Before we moved to our farm, I always knew that we’d collect rainwater for our livestock. When visiting my grandparent’s farm and my uncle’s ranch as a child, I recalled they had downspouts that flowed into water troughs. So, when we moved to our homestead in 2002, we immediately put water troughs under two of the downspouts on the barn.
I had no idea at the time, but this was the reason we didn’t see a copper deficiency problem in our goats until our second year. Our well water is high in sulfur and iron, which bind with copper and causes copper deficiency in goats.
When we only had a few goats, they drank rainwater almost exclusively. But as our herd grew, they drank more, and we had to use more water from the well. Because our bucks were in a remote pen, away from the does, they had well water exclusively, which explains why none of them ever lived past the age of three for the first five years we had goats.
After learning that our goats had a problem with copper deficiency because of our well water, we added rain barrels under a third downspout on the barn. It started with one rain barrel that was purchased from the local community college when their horticulture club was doing a fundraiser. We quickly discovered that the barrel would fill with a short summer shower. To increase our storage capacity, my husband cut a hole in the side of the original barrel near the top and added a PVC pipe that goes to another small water tank.
We even had a third tank overflow connected to the second one, but it cracked when the water froze, and we haven’t replaced it yet. If you live in colder climates, you can’t use rain barrels during winter.
The challenging part, however, is figuring out when you have to drain the tanks. Of course, we don’t want to do that. We want to give our goats rainwater as much as possible because it’s healthier for them. We watch the forecast closely, and we don’t drain the tanks until it looks like temperatures will fall so low that it will be able to freeze the water in the tanks.
If you have goats, I wouldn’t really recommend big water troughs like the one in the top photo. That’s perfect for cows and horses, but goats are picky. If someone poops in the water or it looks dirty to them, they won’t drink it. Do I have to tell you what a huge pain it is to clean out a big water trough? And it’s heartbreaking to toss a bunch of rainwater.
On top of that, horse troughs are too tall for Nigerian dwarf kids to drink from. Twice we had kids wind up in one of those big troughs. One wound up with hypothermia because it was fall and already getting quite cold. Sadly, the other one was found dead because he was too small to get out before drowning.
If you have mostly sheep and goats, I’d suggest getting the water collection barrels and using them to fill up buckets. And when putting together several barrels with pipes, you can save a lot more water than you can with a big water trough.
Table of Contents
Is a rainwater collection system right for your farm?
Before installing a rainwater collection system on your barn or other outbuildings, there are a few important things to consider:
- Local regulations: Check with your local government to see if any regulations or permits are required for installing a rainwater collection system. Some areas may have restrictions on the collection and use of rainwater. And believe it or not, it is illegal in some areas.
- Roof material: The material of your barn roof can affect the quality of the collected rainwater. Metal roofs are a good choice, while roofs made of asbestos or cedar should be avoided.
- Water quality: Rainwater is generally safe for livestock use, but it may contain contaminants such as bird droppings, pollen, and other debris.
- Maintenance: Regular maintenance is required to maintain your rainwater collection system properly. This includes cleaning the gutters and downspouts and checking for leaks.
- Cost: The cost of a rainwater collection system can vary depending on the size and complexity of the system. If gutters are already in place, your only cost may be troughs or storage barrels.
How much water can you collect from a roof?
To calculate the amount of water you can collect from a roof, you will need to consider the following factors:
- Roof size: Measure the length and width of your roof to determine the square footage.
- Average rainfall: Check the average rainfall in your area. You can find this information from your local weather station or online. If you only have rain for part of the year (and snow part of the year), you can do the calculations for each month individually.
- Collection efficiency: The efficiency of your collection system will depend on a number of factors, including the material of your roof, the slope of your roof, and the type of collection system you use. A typical collection efficiency for a well-designed system is around 85%.
Once you have this information, you can use the following formula to calculate the amount of water you can collect from your roof:
Water collected = roof size x average rainfall x collection efficiency
For example, if your roof is 1,000 square feet, the average rainfall in your area is 30 inches per year, and your collection efficiency is 85%, you can calculate the amount of water you can collect as follows:
Water collected = 1,000 sq ft x 30 inches x 0.85 = 25,500 gallons per year
This calculation is an estimate and can vary based on the factors mentioned above. To choose an appropriate storage tank size, you can divide the annual amount of water by 12 months, assuming you need that much water.
If you don’t get rainfall 12 months a year, you can do the calculations for the month with the heaviest rainfall to determine what size storage tank(s) you need.
Of course, you can have multiple tanks. If you want to collect as much water as possible, I’d suggest putting a tank on each corner of the barn.
Tips for creating your rainwater collection system
To get started with rainwater collection from the roof of your barns, you will need to take the following steps.
Calculate the amount of water you need
Determine how much water you need for your intended use, such as watering crops or livestock. This will help you determine the storage tank size you will need. We lose a lot of rainwater because we bought 55-gallon barrels, having no clue how quickly they’d fill up and be overflowing. Unfortunately, it’s not unusual for us to use all the water before the next rainfall.
Install the collection system
Install gutters and downspouts on your barn roof, if needed.
Install a storage tank
Choose a storage tank that is large enough to hold the amount of water you need. Install the tank on a level surface and make sure it is securely anchored. If it’s not anchored, livestock can easily push it over and break spigots when the barrel or storage tank is empty. (Been there! Done that!)
Maintain the system
Regularly inspect and maintain your rainwater collection system to ensure it is functioning properly. Clean the gutters every fall so that the water flows through the gutters rather than overflowing.
Drain the tanks when temperatures are expected to fall a few degrees below freezing.
For more information
- Livestock and hot weather
- Avoiding Copper Toxicity in Goats
- Copper Deficiency and Toxicity in Goats
- Mineral Deficiencies and Infertility in Goats
- My Goat Story
Originally published on August 24, 2017.