Dry lot design tips
There are many benefits of incorporating a dry lot(s) into your environmentally-friendly equine facility. A properly designed dry lot provides an attractive alternative to stalls as an area where horses can be turned out as a herd to help manage and protect pastures. Below are key tips on proper dry lot design.
Size – A general rule of thumb is 400 to 500 square feet per horse.
Grading – Similar to an arena, a dry lot should be graded with a 1 to 4 % slope. A completely flat area will not drain water, whereas a slope greater than 4% will be difficult to maintain footing and not provide a flat enough surface for horses to stand for long periods.
Storm water runoff management – Diverting storm water away from the dry lot is critical. The best strategy is to locate the dry lot on high, dry ground; however, this is not always feasible. When grading the dry lot, it is strongly advised to also grade a grassed swale or install a french drain system along any areas uphill of the dry lot to capture and redirect surface water runoff. You will be glad you invested in this feature the first time you get a heavy rain.
Footing – Proper footing is another critical factor. Good footing design starts with a properly graded and compacted sub base. A base layer 3 to 6 inches deep of crushed rock -- either screenings or 1.25” minus crushed rock -- works well. The base should also be compacted, either by machine or by allowing the material to settle for several months.
When budgeting for a dry lot with improved footing, it is strongly recommended to not cut corners on the sub-base and base work, as they are critical to long term performance and costly to repair in the future. It is recommended to err on a smaller dry lot that you can afford to design correctly versus a larger dry lot if that means cutting corners on design.
The top footing, on the other hand, is an area where you can start economically. 1.5 to 2” of sand or screenings is a good place to start. After a short while, you will get real world feedback on the performance of your footing to guide you in amending the footing to improve desired performance. Is it too hard, too dusty, to slippery? With top footing, it’s much easier to add to than remove and replace.
Finally, when selecting footing, ask the quarry for a gradation report, which is a summary of the particle size distribution of the sand or crushed rock footing. This will provide you with important information as to the likely performance of the footing. Gradation reports can be difficult to interpret, so you may want to reach out to your local Ag Extension agent or equine facility design expert for assistance.
-Edited from article by Clay Nelson published in Equine Wellness magazine