How much does a sand dam cost? Expand The cost of a sand dam can vary from around £25,000 to £40,000 depending on the size of the sand dam, and where it is being built. As sand dams require little to no maintenance, there is not really any cost associated with a sand dam after it has been constructed.
Who builds the sand dams? Expand For most of the areas we work in, it is the communities themselves that are responsible for the construction work. Our partners will provide skilled supervision and instruction, but the labour put towards sand dams comes from the communities. This aligns with one of our key values of providing communities with the tools to change their own lives, giving a hand up rather than a handout. In Lekurruki , northern Kenya, the community structure is very different to the other areas in which we work. As pastoralists, the Maasai there are semi-nomadic, moving with their herds. As such, we employ local labourers to help complete the sand dams. Click here to find out more about the impact of sand dam construction on local labourers. We do also run expeditions where you can get involved in constructing a sand dam. Read more about that here.
How long does it take to build a sand dam? Expand This varies considerably depending on local conditions, weather, and the size of the sand dam. However, most sand dams will take between one and two months to get from the start of excavation works to the completion of the sand dam.
Who owns the sand dam once it is built? Expand Once a sand dam is complete it is the community’s to own and look after. They are responsible for maintaining them and ensuring that the surrounding area is well looked after. Our partner organisations provide them with all the training that they need in order for this to happen, and for the sand dams to keep supporting the communities for many years.
How long does a sand dam last? Expand Sand dams last for upwards of 60 years (the oldest known in operation is 100 years old), and along with the virtually zero operation and maintenance costs, it makes them a remarkably low-cost, sustainable solution to water scarcity.
How much water can a sand dam hold? Expand Sand dams store up to 40 million litres of water which is enough to provide a year-round supply for over 1,000 people.
Can a sand dam be built anywhere? Expand There are three technical prerequisites for locating appropriate sand dam sites. Firstly, it needs to be built on a highly seasonal river (flowing for weeks rather than many months of the year). Secondly the river needs to have sufficiently sandy river sediment. Thirdly, there must be accessible bedrock to dig down into. And Excellent Development has established two golden rules for sand dam design. The first is that dams must be built on bedrock (or, in rare cases, impermeable, compacted sub-soil). Secondly, the dam must allow the river to flow as it did before. For more in-depth guidance on how to design and build sand dams, read our sand dam manual.
How is a sand dam different from a ‘normal’ dam? Expand A sand dam does not stop the flow of a river. They are designed to allow 97-99% of river water to continue downstream, by flowing over the dam. This means that downstream users are not affected. Sand dams are also different to standard dams in that they allow sand to build up behind the dam wall, so that water can be stored within it. This means that you can’t see the water being stored until you scoop into the sand, or pump it out using a shallow well. Storing water in sand like this keeps it safe from evaporation, contamination and disease.
If I want to build a sand dam in my country/region, what's the first thing I should do? Expand Every year we hold sand dam learning visits in southeast Kenya with our partners, Africa Sand Dam Foundation. If you'd like to learn about and see first-hand how sand dams work, please email [email protected] to find out more about a possible learning visit. You can also read our sand dam manual which will tell you everything you need to know about building a sand dam.
What other water solutions do you provide? Expand Where conditions are not right for a sand dam to succeed, or where another rainwater harvesting technology is more appropriate, relevant or could make an even greater impact, we can work together to support other water solutions such as school water tanks, rock catchments and sand dam road crossings. Click here to find out more.
How is a sand dam different from other rainwater harvesting methods? Expand Sand dams are one of the lowest cost rainwater harvesting techniques, costing less than both underground and above ground tanks per 1,000 litres of water provided. Costs are kept down by the fact that communities contribute to every sand dam project (e.g. by providing basic construction materials and labour), but also because sand dams require little to no maintenance, and have no operational costs.
Can I visit a sand dam/community or volunteer to work on one of your overseas projects? Expand Excellent organises annual sand dam expeditions that welcomes volunteers of all ages and abilities to visit a community in southeast Kenya and build a sand dam alongside them. Former sand dam expeditioners have called it a "life-changing experience". For more information including how to apply for the next expedition, visit our expeditions page. Aside from this, as Excellent has a strict Safeguarding Policy that seeks to protect and prevent harm to our beneficiaries (who often live in very private, remote and/or vulnerable areas), out of respect for the communities, we do not send volunteers to projects, nor can we provide the exact locations of where the communities live - and we do not encourage self-funded trips to our projects either. If you would like to see examples of our work, and hear from the communities, we do have many stories showing how sand dams and access to clean water has transformed lives around the world.
Why is it mostly women and children collecting water from the sand dams? Expand In many of the regions and communities we work with, families split the daily responsibilities. Traditionally, it is the men who earn the family’s income through going to work, whilst the women will collect water, stay at home, cook and look after the children. However, sand dams and subsequent climate-smart agriculture empower women, as they become decision makers and leaders in their communities, whilst children (and parents alike) have improved nutrition at school, work and home thanks to the safe water. The local source of water also vastly reduces the amount of time needed to collect water, giving more time and opportunity for women to develop their own income, and for children to go to school.
What is climate-smart agriculture and how does it fit in with your work with sand dams? Expand Sand dams provide lifelong access to water, but in order to support dryland communities to become truly self-sustainable, they may require further training in how to make adapt their farms and land to their climates and environment. That is where climate-smart agriculture comes in, which we provide alongside our partners. Climate-smart agriculture is environmentally sustainable farming practices that increase agricultural productivity and enable food security, whilst also allowing communities to adapt to, and mitigate, the effects of climate change. This helps communities to build their resilience to a changing climate. Techniques include growing drought-tolerant crops (such as sorghum, sweet potato and cowpeas), conserving seed, mixed cropping, manure use, crop rotation, early-planting, agro-forestry on farms and soil conservation measures such as terracing. Watch our films or read more about climate-smart agriculture for further information.