But the Olympic equestrian team is confident rain will not stop play in Greenwich.
“Greenwich has very freely draining turf, more so than many other horse trials sites,” said Tim Hadaway, the equestrian competition manager for the 2012 Games.
“Our work for the past two years has been in trying to keep moisture in the ground.”
Mr Hadaway told H&H that when Badminton Horse Trials was cancelled in April, he went around the London course with turf specialist, the Sports Turf Research Institute.
It told him that, despite all the rain, it would only take seven days of dry weather before they would have to irrigate again.
“That rain – we had 60 or 70mm in a couple of days – allowed them to identify any areas of standing water, which needed further work. These guys know every inch of the course,” he said.
However, if the rain continues to fall, wellingtons may be sensible wear on cross-country day, because 50,000 people on the course might cause a few pinch points to become muddy.
But Mr Hadaway said these can be fenced off if necessary.
“I feel we have done everything possible to design risk out of the site and mitigate all possible issues,” he said.
General venue manager Jeremy Edwards said a spare day – 1 August – has been worked into the equestrian timetable, to be used if the rain causes delays to eventing.
FEI rules state “competitions must not take place in extreme weather conditions, if the welfare or safety of the horse may be compromised“.
The ground jury can halt a competition in such conditions.
But spectator tickets will remain valid for the event – even if it is rescheduled.
This news story was first published in the current issue of H&H (12 July 2012)