Nick Young: In Haiti, rain deluges people's tents, and their needs are still vast

Heavy rains have turned the spotlight back on Haiti. It's pouring again as I arrive, the water sluicing down on tents and makeshift shelters. Along with the shock at the continuing human suffering following January's earthquake, the images are provoking another reaction; why, when so much money has been donated, are people still living in appalling conditions? Why, when the world knew the rains were coming, are people still forced to shelter under tarpaulin? Where are the new houses? Has the relief effort dissolved in the rain?

Haiti represents one of the fastest aid distribution operations ever undertaken. This week, shelter distributions led by the Red Cross will reach their millionth person. Tarpaulins, tents and plastic sheeting have been put into the hands and over the heads of around 100,000 people a week. This is despite well-publicised problems including a devastated port, blocked roads and a clogged airport.

I visited La Piste and AutoMeca camps, both amazingly clean and tidy, despite the grotesquely overcrowded conditions. We've built new latrines here, despite the shortage of space and wood – one for every 209 people. The target is one for every 100. The kids all call out; earlier, they were dancing with two clowns who were teaching them basic hygiene messages. But hygiene is a distant concept with so few toilets, so little clean water, for so many people.

The needs are vast and we always want to go faster but we have to be realistic. In New York, in the richest country in the world, teams of the best equipped experts on earth took two years to clear the rubble of the World Trade Centre. We must not let pressure to speed up our response lead to errors of judgement which could undermine recovery, and jeopardise people's lives.

Rubble is being cleared, and new sites are being identified so that those in most danger can be evacuated to safer places. Agencies have begun work on robust transitional shelters, but it is inevitable that thousands will be living in temporary shelters in camps when the worst rain hits.

Agencies are working relentlessly, but it is a sad reality that, with the rains coming, the situation for people living in the camps will get worse before it gets better.

Sir Nick Young is CEO of the British Red Cross;