Water Gaps
Fence that survives the creek.
A water gap is the part of a fence line that has to survive water it cannot stop. Built right, it flexes with a rise and comes back to tension when the water drops. Built wrong, it is a section you rebuild every time it rains hard, and a hole in the fence for the cattle to find. We build and repair water gaps on creeks, branches, and river crossings throughout our service area, and we build them around how that particular drainage actually behaves at high water.
How a water gap works
The fence spans the crossing without being anchored in the streambed. Heavy posts or pipe are set above the normal high-water mark on both banks, and the fence between them is hung and tensioned so rising water pushes it flat, then it recovers when the water falls. Anchoring a standard fence line into a creek bottom is what causes the tear-out.
Bank posts and anchorage
The gap is only as strong as the posts on either bank. Those posts carry the tension of the whole crossing and have to be set deep and braced, often in saturated ground. We set bank posts in concrete where the soil will not hold, and we brace them against the load from both the gap and the adjoining line.
Choosing the gap material and width
Width is set by the high-water channel, not the dry channel. A gap sized to the summer creek will be too small in a spring rise. Material choice depends on the crossing: wire that can lay flat, or a heavier assembly where debris and flow are significant. On crossings with heavy debris we set up so a limb going through does not take the whole line with it.
Repair after a flood
After a rise, the gap is where damage shows first. We reset posts, restring and re-tension, and look upstream and downstream for what will fail next. If a crossing has torn out repeatedly, the fix is usually a wider gap or heavier bank posts rather than another patch.
Water Gaps from our own jobs.
Every photo below is from work we built. Open any image to see it full size.
Water Gaps we have built.
Common questions about water gaps.
Why does my water gap keep washing out?
Usually because the gap is too narrow for the high-water channel or the bank posts are not set deep enough. Debris catching on the fence compounds it. Widening the gap and resetting heavier bank posts is the lasting fix.
What kind of fence goes in a water gap?
Wire that can lay down and recover with the water is the standard, suspended between heavy bank posts set above the high-water mark. Heavier assemblies are used where flow and debris are significant.
Do you repair water gaps after flooding?
Yes. We rebuild and re-tension gaps after rises and look at what will fail next on the crossing rather than only patching the torn section.
How wide should a water gap be?
Measure the high-water channel, not the dry creek. A gap sized to the dry channel will tear out in the first real rise.
Let's talk about your project.
Tell us what you're building, where it is, and what you need. We'll come look at it and give you a straight answer.