In the chaotic aftermath of the Tsunami, the Indonesia Government faced the challenge of housing tens of thousands of survivors - people who had lost everything but their lives to the waves. It swung into action, throwing up dozens of Temporary Living Centres, or TLCs, on vacant land throughout the province of Aceh. Locally they are known as barracks - rows of long wooden accommodation blocks resembling a military camp.
In Camp Raider, 4km outside the town of Banda Aceh, each barrack comprises of twelve tin-roofed rooms measuring 3 x 4 metres, raised up on stilts for protection against the torrential tropical rains. Communal porches run the length of each block providing shade and little extra space for drying clothes and storing the clutter of everyday life. In a humid climate, where temperatures can reach forty degrees, six people live and sleep in each room - it is a hot and cramped environment.
Five months on from the disaster, there's a gentle hum of domestic activity around Camp Raider as knots of women gossip on the porches, nursing babies, pealing vegetables or nurturing tiny flower gardens planted in the shade of the porches. But back in February, when Concern Worldwide first visited the camp, the scene was very different. Although basic shelter had been provided there was no infrastructure - pools of stagnant water, piles of garbage and overflowing latrines made it a miserable home for the 1,000 new residents. Critically there was no clean water and many were succumbing to skin diseases and diarrhoea.
"In the beginning everything was just thrown together and although I was sympathetic that things had been done in a hurry, the conditions were bad and there was a sense of urgency. We had a lot to do."
Karanja and a team of six local engineers set to work, prioritising the provision of potable water to the camp. Clean water was delivered by water-truck to fill a 10,000 litre tank whilst a deep, 92 metre bore hole was dug to reach an unpolluted local water source. Refuse bins were provided, drains installed and gravel laid on the pathways that criss-cross the camp. To dispose of the considerable amount of latrine waste and rubbish, a "honey wagon" and garbage truck were hired. Conditions in the barracks improved quickly but needed to be maintained. This task was assigned to four volunteers who were trained to spread the word amongst their neighbours about importance of keeping the environment clean.
One of Karanja's team is 24 year old Aldalina Anggraini. Last year she graduated with a degree in Civil Engineering and had planned a career in academia, lecturing on her subject at the University. But the Tsunami changed all that. She was recruited by Concern and immediately found herself putting her studies to practical use in the barracks.
"At first, I was a bit overwhelmed by the task but I've learnt a lot from Karanja. I had hoped to become a lecturer but now I'm really happy in my work - I'm using my skills to help my fellow citizens. Also, I've made a lot of friends in the barracks, they are like family."
Over the months Aldalina has listened to many survivors' stories and is a person they turn to for help. She stops to chat with a woman wearing red dress and white veil, sitting on a porch. Like everybody in the camp, Syaritah Nurmala, 42 years, has a terrifying and heartbreaking tale of survival.
Syarith's husband was a civil servant and the family lived a comfortable middle class life. With his regular Government salary they could afford a car, television and a computer for their teenage son. Her eyes well up as she recalls her past life.
"At the end of each month, if there was money to spare I would treat myself to new clothes or some make-up. Life was good, we were really happy."
When the first wave crashed in Syaritah managed to grab hold of a tree but saw her husband and son washed away by the wall of water. Although she survived the deluge of the two waves that followed, she was badly injured and bleeding heavily.
"A helicopter took me to hospital where I received seventy two stitches" she said, pulling up her sleeve to reveal a vivid red scar running the length of her arm.
"When I was better, I returned to my house but it was gone. There was not even a spoon left. I stayed in a mosque for a while and then I moved here. The conditions were very bad - mud and dirty water everywhere. It was difficult to keep clean and my skin was itching."
Aldalina walks on through the barracks to catch up with Karanja and the job of managing the infrastructure camp. They cast expert eyes over pipes and ditches, discussing how to further improve the water supply and drainage. Concern's engineering team work in six similar barracks, assisting over 5,000 people. With over 500,000 made homeless by the disaster, the reality is that it will take years, not months to rebuild their homes.
For the residents of Camp Raider life will never be the same and the emotional scars may never heal. But for as long as they remain in the barracks, Concern engineers will be there to ensure that their basic but essential needs are taken care of.