It's costing me about £7,000 with just a sand surface ( I will put rubber on eventually when I can afford it!)
The majority of it has gone on drainage with 180 tonne of limestone and drains put in even though it has had an arena on site for the last eight years!!!! the drainage was rubbish.
There is really no need to spend a fortune on drains. I 'reclaimed' a piece of my field which was a bog. Simply scraped off the top 6 " of earth, formed the sides of the arena with the earth, then over the space of a few months, had local skip companies dumping their building rubble into it. that was all flattened down with a huge ride on vibrating roller. This was a good 2ft deep, if not 3ft. this was followed by about 8" of scalpings, again firmly compacted down using the vibrating roller. then the surface laid on top. No drains, no membranes. Just build the 'traditional' way. The arena NEVER flooded and was a dream to ride on. It just meant that the arena was about 3ft higher than the field, as opposed to being the same level. The expense was mainly the fencing, which was done by a fencing contractor and was very substantial (and lovely to look at). Arenas drain even better if built on a very slight incline (very very slight). All that drains to is block up, and all that membranes do is rise up. I heard of a horse break its leg on a membrane. I firmly believe the old fashioned methods are best, and very cost effective.