SandDams4Life

About 80% of the land cover in the eastern province of Kenya is categorized as arid or semi-arid. The currently biting more frequent long droughts, thanks to climate change,  have left the region barren and with dry rocky riverbeds considering that this part of Kenya has recently experienced failed to highly suppressed rains in four consecutive years, which is historical. With almost a similar percentile (over 80%) of the residents of the same area residing in a rural setting/areas  and relying on rain-fed smallholder subsistence farming and livestock keeping for their survival, extreme poverty is becoming more alarming and famine even more frequent.

 This is the reality facing over 15 million people in a region that I was born and grew up in. The saddest thing to process is the fact that when eventually the erratic short intense rains strike after a long stretch of scorching and more frequent elongated droughts, the villages are literally swept away by flashfloods with extensive soil  erosion due to lack of vegetative cover. Most of the highly vulnerable un-baked clay mud-walled houses, which are very common in the area due to high poverty levels, houses are not spared too. Within two to four short weeks after the onset of the ever dwindling rainfall, all the water is gone and drains into the Indian Ocean leaving the poor villages at the mercy of another long cycle of devastating droughts. A few overseas charity organizations try to sparingly help a few of the affected communities but it boils down to too little too late. 

When i was contracted by one of the charity organizations to undertake research on how to impound riverbed water along the seasonal river channels in the region, I realized that a more sustainable and robust intention by these communities for the communities themselves was long overdue to supplement the insufficient support from the local government and charity organizations. This work would also turn out to be my research project area for my Master of Science in Geology degree that focused on water dams and geotechnical investigations for suitable sites location. After completing Masters Studies about a decade ago It dawned on me that as someone who hailed from the affected region I had to come up with a solution that is centered on the local people to address the problem outlined above.

That is how eventually after several years of soul-searching I founded a small business by the name Sand-Dams for Life. The idea was to implement my research findings as well as that of other researchers to address the challenge bedeviling the local communities. Basically since the entire region is underlain by granitic and metamorphic (largely gneissic) basement rocks with large quartz mineral grains, this area is bound to yield very well-sorted high quality sand deposits along the river channels that was just washing downstream to Indian ocean in business-as-usual scenario for centuries.

So my intervention was to work with local communities to construct sand dams along in the many naturally occurring streams and dry gulley’s crisscrossing the region. The reason is that if a natural barrier prevents the water from draining downstream, it is stored in the sand behind the barrier and below 50 cm water stored in the voids between the sand grains does not evaporate. Depending on the coarseness of the sand particles, up to 35-40% of the volume behind the dam can be water. The natural barriers are rock bars or undulations in the bedrock forming a natural dike. A sub-surface dam or a sand dam built on top of the dike enhances the natural barrier and increases the storage capacity. The water is then extracted with a shallow well behind the dam wall.

The site survey and design of the dam is critical for the dams to last through seasonal flash floods and for the reservoir to fill with coarse sand as opposed to silt and the my skills with that of a team I have trained come in handy. We work with the affected communities to construct these dams. We site, design and construct the dams for them without any upfront capital cost for them.

The community provides manual labour. We then agree once the dam sand deposit is mature, my organization can sustainably harvest the excess sand and monetize it to recover our cost plus a small profit and also cover the extra cost whereby we procure cement (from only cement-factories that offset their carbon footprints) for these communities to construct more resilient houses that cannot be swept away by flashfloods.

We target communities who are affected by the extreme droughts and are also unable to afford construction of resilient houses made of concrete and manually made and baked clay bricks.

An analysis of the impact of our work so far shows substantial financial benefits derived from the sand dam in addition to gains for the individual farmers and the communities around the dams in terms of quality of life. Attendance rate for children in school has doubled. Sicknesses has reduced and hygiene increased because of the clean water at close proximity to the homestead. Malnutrition is no longer an issue as every household is able to water a kitchen garden throughout the year. The ability to produce a high yield from irrigated farms with the option to sell excess has increased the families’ expendable income. Livestock is able to be kept and sold at a higher price. Families have more time to invest in their future and less stress about basic living amenities.

From an ecological perspective the sand dams are also very valuable as they recharge aquifers and rejuvenate the riverine ecology enabling increased vegetative cover and bio-diversity along the river.

I have put together culturally competent team that understands the area well considering that i was born and attended both my primary and secondary/high schooling in the same region grappling with the same challenges my team and i are tackling.

We use our scientific knowledge and technical expertise to site, design and construct the sand dams on their land alongside the beneficiaries.. We work with them from the inception, siting, design and construction phase. They provide free manual labour during the construction We also identify best clay site for them to make bricks manually and bake them then we provide cement from factories that use carbon capture and utilization to ensure the cement has least carbon foot print. We recover our cost when we sustainably harvest and monetize the excess sand from the reservoirs.

We have constructed with the affected communities about 60 Sand-Dams each serving about 20 households and each households (extended families) has an average of ten individuals. That translates into about 12,000, people impacted. Those affected by drought and famines, thanks to climate change are about 10 to 15 million people so there is a long way to go!

I strongly believe the tremendous convening power of the MIT Solve can help us connect with the right partners we need to collectively scale this intervention to impact and save more lives and livelihoods.