Water we doing?

Posted on May 21st, 2019


In 2018 HYT built 33 ISSB water tanks in schools across Uganda, with a total capacity of 650,000 litres. Access to stored rainwater increase the time students spend learning in the classroom, by removing the need to fetch water from boreholes – an endeavour involving heavy jerrycans and multiple kilometre journeys.

Primary school children posing in front of a brand new ISSB water tank.

Plastic water tanks

Most water tanks in Uganda are made of plastic, and although they are easy to install, they do suffer from some key flaws. The main issue with plastic tanks is their longevity, damage is easily done to the main body and is difficult and expensive to repair. Unfortunately most of the damage is caused by people vandalising the tanks, often using knives or screwdrivers to pierce the tank.

A typical plastic tank found in many Ugandan schools.

Another disadvantage with using plastic water tanks is the transport costs and associated environmental impact. The vehicles used to transport a tank to its destination will produce pollution and increase the carbon footprint of the tank.

ISSB water tanks


Affordable, durable and environmentally friendly. The ISSB water tank is probably HYT’s most competitive product.

HYT builds water tanks out of ISSBs, this produces strong and durable structures. As the tanks are made from compressed blocks that are very difficult to pierce or damage, and can easily be repaired with some mortar. Additionally, since the blocks are produced on site, the transport costs are minimised, further reducing the environmental impact of tank construction.

A team of HYT masons can build two water tanks a month, with each tank taking a total of two weeks to complete.

As the water tanks are cylindrical, HYT uses curved blocks created with a different press. Construction begins with the foundation of the tank, this consists of a shallow circular trench in which a four-block high ring is built. This ring is then filled with concrete to form a flat base for the tank. At this stage a hose pipe is put through the base, this is used to filter out sediment which drifts to the base of the tank, ensuring the water provided is clean.

HYT masons use a wooden plank to flatten the concrete on the foundation of a tank.

Now the main body of the tank is built. The main cylinder consists of 16 slightly smaller rings of blocks. Unlike regular ISSB buildings, water tanks require mortar between each of the blocks to ensure the tank is watertight.

Once the main body of the tank is completed, wire mesh is attached to the outside and inside of the cylinder. The purpose of this mesh is twofold: it increases the durability and strength of the blocks in addition to providing a surface for the plaster to adhere to. Next the inside of the tank is plastered with a mix of mortar and a waterproofing agent. Then small rocks and mortar are used to make a bowl-like shape in the base of the tank. This is done to reduce the pressure around the rim of the base, as the weight of water in a full tank is 20,000 kilograms.

The bowl-like shape around the rim of a tank, made from small rocks and mortar.

At this point the tank is almost complete, a hole is drilled in the front to fit the tap and a roof is added and connected to gutters on the building. Finally the tank is plastered and painted, and the HYT masons will move onto their next project.

Rainwater harvesting Projects
HYT rainwater harvesting tank addresses multiple SDG’s

Keep up-to-date with HYT’s work by following us on FacebookTwitter and Instagram.

Winners of the Ashden International Award for Sustainable Buildings 2017.

Watch our exciting video, or check out our work at hytuganda.com

An Eye Opening Visit to World’s Second Largest Refugee Settlement: Bidi Bidi

Posted on March 6th, 2019


HYT has taken the exciting first steps West of the Nile to work in the world’s second largest refugee settlement: Bidi Bidi. The settlement is home to 750,000 South Sudanese refugees making it Uganda’s, unofficial, second largest city.

Bidi Bidi, located in Uganda’s extreme North West, has spectacular semi-arid landscape.

Yumbe Town, an NGO Epicentre

Yumbe town, previously a small, rural trading centre is now a hive of NGO activity at the heart of the settlement. Large UN trucks kick up the dust while electrical generators buzz constantly to compensate for the lack of a central grid.

The settlement resembles and operates much like many rural towns in Uganda.

The difference in landscape and climate between Jinja, HYT’s base in the South-East, and the extreme North-West is drastic. It is late February, Bidi Bidi has gone four months without rain and the temperature regularly exceeds 40oC.

The environment is unable to sustain the massive population of refugees. Monthly food packages arrive from the World Food Programme.

A UN-NGO Government

The massive influx of people in 2016 initiated an immense international effort to meet the needs of the men, women and children who were forced to flee their homes. Spearheaded by the UN, who are supported by a multitude of organisations, the settlement has left the emergency phase and entered recovery. The UNHCR (UN refugee agency) have a monumental task of managing the effort to ensure refugees are accommodated for according to the Sphere Humanitarian standards.

The UN Refugee Agency branded tarpaulins are very common in the area, a constant reminder of the humanitarian crisis still ongoing.

Under the guidance and management of the UNHCR, NGO’s form consortiums to tackle each sector of development: Livelihoods, Shelter, Food, WASH, education and protection. Each consortium is lead by a nominal NGO.

HYT’s arrival was timely, finding an environmentally friendly alternative to the burnt brick is a hot topic amongst NGO’s involved in construction.

HYT was delighted to attend the monthly meeting for the shelter department and the Zone 3 partner meeting, both lead by the UNHCR. It soon became apparent that the big players in construction were very serious about understanding ISSB and incorporating it into their plans.

The HYT team soon found excellent marrum deep in the heart of the settlement.

Devastating Deforestation

The humanitarian crisis has taken its toll on the environment. The tree population has been decimated for cooking and construction. A recent environmental impact assessment conducted in Imvepi refugee settlement found that 80-90% of firewood is used for brick burning, it has reached such extreme levels that the office of the Prime Minister is considering banning NGO’s and contractors from buying burnt bricks.

We counted 119 brick burning kilns during a 20 minute drive from Yumbe to Zone 3, Bidi Bidi.

It is no longer just environmentally conscious individuals or organisations applying pressure on NGO’s and contractors to find an alternative to the burnt brick; the environment itself is applying pressure: there simply are not enough trees.

Mango trees are some of the only species that live to maturity thanks to their high yields.

Firewood is imported from far flung regions as there are not enough trees in Bidi Bidi to keep up with demand. Meanwhile, frequent conflicts occur over the few remaining trees between refugee and host communities. The deforestation leaves the semi-arid region vulnerable to climate change, soil degradation and desertification.

The skills passed on to HYT graduates are more valuable than ever as influential players wake up to the need for sustainable construction.

It is a very exciting time to working with ISSB, HYT with its 12 years of experience is looking to lead the movement away from burnt bricks and transform Uganda’s construction industry.

Keep up-to-date with HYT’s work by following us on FacebookTwitter and Instagram.

Winners of the Ashden International Award for Sustainable Buildings 2017.

Watch our exciting video, or check out our work at hytuganda.com