For any highway department, managing water flow in roadside ditches is a key part of keeping roads in good shape and protecting nearby land. One simple but powerful tool for the job? The check dam.

Check dams are small structures, temporary or permanent, built across a ditch to slow water down, reduce erosion, and trap sediment. They’re a great way to help keep ditches from washing out or dumping silt where it doesn’t belong.

Depending on what you’re dealing with, there are a few different types of check dams to choose from. Here’s a quick rundown:

Rock Check Dams

What they are: Built from riprap or other sturdy stone.

Good for:
✔️ High-flow ditches
✔️ Steep slopes
✔️ Places where you need long-lasting durability

Pros:
✅ Built to last
✅ Handles fast-moving water well
✅ Can take multiple big storm events

Things to keep in mind:
⚠️ Higher up-front cost
⚠️ Must be sized and placed correctly to avoid upstream flooding

🌲 Log or Timber Check Dams

What they are: Made from logs, timber planks, or treated lumber.

Good for:
✔️ Rural or forested areas
✔️ Low-to-moderate flow ditches
✔️ Temporary construction projects

Pros:
✅ Materials often easy to find locally
✅ Affordable for short-term use

Things to keep in mind:
⚠️ Not ideal for high-flow or permanent use unless engineered carefully
⚠️ Wood can rot over time

🌾 Straw Bale Check Dams

What they are: Straw bales staked across the ditch.

Good for:
✔️ Small construction sites
✔️ Low-flow ditches
✔️ Short-term use

Pros:
✅ Cheap and simple to install
✅ Great for sediment control on short projects

Things to keep in mind:
⚠️ Breaks down fast—needs replacing often
⚠️ Won’t hold up in high-flow or long-term situations

🧵 Silt Fence Check Dams

What they are: Silt fence fabric stretched across the ditch.

Good for:
✔️ Very low-flow ditches
✔️ Construction sites
✔️ Controlling sediment during development

Pros:
✅ Quick and easy to put in
✅ Works well for trapping sediment

Things to keep in mind:
⚠️ Can’t handle large volumes of water
⚠️ Can fail if flow gets too high

🌀 Fiber Roll (Wattle) Check Dams

What they are: Tubes filled with straw, coir, or synthetic material and staked in place.

Good for:
✔️ Low to moderate flow ditches
✔️ Stabilizing new slopes or ditch lines
✔️ Ditches where you’re planning to establish vegetation

Pros:
✅ Flexible and easy to install
✅ Biodegradable options available
✅ Helps promote plant growth for long-term stability

Things to keep in mind:
⚠️ Not suited for steep or high-flow channels
⚠️ Needs regular inspection and upkeep

Picking the Right One

Choosing the best check dam depends on a few things:

• How much water you’re dealing with (high flow vs. low flow)
• The slope of the ditch
• How long you need it (temporary vs. permanent)
• Your budget
• Any environmental concerns

Sometimes, using more than one type makes sense. For example, fiber rolls or silt fences can work great during construction, while you install rock check dams for long-term control.

Bottom line: slowing water down is key to keeping your ditches (and roads) in good shape. Check dams are a simple tool that can make a big difference.