Sand dam’s contribution to year-round water supply

This year we are celebrating 30 years since the Rural Water Supply Network was formally founded. From very technical beginnings as a group of (mostly male) experts – the Handpump Technology Network – we have evolved to be a diverse and vibrant network of over 13,000 people and 100 organisations working on a wide range of topics. Along the way, we have earned a reputation for impartiality, and become a global convener in the rural water sector.

RWSN would not be what it is today without the contributions and tireless efforts of many our members, organisations and people. As part of RWSN’s 30th anniversary celebration, we are running a blog series on rwsn.blog, inviting our friends and experts in the sector to share their thoughts and experiences in the rural water sector.

This is a blog post from RWSN Member Hannah Ritchie, based in the United Kingdom

In 2020, I joined forces with Sand Dams Worldwide (SDW) to help them answer the question of “how long water from sand dams is lasting throughout the year”. In this short blog post, I am happy to discuss with you our findings and the implications of this study. We’ll be discussing “why we are interested in this question”, “how we researched this question”, and “what we found out”.

Firstly though, for those of you not familiar with what a sand dam is, I would like to direct you here for a video, which explains them better than I could, and here to SDW’s website where you can find everything sand dam related you might need to know.

Why are we interested (and why you should be too)?

So, why do we care about whether sand dams are providing water year-round? There is uncertainty over whether water from sand dams is lasting all the way through the dry season, or whether people can only abstract water from sand dams at the beginning of the dry season, when they have just been replenished by the rains. Because of this conflict in results, we can’t easily conclude how effective sand dams are as a dryland and specifically dry season water source. For example, can people rely on them when other water sources are unavailable (such as when surface waters have run dry)? Or are the dams dry by the second week of the dry season? Answering this question is very important for understanding their level of use, acceptance, and financial viability, helping to inform future water management interventions and to ensure that communities are serviced with a continuous improved supply. Knowing whether there are certain dry season months when sand dams have no water being abstracted can also inform on months when water supply from other sources needs expanding. Finally, knowing which sand dams have more or less water being abstracted can aid in optimising sand dam design.

You might be thinking, “but no water abstracted doesn’t necessarily mean no water being available”, and you would be right. Because, whilst abstraction volumes may be linked to storage, many other variables, such as convenience, quality, and the use of other sources can also impact abstraction. Thus, the contribution that sand dams make to water security is not synonymous with the amount of water actually stored in the dam. Therefore, whilst this study can show us abstraction patterns from sand dams and therefore behaviours of use, it cannot confirm for certain whether there is or isn’t any water available.

How did we do it?

Now you know why we’re interested and why it matters, how did we actually go about answering the question: “how long water from sand dams is lasting throughout the year”? In 2019, 26 sand dam hand pumps in Makueni and Machakos Counties, Kenya were fitted with Waterpoint Data Transmitters (WDT) by ASDF. These devices measure the number of times and with what force a handpump is used over an hour and convert this into an estimated volume of water abstracted (Thomson et al., 2012). This data point is then transmitted by SMS. I had access to this remotely sensed data from April 2019 until October 2021. With a data point every hour for 26 sites over 31 months, I ended up with a very large data set!

Alongside this abstraction data, I also had access to interview and observation data provided by MSc student Joanna Chan, ASDF, and SDW. These variables included perceived salinity, abstraction limits, livestock use, whether the dam is said to have ever run dry, presence of rainwater harvesting tanks, actual salinity (μs/cm), area of dam wall (m2), average distance travelled from home to dam (km), and user numbers (Chan, 2019).

This data was then analysed to assess how much water people were abstracting and for how long throughout the year the water continued to be abstracted for. The variables collected from interview and observation were then analysed to provide insight into differences in abstraction between sites. For example, did sites with larger dam walls have more water being abstracted, or did salinity impact abstraction in any way?

Finally, we looked specifically at the last week in September (as a proxy for the end of the long dry season) to assess whether enough water to specifically meet drinking water needs (2 L/p/day) was still being abstracted at any sites. Due to the necessity of an improved source of water for drinking (of which a handpump is one), we wanted to know whether the handpumps could independently meet drinking water needs, in case no other water sources were available.

What did we find out? 

After analysing all of the data and wrapping my head around some statistical analysis, I like to think that we found some interesting results.

The most obvious finding was that of high variability in abstraction volume between the 26 hand pumps and seasons. We found abstraction to be significantly higher in the long dry season, indicating a high reliance and delivery of water when other sources are compromised. The diagram below shows median monthly abstraction (L/month) (red line) and average monthly rainfall (mm) (brown bars – dry season and blue bars rainy season) across all sites – indicating higher abstraction when rainfall is lower.

There was abstraction data available from 21 handpumps (81%) by the end of at least one of the analysed long dry seasons, with at least some water still being abstracted. At 59.1% of these sites, enough water to meet each user’s drinking water needs (2 L/p/day) was being abstracted in at least one of the analysed years. This indicates that such dams can meet the drinking water needs of users independently of other sources.

Using the variables which were collected in interviews and observations, we found that sites with a greater proportion of people using the water for livestock, higher salinity, and larger dam walls had significantly higher levels of abstraction. This is to be expected as higher salinity sites are often used more for livestock (Chan, 2019), which have a greater water demand than that for drinking, whilst larger dam walls can lead to a greater volume of sand build up and therefore water storage (Maddrell & Neal, 2012). 

These results highlight sand dams as a sustainable alternative to other dry season sources such as water vendors, which can be expensive and unreliable. However, lower abstraction in certain months and sites highlights that we must approach water management holistically. No one technique is necessarily the answer to dryland water security and all available water sources must be considered. Clearly, not all sand dams behave the same, with certain sand dams always likely to have higher levels of abstraction than others. However, high abstraction and sustained water availability by the end of the long dry season at many sites profess the positive contribution that sand dams can make to a community’s water supply, offering opportunities for further success in the future.

Closing remarks

I really hope you enjoyed learning about abstraction trends from sand dams as much as I enjoyed studying them (most of the time!) If you’re interested in learning more, I hope the paper will be published soon, which will be freely available for everyone to read. If you’d like to reach out, my email is hannah.ritchie@cranfield.ac.uk. Many thanks for reading.

A bit about the author

I am a PhD student at Cranfield University. I began my PhD in September 2019 in WaSH with the CDT Water WISER. With a background in geology and environmental engineering, I wanted to design my PhD project around earth sciences and development. This was how I ended up finding sand dams and partnering with SDW and Africa Sand Dam Foundation (ASDF).

Outside of work I love to run, hike (generally be outdoors as much as possible), read, and am learning French. I am very passionate about science communication and firmly believe that research results need to be translated into accessible formats for all to read and understand, hence why I have written this blog post for you (definitely shorter, more fun, and less boring than reading a 15-page paper!)

Did you enjoy this blog? Would you like to share your perspective on the rural water sector or your story as a rural water professional? We are inviting all RWSN Members to contribute to this 30th anniversary blog series. The best blogs will be selected for publication. Please see the blog guidelines here and contact us (ruralwater[at]skat.ch) for more information. You are also welcome to support RWSN’s work through our online donation facility. Thank you for your support.

Photo credits: Hannah Ritchie

References

Chan, J. (2019). Abstraction of Water from Sand Dams in Machakos and Makueni Counties (Kenya) via Handpumps.

Maddrell, S., & Neal, I. (2012). Sand Dams: a Practical Guide.

Thomson, P., Hope, R., & Foster, T. (2012). GSM-enabled remote monitoring of rural handpumps: A proof-of-concept study. Journal of Hydroinformatics, 14(4), 829–839. https://doi.org/10.2166/hydro.2012.183

RWSN at the UNC Water and Health Conference: Where Science Meets Policy

The Water and Health Conference: Where Science Meets Policy, organized by the Water Institute at the University of North Carolina (UNC), is one of the most important conferences for WaSH professionals. This year the conference has not only explored the interactions between drinking water supply, sanitation, hygiene, water resources and public health, but put also a strong emphasis on rural water supply in developing countries. Researchers, practitioners and policy-makers had the chance to present and lively debate

by Sandra Fuerst and Sean Furey (Skat Foundation)

The Water and Health Conference: Where Science Meets Policy, organized by the Water Institute at the University of North Carolina (UNC), is one of the most important conferences for WaSH professionals. This year the conference has not only explored the interactions between drinking water supply, sanitation, hygiene, water resources and public health, but put also a strong emphasis on rural water supply in developing countries. Researchers, practitioners and policy-makers had the chance to present and lively debate on following topics:

  • Measuring Progress Toward Sustainable Development Goal (SDG) Targets
  • Water Scarcity
  • Rural Water Supply
  • WaSH Equity and Inclusion
  • WaSH in Emergencies

At this year’s conference, the RWSN and its partners have convened two side events, providing water professionals an interactive space for engaging on cutting-edge topics of rural water supply. These sessions translated the “virtual RWSN DGroups into real life discussion groups” as Stef Smits (IRC), the chair of the first side event, phrased it. The participating water experts shared their experiences and developed exciting ideas with their peers for challenging rural water contexts.

Universal and Sustainable Rural Water Services: Different Perspectives, Common Goals

In the first side event, participants were invited to understand two major concepts to apply them later through group discussions in a case study of an WaSH implementation organisation, HYSAWA, Bangladesh, presented by their Managing Director, Md. Nural Osman.

Md. Nurul Osman (HYSAWA)

Sara Ahrari presented the NGO perspective of how organisations, like Simavi, use monitoring and data systems to promote Social Accountability and the holding duty-bearers to account when it comes to the Human Rights to Water and Sanitation. Miguel Vargas-Ramirez from the World Bank and Ellen Greggio from WaterAid presented then the development partner perspective on how data and monitoring can be used to raise the capacity of governments and service providers to deliver sustainable rural WaSH services, particularly rural water supply. This included on-going work to develop benchmarks for rural water service delivery, which WaterAid is testing in Myanmar.

After the break, Elisabeth Liddle from Cambridge University, and Prof. Rob Hope from Oxford University, gave the research perspective on how data and monitoring is enabling them to generate deeper insights into why rural water supply systems fail and how to develop new ways of making them more sustainable.

After the concepts have been introduced, the participants applied them in smaller groups to the HYSAWA case study in Bangladesh. This case study was presented by HYSAWA (Hygiene, Sanitation and Water Supply) to come up with suggestions and advice on how his organisation can improve the quality and sustainability of their rural WaSH interventions. The audience debated questions around:

  • Who is responsible for monitoring and data collection? Who is accountable and feels responsible for what? Those who design the system?
  • Who is responsible for the service provision of water in rural areas? And who needs to be hold accountable for that?
  • What are the drivers to feeling responsible?
  • What are the services that needs to be done?
  • How do the processes need to be managed?

Stef Smits (IRC)

Stef Smits summarised the debates during this session on three levels:

Who? The answer that communities and local governments should be accountable for the service provision of water in rural areas seemed to be too easy as in fact it is not clear at all. The role of service providers in many contexts is not very well defined, also not in legal terms. Accountability is often spread over several layers. For example, minor operation and maintenance (O&M) services can be done on community level, while major O&M services can be provided through public services. Then the levels of accountability also need to be differentiated between service provider and service authority. This first differentiation will help to define who is responsible for what and will help the service authority to hold the service provider accountable. As soon as the roles of different stakeholders are clearly defined, it can be defined more specifically who needs to collect the data. The collection of data then needs to be spread over different levels, from household, community, service provider to authority level.

What? The debate started around the functionality of rural water supply devices and has shown that there is not a simple answer of ‘yes’ or ‘no’ to functionality. Functionality needs to be distinguished between functional devices and functional services (i.e. O&M services). This led to the question how functionality should be measured and which other indicators should be taken into account. Should we bring water quality in as an indicator? Clearly, financial indicators are necessary. As the trend to use indicators and monitoring tools is increasing among service providers and governments in rural areas, it becomes increasingly necessary to define clear indicators for universal rural water services. Based on that development, we can start to understand rural water as a systemic issue.

How? The identified need to define clear indicators on different levels, raised the question of how the process of developing monitoring and evaluation (M&E) systems should be managed. Even though governments were identified to lead this process, NGOs could support to trigger it. However, if a NGO has developed a working M&E systems, it cannot be simply handed over from a NGO to the government, without a well-planned transition phase. It also needs to be taken into account who “the government” is and on which level the government operates. Data and M&E systems will at the end always need a sector development approach.

Pipe Dream or Possible: Reaching the Furthest Behind First in the WASH Sector? – RWSN Side Event 2

The second side event was convened by RWSN (Simavi, Wateraid) with London School of Hygiene & Tropical Medicine and World Vision. During this session, the participants developed human-centred solutions for “Reaching the Furthest Behind First” and “Leaving No One Behind” in the WASH sector.

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The participants worked in several groups on different case studies of extremely vulnerable people (i.e. disabled pregnant child) that are exposed to extreme hazards in their environment (i.e. arsenic contamination of groundwater).

In several steps, the participants developed possible solutions based on their field of expertise: In a first step, they illustrated the social, cultural, physical, political and legal barriers that the imaginary persona faced, regarding their social inclusion. Then they created inspirational ideas of possible solutions to these barriers. The different options were heavily discussed before choosing one or more solutions. To illustrate the actions and stakeholders needed to implement these solutions, a story board was created by each group. Finally, the persona, storyboard and possible solution were presented in pitches to all participants.

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The two side events have been great examples of how the RWSN works as its best: “Taking concrete examples and bring them together with key concepts from research and practice. This is the richness that RWSN provides: Linking practical questions with conceptional frameworks (Stef Smits)”.

Sharing experiences of data flows in water and sanitation – some reflections from AGUASAN Workshop 2018

A perspective on the 2018 AGUASAN Workshop: “Leveraging the data revolution Informed decision-making for better water and sanitation management” June 25th to 29th 2018, Spiez, Switzerland

AGUASAN Workshop: “Leveraging the data revolution Informed decision-making for better water and sanitation management” June 25th to 29th 2018, Spiez, Switzerland 

Update 24/08/2018: Read the AGUASAN event report

AGUASAN is the Swiss Community of Practice for water and sanitation that has been running since 1984 and comprises regular meetings through the year and an annual week-long workshop focused on a specific topic, which this year was around role of data in decision-making in water and sanitation services. Around 40 participants attended at a really great training facility in Spiez, in central Switzerland. They came, not just from Swiss organisations, but from a wide range of partners (many who are active RWSN members). There were participants from Bangladesh, Tajikistan, Mozambique, Peru, Thailand, Mali, Pakistan, Benin, Egypt, Mongolia, the UK, South Africa, US and many more.

The structure of the event mixed up presentations with “Clinical Cases” group work focused on real-world case studies and challenges where participants could advise representatives from those organisations:

Different aspects issues around data use in water and sanitation were introduced through a good range of engaging presentations:

AGUASAN workshops aim to come out with useful output and what was proposed was a practical guideline that pulled together they key points from the presentations and discussions, around a common framework, which was beautifully illustrated on the wall of the plenary room at the end:

 

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Preliminary result of the AGUASAN workshop: the “Navigator manual” (click/tap to expand) designed by Filippo Buzzini (Sketchy Solutions)

 

I was not completely convinced by the linear conceptual framework that was proposed because what I have observed previously, and came out in the discussion and presentations, is that WASH systems are generally messy, non-linear processes. However, what was clear is that good quality monitoring, mapping and data is a critical “fuel” for driving positive feedback loops for short-term operational decision-making and longer term learning and adaptation cycles.

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A not-so-pretty graphical summary by your correspondent (click/tap to expand).

Despite Skat’s long association with the AGUASAN workshop this was my first workshop and I enjoyed it, and found it useful to have the opportunity to have a few days away from the distractions of emails, to focus on one topic with knowledgeable colleagues from all over the world and all over the WASH sector. The field trips also took us to explore some of Switzerland fascinating water history and modern challenges.

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Your correspondent giving a lighthearted recap of key learning points (and Swiss World Cup win against Serbia) from Day 1 (Photo. J. HeeB)

Tandi Erlmann, Johannes Heeb and the Cewas team did a great job with the facilitation and event design and also thanks to SDC for their continued financial and thematic support to the event. As well as good for networking – it was also a good international crowd to be around with the World Cup going on!

The final report will be published on www.aguasan.ch where you can find outputs from previous workshops. Most of the presentations and background documents can be on the SDC ResEau website.  Photos from the event can be found here on Flickr.

Below are my sketch-notes of some of the presentations (click/tap to enlarge):

“Monitoring & Data for Rural Water Supplies” (click/tap to open PDF version)

 

Photos: Johannes Heeb (Cewas) – Main Image: group shot of workshop participants

You cannot manage what you do not measure; but should you measure what you cannot manage?

Countries have committed to reach SDG 6, providing universal access to their population with safely managed water supply services, with country specific targets. This is a process that governments, as duty bearers, need to manage. Therefore they also need to measure progress in that.
Continue reading “You cannot manage what you do not measure; but should you measure what you cannot manage?”

#RWSN @ #WWW : the presentations

RWSN co-convened two sessions at last week’s SIWI World Water Week in Stockholm and presentations are available to download:

WASHoholic Anonymous – Confessions of Failure and how to Reform

All presentations: http://programme.worldwaterweek.org/sites/default/files/panzerbeiter_lt_1400.pdf

Build and Run to Last: Advances in Rural Water Services

Continue reading “#RWSN @ #WWW : the presentations”

Sharing water point data is easier than ever using the new Water Point Data Exchange #WPDx platform

guest blog by Brian Banks, GWC

Over the past decade, a dramatic shift has taken place in the water sector that fundamentally changes the way that work is done. During this time, water point mapping around the world has accelerated at unprecedented rates. Dropping costs of technology and innovative software has enabled national governments, as well as funders, NGOs, academics, and others to inventory, share, and even monitor the work they have contributed to.

Continue reading “Sharing water point data is easier than ever using the new Water Point Data Exchange #WPDx platform”

Word from the Chair: The Challenge of Change

The world in which we work is changing.  Some changes may be sudden and catastrophic, for example the outbreak of armed conflict, or the impacts of flooding.  The wars in Sierra Leone, Liberia and Somalia have resulted in destruction of much water infrastructure.  The Pakistan floods of recent years have had similar disastrous results.  But many of the changes which are occurring are continuous, for example growth of population, economic growth, or climate change as a result of greenhouse gas emissions.  Some of these changes are quite fast while others are much slower.  In my own working lifetime I have seen populations grow by a factor of about 3 in many of the countries where I have worked.  Gradual and continuous change, but by now having massive impacts on the state of the environment and natural resources, and on demands for water.

Continue reading “Word from the Chair: The Challenge of Change”

Reflections from the Colorado WASH Symposium

by Jonathan Annis, WASHplus

I recently attended the Colorado Water, Sanitation and Hygiene Symposium, hosted by the University of Colorado Boulder. The two-day regional gathering, intended primarily for students, faculty and local WASH professionals within greater Denver WASH community, attracted 130 attendees. A closely knit and cross-disciplinary group of graduate students did a fantastic job planning and hosting the event.

For those who aren’t aware – this included me before arriving on campus – the Colorado WASH community is thriving. The Denver area is home to a blend of international NGO’s like Water for People and iDE as well as local non-profit groups with a regional or country focus like El Porvenir. Add to the mix the energy created by a dynamic group of graduate students and academics engaged in the international WASH sector and the stage was set for an engaging discussion.

I had two main takeaways from the event:
Continue reading “Reflections from the Colorado WASH Symposium”