, it gives an answer to the question ‘how well the water system performs’. The demand satisfaction is of special interest to the householder. (T.H. Thomas, D.B. Martinson, Roofwater harvesting). By calculating the demand satisfaction, it is first needed to calculate the annual amount that is delivered. This is done by removing the annual overflow of the annual runoff (see formula 3.1).

The annual runoff will be that part of the amount of water that falls on the prepared surface and will be stored by the storage facility. Some of the precipitation will get lost by evaporation, infiltration or will be lost in the sand filter etc. The annual overflow is the amount of water that cannot be stored and will leave the storage facility through an escape or overflow structure. The storage facility can be a tank, reservoir, soil body etc.

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The annual water that is delivered is calculated as follows:

By knowing the amount of water that is annually delivered into the water storage, it is possible to calculate demand satisfaction. This is done by dividing the annual amount of water that is delivered to the annual amount of water that will be used by the local households, the demand (formula 3.2).

%

Efficiency

The efficiency is the fraction of the rainfall on the catchment area that can be used by the water user. It is the amount of water that is delivered to the water user in relation to the annual amount of water that is falling in the catchment area. The efficiency is of interest to the designer of the system. First the annual amount of water that is delivered is calculated by making use of formula 3.1 and the efficiency is thereafter calculated by using formula 3.3.

%

Reliability of supply

Another measurement for receiving an answer on the question ‘How well does the water system perform’ is by calculating the reliability of supply. The reliability of supply provides an overview in percentages as to how many days of a year the water storage facility runs dry. It is the percentages of days whereby the storage facility contains water.

Payback time

The payback time is an indicator tool to analyse the amount of time which is needed to payback the construction costs. This can be of interest to the funder. It is based on the cost price of water for a 20-liter bucket, the annual water demand of the water user(s) and the construction costs of the system. It is calculated in formula 3.4:

Knowing the annual value of water is it possible to calculate to payback time in months (see formula 3.5):

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Formula 3.2

Formula 3.3

Formula 3.4

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Equivalent unit cost (for every water user)

By calculating the costs per litre for a storage tank it is possible to compare different storage. A more accurate way to compare the costs of different storage tanks is by making use of the equivalent unit cost. It scales down the particular system to the capacity of 1m³. It is calculated by dividing the costs of the water storage facility by the square root of the volume of the storage facility, as shown in formula 3.6. In other words it is the costs for every cubic metre.

A small addition can be made to calculate as well the costs for each cubic metre/water user. This is done by dividing the equivalent unit cost by the number of water users that are using the system (formula 3.7).

/ /

Budget

By taking the depreciation of the different components into account and by adding the operation and maintenance it is useful to calculate the cost for each month to be able to operate and maintain the system. Based on a fluctuating usage of the systems where it is needed to pay for money the average use of monthly water consumed for the system is calculated (see appendix 13). Based on this number it is possible to calculate the costs of each cubic metre water which is consumed. When this amount is known it is also possible to compare it with the actual price of bucket (20-litres). Because the water users pay for water there is an average monthly income and because of the depreciation of the components and the operation and maintenance of the system there are also monthly costs. By comparing the income and the costs there arise an insight if the system is profitable.

Formula 3.6

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which are f following res ng water is a gs in chapter pter 4.3 wh d in chapter d whereby th h an overvie

r

he project a phs. on the plat an 500 metre n the dry se shallow wells , at the botto s. The wate ur and some own an unp r, most of the there are po figure 4.2), th s as well a d and the dry

anzania & Vecht 2 found by sults are analysed 4.2. The here the r 4.4. In heses are ew of the area. The eau, the es, which ason the s takes 1 om of the er quality e water is protected e springs onds and he ponds place for y season 20

(22)

Figure 4. The swam nearby th Figure 4.3 The floodp River, nea Bandariar 2 mps in the valle he village Ngoro 3 plains of the Ru arby the village rusha) In is slo swam on th these

4.1.3

Villag use t drinki Band locate River will c villag

4.1.4

Peop water the v villag far fro a dep (17-4 divert the u small The occur tanks conta area ey ongoro. uvuma nvestigation t owly enterin mps contain w ese swamps e swamps, si

Ruvuma

ges nearby t the river (se ing water. ( dariarusha) A

ed further aw r. For the villa cost 8 hours e executive

Stored w

ple who have r for a longe illages. Som es contain s om any othe pth of 2.4 me 45 cubic me ted toward th npaved walk l flows to a s catchment a rs, as well as s were full o amination tak (date observ towards alter AMRE g, different water for a l s and ponds

nce the near

a River

the Ruvuma ee figure 4.3

Per.Comm. At the end

way from the agers of Mal s for a roun officer, Mala

water in gr

e the ability er time. The me villages do everal groun r water sour etres (8ft). Th etre). The st he ground ta king pads on ubsurface re area is unpr s losses by h of water and kes place a ved: 06-05-20 rnative water EF Flying Doc swamps ar onger period s. People of rby located w River, like 3) for washin Ismael A M of the dry e Ruvuma R amba, fetch ndtrip. (Per.C amba).

round tanks

to purchase availability o o not have a nd tanks, esp rce. The tank he diameter d treams that ank. Normally n small slope eservoir, a ca rotected, so high infiltratio d intensely nd there are 010) r resources in ctors / Water re running o d water. The surrounding water source Ngorongoro ng, fishing a Mkoba, villa season also River come t ing of water Comm. Twa

s in the vill

e a hand dug of ground tan any ground w pecially Mala ks that have differs in a ra are formed y the small f es in the villa atchment are contaminat on into the sa used by vil e many loss n Mtwara, Ta

rschap Velt &

out of water re is a high villages opt is dried up. and Banda s well as so ge executive o villages w to fetch wat at the Ruvum alib Faraji C

lages

g reservoir c nks is divers water tanks a mba which is been visited ange of 3 to by heavy r flow is makin age. By leadi ea is created tion of the r andy soil. Th lagers, even ses in the ca anzania & Vecht 2 r. A few pressure t to go to ariarusha, ource for e officer, which are er at the ma water Chinanda, can store e among and other s located d all have 5 metres rains are ng use of ng those . rainwater he visited n though atchment 21

(23)

Figure 4.4 Reservoir water from the surfac filling the is constru in. A smal give acce Figure 4. Drinking p tap is lock unlocked 4 r in Malamba, w m two roofs and ce are collected tank. A fence o ucted to prevent

ll door, in the fro ss to the water

5

points in Maranj ked and one is d. In They cover const Spora show estab

4.1.5

In Ba Japan Band const not ha In the harve the d water water

4.1.6

With side small goats perso huma In the store 200S 1000 is 50 where d from d for f wood t falling ont, nje. One nvestigation t fetch the w r are constru tructed to pro adically roof wn in figure 4 blished under

Buying w

andariarusha n Internatio dariarusha is tructed in 20 ad any break e wet seaso est rainwater dry season h r is even so r cost €1,45.

Water fr

the construc of the road l ponds durin s), infiltrated onal observa an consumpt e dry season water can s SH (€ 0,12) i SH (€ 0,58) SH (€ 0.03, towards alter AMRE water by mak ucted on the otect the chil water harve 4.4. The gutt r a small slop

water from

a and Maran onal Coope s constructed 002. The bore kdowns till no n, the boreh r and fetch w however, the ld in the sur In figure 4.5

rom Roads

ction of new . The small ng rain. Here or evaporat ation it is no tion. n arises wate sell the wate in the rainy at the end o March 2010 rnative water EF Flying Doc king use of a e tank. Arou dren from fa esting takes

ters are mad pe towards t

m boreholes

nje is still a w ration Agen d in 2000 a ehole in Mar ow. hole is norma water of near villagers ma rrounding vil 5 there is sho

s

roads, draina drainage ca e it is stored ted. By the ot known wh er scarcity. F er. For a buc season, for of the dry se 0). People w r resources in ctors / Water a bucket on nd the tanks alling into the

place. A no de of GI she he ground re

s

working bore ncy (JICA). and the bor ranje has, un

ally not funct rby unprotec ake use of t lages. Norm own a drinkin age canals a anals collect until it is us staff of AMR ether the wa

For the peop cket of 20 lit

some villag ason. The c who cannot

n Mtwara, Ta

rschap Velt &

a rope. Nor s a fence of reservoir. oteworthy ex eets or PVC eservoir. ehole, funde . The bore rehole in Ma nlike other bo tioning. The cted shallow the borehole mally one cub

ng point. are made in t the precip sed by cattle REF and on ater is also

ple who were tres people es (Malamb current value afford this o anzania & Vecht 2 rmally no f wood is xample is C and are ed by the ehole in aranje is oreholes, villagers wells. In e and the bic metre the bank itation to e (namely basis of used for e able to pay from a), up to of water offer their 22

(24)

labour for cultivating land in exchange for water. (Per.Comm. Nuran Issa Liyumba, pump operator, Malamba)

4.2 Comparison of alternatives

The desktop study is done according to a funnel-model. The scope started as broad as possible without excluding any alternative. After this the possibilities were filtered according to parameters (like topography, geology, rainfall) which are representative for the project area. Out of the new list, the technical staff of AMREF selects three alternatives, next to the actual method of drilling deep boreholes. Those three alternatives will be tested at the phase III villages of the project area. Three alternatives will be discussed in respect to:

 Affordability  Technical usability  Sustainability/durability  Considerations

The not selected alternatives can be found in appendix 4. The selection is based on two criteria. The criteria of the methods are the geomorphology and hydrogeology of the area and the Tanzanian water policy, which prescribes are drinking point between 500 metres from each household. The selected methods, meet the demand of the Tanzanian water policy. (The goal of the project of the AMREF boreholes is also reducing the distance for water fetching). The selected methods meet also the second criteria of the geomorphologic and hydro geologic characteristics of the area (as discussed in chapter 2.2)

Method Geomorphology and hydrogeology Tanzanian water policy (<500 metres) Flooding technique with ditch pattern

Unsuitable Unsuitable

Contour bending Unsuitable Suitable Infiltration with percolation tank Unsuitable Unsuitable Roof water harvesting Suitable Suitable

Recharge pit/shafts Suitable Unsuitable Small earthen dam Unsuitable Unsuitable

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Surface water harvesting for subsurface soil storage

Suitable Suitable

Rock catchment Unsuitable Not applicable Surface water

harvesting with reservoir

Suitable Suitable

Water pyramids Suitable Unsuitable

4.3 Village meetings

Seven villages out of 13 of the third phase of the AMREF project have been visited. The strategy of the village meetings and minutes of each meeting can be found in appendix 7 & 8. The village consultation consists of questions whereby the villages need to think about the case when there is no water available. Which possibility do they know or, in their opinion, may be possible in this area. After that the possible alternatives are explained and the villages may give a reaction on the feasibility of the alternatives. The following general results came out of the discussions:

I. The people in the village are aware of the risks of fetching water at unprotected water sources.

II. All people give utmost priority to a reliable water supply nearby the villages.

III. For the possible alternatives (in comparison to the deep boreholes), a difference needs to be made according to the location of the villages. The villages that are located near the Ruvuma River are positioned in low-lying areas. All the other villages in the project phase are located at elevated areas, on the Ruvuma plateau.

The view of the villagers according to the village meetings on reliable water supply in the village are:

I. A reliable water supply with fetching point nearby the village (in each sub village one drinking point)

II. For creating an impervious layer for storage facilities only concrete is seen as possible.

III. For storage pots, with a maximum size of 100 litres, Masasi-clay may be suitable.

Table 4.1

Overview of possible alternatives, according to the desk study. On base of the criteria is made a selection of three suitable methods for this area.

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4.3.1 Possible alternatives according to villages

Low lying villages

One village is located in the low-lying areas nearby the Ruvuma River. The possible alternatives are:

 Protected shallow wells  Rain water harvesting by

o Roof water harvesting o Hard surface water harvesting

Elevated villages

The possible alternatives mentioned in the villages, which are located on the plateau, differ. The mentioned possibilities are less. Protected shallow wells are not suitable and trials of placing protected shallow wells (by Finnwater) have not been successful (Ngorongoro). Rainwater harvesting is seen as the suitable solution, but adequate storage is lacking. In one village (Maranje) the annual amount of rainfall is considered as not sufficient for being a reliable source of water for the whole village (the explanation of the rainfall analyses that the annual rainfall is sufficient for the whole village was ignored).

Furthermore, the villagers who are living on the plateau come up with possibilities to improve the water storage in the valleys. One of the possibilities is constructing a, so-called, Lambo (in some villages called Rambo). A basin of concrete is constructed in the bottom of the valley. Hereby it is possible to collect water from the surrounding hills. Locations of these Lambo are unknown.

The construction of protected shallow wells in the valley is mentioned as well. In Nachume there have been several attempts to dig a shallow well, but all the times the shallow well is collapsed by the recharge of groundwater. A protected shallow well made of concrete rings is seen as the solution.

4.3.2 Opinions about presented alternatives

All the alternative possibilities are seen as suitable and normally the people prefer both the deep borehole and the alternatives.

In Bandariarusha, the first priority is given to the borehole and then to alternatives. Maranje

(Owners of a working borehole) are putting question marks by the annual amount of rainfall and if this can be sufficient for providing water whole-year-round for all the villagers. Besides, their own water supply, they prefer another borehole, so they will have the possibility to sell more water to people from other villages.

During the dry period all the villages, except Marnaje, are facing problems with scarcity. Maranje is the only village with a working deep borehole.

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Figure 4.6 An overvi meetings. follows: lis and the p by the vill the possib discussion alternative The pictur meeting in Malamba (bottom-le (bottom-ri 6 iew of different v . The strategy is stening to the d ossibilities prop lagers. Explana ble alternatives n about the pos es.

res shows the v n Nachume (top (top-right), Mar eft) and Ngoron

ight) In This rainw seen The receiv harve a cer infiltra lead t Roof Howe villag as roo An im differe In und villag The t areas has b altern The c close villag syste active is me village s as demand posed tion of and a ssible village p-left), ranje gro nvestigation t borehole is c water harvest as a problem alternative ving possible esting. The ra rtain depth ated rainwat the water to water harv ever, this ca e, as there a of. mpression of ent village m derneath tab es and the m table is divide s and that are been a discus natives accor conclusion of e as possible e. The ment ems in the reg

e or inactive entioned seve towards alter AMRE constructed b ting is seen m in Malamb whereby ra e attention. ainwater is le is placed a er. By makin a well. vesting is s annot be con

are not suffic

f the village meetings are ble 4.2 is give mentioned po ed by the vill e located at ssion about t rding to the v f the demand to the village ioned possib gion. Some o system is kn eral times bu rnative water EF Flying Doc by JICA in 2 as an esse ba and Nachu inwater is u The alternat ead to an inf n imperviou ng use of a een as a p nsidered as cient househ meetings ca shown. en an overvie ossible altern ages, which the elevated the demands villagers. ds for a villag e. If possible ble alternativ of the possib nown in the a ut the people r resources in ctors / Water 002. To tack ntial solution ume. used and s tive is based filtration field us layer to a drainage sys possibility fo a source of holds with ga an be seen in ew of the de natives. are located areas. In ea s of the villag ge is a reliab e, a drinking es are all ba bilities are me area. The lam e spoken to, h

n Mtwara, Ta

rschap Velt &

kle the water n. Lack of st stored in the d hard surfa where it is s avoid leakin stem it is po or local hou f water for th alvanized iro n figure 4.6, mands of the in the low-ly ach village m ges and the p

ble water sup point in each sed on used entioned but mbo, for exam

have never s anzania & Vecht 2 scarcity, torage is e soil is ce water stored. At g of the ossible to useholds. he whole on sheets where 4 e visited ing meeting possible pply as h sub d no mple, it seen it. 26

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Village Demands Mentioned possible

alternatives Low lying villages

Bandariarusha Reliable water supply in

each sub village. Deep Borehole Shallow wells

Big roof for surface water harvesting

Elevated villages Maranje Another borehole with

drinking points in every sub village

-

Malamba High need for water. Roundtrip in dry period is up to 8 hours per day per household.

There is a unique place for a ‘lambo’ (8km of the village)

Replacing of the broken submersible pump of the JICA borehole.

Water harvesting (roof & surface)

Mtopwa Clean water without iron Shallow wells in the valleys.

Mkahara Concrete rings to prevent collapsing their dug shallow well.

Water supply before the drilled AMREF borehole.

Big tanks by big roofs, for rainwater harvesting

Ngorongoro A reliable water supply nearby the village. The fetching time is in the dry period 4 hours for a roundtrip.

Construction of shallow wells in the valleys. Construction of ‘lambos´ in the valleys

Use of roof water harvesting

Collect water from small streams nearby village during wet period. Nachume Storage facilities for

collecting rainwater. Filtering of dirty surface water.

Improve unprotected shallow wells in the valleys.

A ‘lambo’, which is constructed in the valley Table 4.2

The table shows an overview of the visited villages with their demands and mentioned possible alternatives. A division is made with low-lying villages and elevated villages.

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4.4 Rainfall analysis

Rainfall data is obtained from weather station Naliendele Agromet, prepared by S.B. Pallangyo. The data covers a period of more than 14 years, from January 1995 to March 2010. Naliendele Agromet is located in the project area and with a radius of 30 km it covers the whole project area. It is assumed that in this area the deviation of the precipitation data is insignificant and for that reason the data of this weather station is representative for the whole area.

In figure 4.7 is shown a comparison with the FAO data (see chapter 2.3). The FAO data shows the same patron of line, but gives some small differences in the months February and March. In those two months the precipitation is, respectively 36 and 46 mm less by comparing it with the precipitation of weather station Naliendele. The used precipitation data for the calculations in this study are based on the weather station Naliendele,

By ranking the annual precipitation and plotting the average within one standard deviation the annual precipitation that have occurred about 68% of the time, by a normal probability distribution. By calculating the probability of occurrence for each year, it is found that the lowest value between one standard deviation (the year 2007) is equivalent with a probability of 80%. This means that the annual precipitation of the year 2007 occurs in 8 out of 10 years and for this the repetition time is 1 in 5 years. For these reasons, priority is given to the precipitation of 2007 by the calculations in this study.

0 50 100 150 200 250 January Febr uar y Ma rc h Apr il Ma y

June July August Se

pt em b e r Oc to be r Nov em b er Decem b er mm/month

Comparison precipitation data from FAO &

Naliendele weather station

Prcipt FAO (mm) Prcipt Naliendele (mm) Figure 4.7

Graph with the comparison the precipitation of the FAO data (see chapter 2.3) with the data of the Naliendele weather station. In the months February and March the differences of the precipitation are, respectively 36 and 46 mm.

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Figure 4.8 Graph of annual ra and 2009 average a lines are standard plus stand 8 the distribution ainfall between 1 9. The red line is and the small gr the average min deviation and a dard deviation. In In fig precip devia Mean period precip differs the m From decre By ta precip annua 4 1 1 14 1 1 P reci p it at io n (mm) of the 1997 s the reen nus average nvestigation t gure 4.8 is pitation that ation. The pro

n annual pre d of interes pitation by t s from 567 m mean annua m 2002 to 20 easing by tim aking the 5-y pitation rema al peeks are 0 200 400 600 800 000 200 400 600 800 2004 2002

Ranked

one

Prcpt. towards alter AMRE seen that t t falls in th obability for t ecipitation is st; it is obt the number mm in 2003 t al precipitatio 009 there ari me. year moving ains betwee replaced by 2002 2006 2008 2000

Annual Pre

standard d

Average rnative water EF Flying Doc the year 20 he range of this year is 8 the averag tained by d of months a to 1619 mm on is slowly ses a saw p average it is n 80 and 10 y a smoother 2000 2001 1997 1999

ecipitation,

deviation (N

Average r resources in ctors / Water 07 is the y f average m 80%. e precipitatio ividing the a year. The in 2004. In f increasing patron, with s found that 00mm and th r constant tre 1999 1998 1996 1995

orange ma

Naliendele s

‐ Stdev / Ave n Mtwara, Ta

rschap Velt &

year with the minus one on for the m sum of all annual pre figure 4.9 is s from 1995 high and low

the average hat the high end line. 1995 2007 2009 2005

rk for range

station)

rage + Stdev anzania & Vecht 2 e lowest standard multi-year monthly cipitation seen that to 2001. w peeks, e monthly and low 2005 2003

e

29

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The annual variations are analysed, so the next focus will be on the monthly variations. In figure 4.10 the average monthly precipitation and the precipitation of 2007 is plotted. By taking a two year period the wet period comes up well in the period from September until May, whereby it is split if only one year is taken (on the left and right side of the graph).

By analysing the mean monthly precipitation, it is shown that there is one dry period and one wet period. The dry period starts in May and goes up to October, the wet period is from November to April. The top of the wet-period is in March followed by lower peeks in February and January. The top in March is around 213mm and in June, the precipitation is only 5mm. The overall precipitation for a year with reliability of 50% is 1063mm. By analysing the precipitation of 2007 there are a few differences compared to the average. The dry period lasts one month longer and is from May until December. In the wet period, the precipitation is more concentrated in the months February and April. With a significant lower amount in precipitation in December and January, (less than 50% compared to the average). The overall precipitation for the year 2007 is 797mm. That is a difference of 266mm compared to the mean annual precipitation.

For different reasons the precipitation data of the year 2007 is taken as standard for further calculations in this study: The calculated repetition time of the minimum annual precipitation is 1 in 5 years. The rainfall intensity is not gradual over the whole year round, but 53% of the annual precipitation falls in two months (February and April). The storage facilities need to be dimensioned in a way that enough water can be stored to overcome seven months of dryness.

40 56 72 88 104 120 136 19 95 1996 1997 1998 1999 2000 2001 0220 2003 2004 2005 2006 2007 2008 2009 Prec ip it at io n (mm)

Variation of Annual Precipitation Around Longer‐

term Mean Precipitation for Period of Record + 5‐

Year Moving average for Mean annual precipitation

Mean annual precipitation Mean precipitation for period of record (88.39mm) 5‐Year Mov. Avg. (Mean annual precipitation) Figure 4.9

Mean Annual Precipitation. In blue is plotted the average precipitation over the years 1995 to 2009. In red is plotted the average over the period of record and in green is plotted the 5-year moving average. The high and low peeks from the mean annual precipitation are faded in a smoother trend by visualising a 5-year moving average.

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Figure 4. Two curv period of and obtai the dry en column si monthly p column sh of the yea period for precipitat the wet p concentra 10

ves are plotted o two years to vis in a better overv n wet period. Th ignifies the mea precipitation the hows the precip ar 2007. The we r the mean mon tion is smooth w eriod of 1007 is ated on a few m In Chara      1 1 2 2 Pr ecipi ta tion (mm) over a sualize view of he blue an e red pitation et nthly whereby s months nvestigation t acteristics fo Repetition Dry perio Wet perio Overall p 53% of th April. 0 50 100 150 200 250 Ja n u ar y Fe b ruary _Marc h

Mont

towards alter AMRE or the year 20 n time is 1 in d is 7 month od is 5 month recipitation o he annual ra Ap ri l Ma y June July Au gu st

hly Precipit

Mean month Precipitation rnative water EF Flying Doc 007: n 5 years hs hs, of 797.3mm ain falls in tw Au gu st September Oc to be r Nov em b er De cem b er

tation (for p

ly Precipitatio of 2007 (relia r resources in ctors / Water wo months, n Ja n u ar y Fe b ruary _Marc h Ap ri l Ma y

period of tw

on (reliability o ability of 80%) n Mtwara, Ta

rschap Velt &

namely Febr y June July Au gu st September Oc to be r

wo years)

of 50%) anzania & Vecht 3 uary and Oc to be r Nov em b er De cem b er 31

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Table 4.3 Descriptio different c constructin Figure 4.1 Overview boreholes the boreho panels. Th tot the ele where it is different d on and costs of t components for ing a borehole. 11 of the system o s. On the left sid ole with the sola he water is pum evated tank from s distributed to drinking points. In

4.5

The a tanks water 4.11 If the reliab show Desc Wate Distri Cons Pump Solar Subm Total In tab seen €11.1 €9.88 €30.0 water the of de is ar mped m nvestigation t

Constru

actual approa s. The water r tank the w is shown an system is w bility of suppl wn in table 4.2 cription of C er storage tan bution netwo struction of bo p house r panels mersible pum l ble 4.3 the co in figure 4 119. In the b 81 and the en 000 and have r tank of 50 towards alter AMRE

ucting an

ach is the dr r tanks have water is distr overview of well maintaine ly are 100% 2. Components nk (50m³) ork orehole mp osts of the d 4.11. The d borehole is p nergy is com e a deprecia m³ and cos rnative water EF Flying Doc

nd drillin

illing and con e the capacit ributed to dif the system ed the dema . The total co s Cos different com rilling and c placed a sub ming from the ation of 20 ye t €16.352 fr r resources in ctors / Water

ng of bor

nstruction of ty of 50 cub fferent drinki nd satisfactio osts of the d sts in Euro 16.352,00 13.081,00 11.119,00 5.000,00 30.000,00 9.811,00 85.363,00 ponents are construction bmersible pu e solar panel ears. The wa rom where it n Mtwara, Ta

rschap Velt &

reholes

boreholes a bic metres. F ing points. on, efficiency different elem Costs in 28.1 22.5 19.1 8.6 51.6 16.8 146.9 shown whic of a boreh ump. This pu s. Solar pan ater is pumpe t is distribut anzania & Vecht 3 and water From the In figure y and the ments are in Shilling 58.144,00 525.482,00 46.918,00 610.000,00 660.000,00 894.542,00 95.086,00 ch can be hole cost ump cost els costs ed to the ed by to 32

(34)

different drinking points. This distribution network cost €13.081, which include all the pipes and taps.

By taking into account the depreciation of each component and assuming that the labour price is included in the price of the investments the total cost/month is €442,11, table 4.3. Including the operation and maintenance the total cost for each month is €662.11.

Based on the average monthly cubic metre water consumed, the price per cubic metre water should be € 1.84. (total budget in appendix 13). At the moment the actual price for one cubic metre water is €1.45 (see chapter 4.1)

Calculation of costs per month and per m³ consumed

Cost/month Price per m³ (€)

Investments (include labour costs) 442,11 1,23 Operation and Maintenance

- Maintenance and repair 100,00 0,28

- Salary 120,00 0,33

Total 662,11 1,84

The total costs for each month are 662,11 and based on the average monthly consumption of water the monthly income for the system is 521,94. This means that there is a monthly loss of 140,17, as can be seen in table 4.5.

Monthly income (€) 521,94 Monthly costs (€) 662,11 Difference income and costs (€) - 140,17

4.6 Alternative 1. Surface water harvesting with

subsurface storage

This method is based on a possibility found in a study for rain water harvesting in Sri Lanka. In this study, it is mentioned: “A cheaper catchment surface can be made by laying a piece of plastic sheeting in a shallow excavated and levelled area”.

The water storage capacity draining capacity of coarse sandy soil is 34%, this result in volumetric moisture storage of 340 Litres for every cubic Table 4.4

Overview of the calculations of the monthly costs and the price for one cubic meter.

Table 4.5

Overview of the monthly income and costs. It can be seen that this alternative is not profitable.

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Figure 4. Schemati 1. The w soil and drains it shallow w 12 ic sketch of alte water is stored d by making is lead to a pr well In metre IRC. Sanit On th and i humu depth precip down precip to the them period I. II. Pond for th The u    

4.6.1

Show time price, relate and d ernative d in the use of rotected nvestigation t e. (Water Ha - The Ha tation Centre he bases of f in the village us and on the h of the laye pitation will npour almos pitation that e valleys. Th more suitab d for two rea Due to th recharge Clayish s is possib certain le ds and swam ree to four m use of coarse Infiltration evaporati The soil i a filter No mosq Process o

Affordab

wn undernea consuming. , based on t ed durability. durability. towards alter AMRE arvesting. A gue, The N e, 1992) field observa es are very e places in t r of humus i infiltrate qui st no wate drops at the he top soil in ble for agricu asons: he hills aroun

by seepage soil has a hig ble to retain vel. mps are forme months into th e sandy soil n rate is h ion is able to rem uito breeding of mineralisa

bility

th are the e The costs o the selection The materia rnative water EF Flying Doc Guide for P Netherlands; ations can be sandy. On the village w s only one t ickly at the er pools or hillsides wil n the valleys ulture. The v nd the valley of the infiltra gher moistur the ground ed in the rain he dry period as storage fa high what r move small c g, by absenc ation improve lements for t of the placem n of material als in this stu

r resources in ctors / Water Planners and IRC Inter e concluded many place here there is o two decim plateaus. D r ponds oc l partly infiltr s contains m valleys conta ys this result ated precipita re supplying dwater for a ny season th d.

acility has dif results in a contaminatio ce of stagnat es water qua the costs. P ment of poin l. The mater udy are base

n Mtwara, Ta

rschap Velt &

d Project Ma national Wa

that the soil s, there is t s little agricu metre. As a re

irectly after ccur. Howe rate and part more clay an ain water for

in a longer ation.

capacity, w longer peri

hat can conta

fferent advan a minimum ons because ed surface w lity oint I and V nt II - IV can rials corresp ed on cost, av anzania & Vecht 3 anagers / ater and s around totally no lture, the esult, the a heavy ver, the tly run off

d makes a longer period of whereby it iod on a ain water ntages. loss to it act as water are very n vary in ond to a vailability 34

Investigation towards alternative water resources Mtwara, Tanzania