Heavy Use Areas – How-To and Essentials
/by Michael Hipp
One of the the most common problems I see on properties I visit is that folks have tried to build a Heavy Use Area (HUA) to confine their horses off pasture for the winter, but they did not know how to construct one properly and have ended up with mud anyway. So, as we come out of winter and see that those HUAs are really in bad shape and need to be remade, let me offer this basic how-to and essentials for a proper HUA that will last for many years.
It Starts With The Right Base
A lot of well-meaning folks think that just putting down enough gravel is a HUA, but that is only part of it. Because of the many soil types we have in western Washington and the many ways they perform when wet and under pressure, just adding gravel is actually a costly mistake. The soils will slowly suck the gravel into itself - the most common soils are titled “gravelly” because gravel is a major component – and you will never see it again. This does not take long, either, and a lot of folks who put down gravel last September can’t see it in March! So, building a proper HUA starts with the right base. That base is called “Road Cloth” or “Geotextile”.
The geotextile that we recommend must conform to Material Specification MS-209. If it does not then it will not perform properly and eventually will be broken down and the HUA will fail. A lot of folks believe that just putting down “landscape cloth” of some kind like you can purchase at big-box home improvement centers is good enough, but it is not. The goal in building an HUA is to basically build a road bed that a car could drive on (or tractor, many times). This is appropriate because you will have an animal that is very similar in size and weight as most tractors on most farms. So, material selection is vital, and so is how you install it. If you need some guidance on where to obtain cloth that meets this specification you can contact us any time.
Next Important - Footing Selection
We recommend, for a basic HUA, using 5/8 minus gravel as your footing base. The reason is that we have found that 5/8 minus packs together very tightly to build a HUA that does not fall apart easily and provide a good, level footing for the horse. It is also the best at draining water through itself and off itself, creating a much drier area. Yes, there are other types of footing that can be used, and should be used depending on various factors (age, possible hoof issues, etc.) and these options can be and should be discussed with your veterinarian and farrier, but for the typical, healthy horse we recommend 5/8 minus.
The How-To
To build a proper HUA that will last many years – possibly 10 years or more – before needing to be refurbished you will need to do the following:
1. Select the best site
Site selection for your HUA is a critical first step. The best sites are on the highest and driest locations on your property away from water features like streams or wetlands. It should be located adjacent to your barn or stable, where your horse can have access to it from their stall. It should also be in a position to be easy to clean manure from and be in a fairly level place, not on steep slopes.
2. Sizing your HUA
Determining the size of your HUA is dependent on a lot of factors: the amount of land you have available, the age and activity level of your horse, and any other particular behavior issues your horse may have (is your horse nervous near the forest’s edge, or do they need to be able to see your house to not pace?). As a rule of thumb the average, 15 hand tall horse should have at least 700 square feet of space. For the typical barn, with 12 ft wide stalls, that would mean an area of approximately 12 ft wide x 60 ft long. If you will have multiple horses in one area you will need to multiply that by the number of horses. Again, sizing is dependent on many factors, so reach out to us for specific advice when you are ready.
3. Eliminate water Intrusion
The goal in this step is to eliminate as much intrusion of water onto and through your new HUA. A good HUA is designed to withstand hard rain, but it will not stand up very long with a constant flow of water across it or through it like a small stream created from a downspout. Make sure you have gutters on your shelter to prevent roof runoff from falling onto your HUA, and channel the downspouts away from the HUA, or connect them to an underground outlet that takes the water away to a safe place.
4. Grade the area
This is another vital step that will help preserve your HUA and make it function as intended. You will want to dig down 6 inches and then grade that area. Or, if you chose, you can grade the surface and use a retention frame of some kind, because the footing material will need to be at least 6 inches deep. When you grade the HUA make sure it has at least a 1 – 2% slope away from your barn or shelter. That means the soil must drop about 1.25 – 2.50 inches every 10 feet. This will ensure the rain will come through the gravel, hit the geotextile fabric, and shed off properly, keeping the HUA dry. Make sure the grading will send the water to a place it can safely go and be absorbed by the soil.
5. Install the geotextile fabric
You will want to lay the fabric down with the slope keeping in mind how the water will flow, like the shingles on your house roof. The fabric may have to overlap, in which case it should overlap at least 2 ft to allow for any shifting. Make sure the end at the bottom of the slope extends beyond the HUA so you can cover that end with earth. Use garden staples to secure the fabric to the ground.
6. Use a retention perimeter
Install a retention perimeter of some kind – pressure treated lumber, for example – or extend the cloth out so it can be wrapped upward to retain the footing. This can be vital in most situations to prevent the gravel footing from migrating horizontally into the soil and thus losing your it. Be sure to leave 1 – 2 inch gaps in places that will allow for water to escape and migrate.
7. Spread the footing
Spread the footing at least 6 inches deep, compacting it with a hand compactor (available at most equipment rental places), compacting at 4 inches and then again when you reach the final 6 inches. Use a water hose to wet the area and compact it until the surface is firm.
Filter Strip next to paddocks, fenced off from the pasture.
8. Maintain a filter strip around your HUA
Since the water from your HUA needs to go somewhere and be absorbed so it won’t create a muddy condition, I recommend keeping an area where the water sheds off the HUA that you can allow grass to grow and where your horses can’t disturb it, called a “filter strip”. Keep in mind that your HUA will be capturing a lot of water that has been contaminated by horse manure (a 700 sq ft HUA could potentially capture 14,000 gallons or more in a season!), and the best way to treat that water is by allowing a good grass filter strip to absorb it.
Contact Us for Specific Advice Any Time!
By following this basic guidance you will be able to construct a proper HUA that will last for many years. If you would like specific guidance for your property and conditions, contact us any time! We are always here to help.
