Fencing Over Water Gaps Q&A

Whether you’re managing ranchland in the watershed of the mountains or taking care of pasture ground in the flatlands, spring thaw means more water on your property. If your fence line crosses a river, stream, or creek, ensuring your water gaps are secure is a critical spring activity. Bekaert Fence Pro, Steven Sarson shares his expert recommendations after working with acreage, farm and ranch owners for more than 30 years. 

Q) I have a stream that runs into and across our property.  Do I need to worry about a water gap? 

The ideal water gap keeps animals in and acts as a floodgate, allowing water and debris to continue flowing. 

If you have cattle or horses, you can allow up to two feet above the waterline. If you have smaller animals like goats and sheep, you will want a more secure space between the water and the fence’s bottom.  Consider a submerged fence that allows normal water flow and swings out of the way when the current increases.

Q) We need to address a creek on our acreage. How do I decide what kind of fencing to use to keep our animals in yet continue to allow water to flow?

There are no “one-size fits all” when it comes to water gaps. The best advice is to think about your stream and its banks as a U-shape you are trying to fill. 

The structure itself has three major components: 

1. Posts on each bank. If you anticipate soft banks or potential soil erosion, move the posts 2-3 feet away from the water’s edge. You can also use the next post in line on each side. 
2. Wire/cable running across the top of the water on each side of the bank. Fasten this cross-wire at the bottom of the post, which is also the top of the bank.
3. Gate materials. There are a variety of components you can use for the section of your fence that crosses the water. Use woven wire, livestock panels, treated wood boards, low-carbon barbed wire, or electric wire strands to fill the shape of the U down to the top of the water. 

Q) The water in our stream is sometimes very high and sometimes shallow. How do we account for that in our water gap fence? 

The most important thing is to ensure the gate matches the contour of the land/stream bank. If using panels or boards, cut your pieces to match the contour. In high water, the gate will swing to float in the water and allow debris to pass. In low water, livestock cannot cross under it.  

For this water gap, you can use multiple strands of barbed wire running from bank to bank.  It is commonly used in situations where there is little or no normal water flow.  

Run multiple strands across the gap and attach a rock or weight to the bottom of a center wire.  Wrap the weight around each cross wire and fasten at the top.  A wood post or log can also be used to hold down the bottom line.  This keeps your gate from gapping in low or no water situations.  

Q) Are wooden posts, metal pipes, or t-posts best for installing a water gap fence? Do I need to make a corner-style brace? 

Q) I am using an electric fence in my cattle pasture. Can I use it to cross a water gap? 

Yes. We recommend using a current-limiter on your water gap section to maintain a charge to the rest of the fence if your water gap fencing grounds-out. Remember, in most cases, an electric fence is psychological for cattle, not a physical exclusion.   A current limiter is recommended to keep the fence from shorting out when the water rises.

To prepare for installation, slide crimp sleeves on the cross wire, bend the wire 90-degrees, and crimp it down. With all pieces added, attach the cross wire to the post, and set up your limiter. 

Identifying your water gap needs based on livestock species and water flow volumes gives you a great start to your project. The installation process will go more smoothly by preparing your plan and selecting the right materials for your water gap needs.