Riding Arena Construction Guide: Part 3 – Laying the Base
In this guide we will be explaining how to lay your riding arena base. It is very important that any fast-moving water is directed away from the arena or collected and diverted. This is normally achieved with a toe or cut drain at the bottom of the cut bank, which will collect water coming down the bank and steer it away from the arena. If there is a large amount of land, car parking or other hard standing surface situated above the arena, we recommend diverting the water with an earth bund and/or drain at the top of the bank
Measure out the arena size, ensuring that corners are at 90° right angles. The easiest way to do this is to measure from corner to corner, across both sides. The measurements should tally, at which point you should insert some corner pegs.
Mark a line halfway between the bottom of the bank and the edge of the new arena. The next step is to dig a 300mm x 450mm (w x d) trench along the bottom of the cut bank, emptying out the collected water into a field, or convenient ditch.
Now it’s time to lay your pipe in this trench. You can line the trench with membrane or, alternatively, wrap the pipe in membrane to avoid the pipe becoming clogged with washed in mud. Make sure the trench has a slight fall in the chosen direction to allow water to drain away. In most ground conditions, especially on clay and soil, we recommend that you dig drains through the arena every 10m.
For example, a 20m wide arena would have one drain down the centre to help drain excess water. This drain can be linked into the cut off drain.
2. Laying the Lower Membrane & Drainage Stone
We recommend that you lay your lower membrane and drainage stone at this stage, as this will ensure you have a hard base to work on during wet conditions.
Run a string line down one long side of the arena and unroll the first strip of your membrane, making sure that approximately 150mm of the membrane projects past the fence line. When you roll out your next run of membrane, make sure that you have a minimum overlap of 300mm.
Lay your stone roughly as you go, keeping it back from the edges of the arena by 1m, leaving yourself room to install the fencing. We recommend placing all the stones on the area at this stage but leave grading until later. Some of the stone can be used to fill up the drainage channels.