Courtesy of PennState Extension
Watering the footing material reduces dust levels and can put some stability back into loose, sandy, or wood-based footing. Frequent, deep watering will be part of normal arena maintenance, so planning ahead to make it a less arduous task will have long-term benefits. The objective is to keep the material moist all the way through and to have uniform water application over the surface. When an arena is not kept uniformly moist, the loose, dry areas are less stable than the well-watered spots so that horses lose confidence in what kind of conditions will be underfoot as they travel between slippery and suitable conditions.
Water the arena to keep the footing evenly moist to a 3-inch depth. Once the arena is at the moisture level that is suitable for your purpose, use a garden supply store soil-moisture meter to determine that moisture content and strive to achieve that moisture on subsequent waterings. Water an arena as you would a garden. It does not need to be flooded nor does just wetting the top fraction of an inch do any good. Give it a good watering with plenty of water in frequent, short periods. This will allow water absorption into the footing material(s) between waterings. In fact, wait about four hours or overnight before using the arena again to allow moisture to soak in. Once the correct moisture is achieved, subsequent waterings will only be needed to remoisten the top-most surface that will be drying faster than the footing underneath. Watering schedule will naturally depend on season (air temperature), wind, and sun exposure of outdoor arenas, and the indoor arena air temperature and moisture level. Watering when the arena surface begins to show signs of dustiness will preserve moisture in the underlying layer. Check the moisture level weekly and more often when drying conditions prevail, such as during times of combined low humidity, high temperature, or greater wind speed over the arena surface. On outdoor arenas, direct sunlight dries the top footing layer on a daily basis.
Watering systems include those requiring continuous or frequent human involvement for proper application of the water and those systems that are automated and once installed or setup require little human attention during the watering event. Watering that requires a high level of human involvement includes hand- held spray nozzles, garden sprinklers, and tractor-mounted sprayers. More automated systems include ceiling- or post-mounted spray nozzles and self-traveling irrigation.
Hand-held hose watering takes considerable time and is variable in uniformity of moisture addition. The benefit is that the person watering can treat wet or dry patches of arena surface with more or less water. Garden sprinklers can be set out for timed operation and moved to cover the entire arena surface over time. This allows other activities to be performed by the operator during watering but is likely to be less uniform in coverage than the hand-held technique. Puddles are common when a sprinkler stays in one area too long. Tractor- or pickup- mounted watering can be done in concert with surface conditioning. A frost-proof hydrant should be located near the arena to supply hose or sprinkler-applied water. A hydrant is a convenient tap for filling a water tank that is pulled by truck or tractor through the arena.
Automated arena watering is provided by a permanently installed sprinkler system located along the perimeter of an outdoor arena, throughout the roof framing of indoor arenas, or by mechanized field-watering equipment in both indoor and outdoor arenas. Width of arena and available water source are important factors in determining which type of system will be most effective.
Horticultural or agricultural- grade sprinkler systems (gear-driven rotors or impact heads) are suitable for providing fairly even watering of the arena surface. Ceiling-mounted sprayers (indoor arena) produce a mist of water and good, uniform coverage with proper design. Frost-proof installations are needed under freezing conditions. Landscape sprinklers can be installed around an outdoor arena perimeter to reach the entire surface with water. Indoor or outdoor sprinklers are spaced based on anticipated coverage pattern of the particular spray nozzle. Side-mounted sprinklers require substantial flow rates to spray water distances greater than 50 feet. Greater spray distances provide uneven water application with strips of dry surface between adjacent wetted circles or half-circles. For indoor arenas, the side-mounted sprinklers’ uneven water distribution results in too much water applied in some areas, which is a problem since the indoor arena base is not constructed to shed water. The sprinklers may be activated as needed or controlled by a timer.
Arena surface materials may be wetted by mechanized field-watering equipment. A flexible hose traveling system is an effective option for sites with larger arenas or with low-volume water sources. One disadvantage is that the traveling hose has to be set up each time it is used. Once set up, it operates unattended with an automatic shut-off once the sprinkler cart on the traveling hose arrives back at the hose reel. Advantages include more even water distribution than with perimeter-mounted sprinklers and potential to double its usefulness by watering both indoor and outdoor arenas. Installation and maintenance costs of automatic systems are the highest of the footing watering options, but labor is significantly reduced.
Winter watering is a challenge in freezing climates. Too much water and the footing is frozen hard; too little water and dust prevails. This is a particular challenge for indoor arenas where rider expectations are that the surface will be usable year-round. Managers may opt to reduce water additions to the indoor arena as freezing weather approaches. The advantage of having a footing material that does not compact is even more important when freezing is possible. Excess water can pass through a well-drained material, such as sand, and not bind particles together into a solid mass. Many indoor arena managers use salt to lower the footing’s freezing point during the winter and discontinue its use during warmer weather.