Organizers of the Reading Festival remain upbeat about the weekend, despite being forced to close some parking lots and campsites because of flooding from the nearby river Thames. This year's headliners are Razorlight, Red Hot Chili Peppers and Smashing Pumpkins.

In an open letter to festivalgoers at Readingfestival.com, Melvin Benn, MD of Festival Republic outlines in detail the extent of the problems on the site, with some camping areas still not suitable for use after being waist-high in water last month.

"It has been a very difficult month," writes Benn. "We have recovered to a large extent but not fully." He adds that several areas are "unusable" and his posting updates ticket-holders with the latest situation in each of the campsites so they can plan where to pitch their tents.

In his message, Benn reassures people with tickets to the 80,000-capacity festival that it will "get better" by Friday, and he adds that the weather forecast for the weekend is "quite good." Benn admits this year's three-day festival at Richfield Avenue has been a "challenge" and credits the efforts of Reading Borough Council and the Environment Agency in reducing the river level.

"We will be able to stage the world's greatest rock festival despite what climate change and the weather have thrown at us," he says.

Reading is the longest-running U.K. festival, with its origins in the National Jazz & Blues Festival in Richmond in 1961. The event settled in Reading in 1971 and it is now staged as part of the annual Carling Weekend, with the alternative leg held in Leeds at Bramham Park.