Depending on the crossing, you can replace a culvert with a broad-based dip, a bottomless arch, a box structure, a short bridge, a hardened ford, or with nothing at all if the water can be routed a different way.
Which one fits depends on a question most people skip. What is actually crossing your road or driveway? Roadside runoff, an intermittent swale, and a live stream are three different problems, and only one of them usually calls for a round pipe.
Pipes are the default because they are cheap and familiar, not because they are always right. Undersized ones clog, back water up, and wash roads out. Several of the alternatives below cost less to maintain across a few decades and pass storms the pipe would not.
Start by Naming the Actual Problem
Before choosing a structure, sort the crossing into one of four categories. The right answer follows almost automatically.
| What Is Crossing | What It Usually Needs |
|---|---|
| Sheet runoff and ditch water on a low-volume road | A surface drainage feature, not a pipe |
| An intermittent swale that only runs after storms | A dip, a small pipe, or regrading |
| A defined channel with bed and banks, carrying water most of the year | An open-bottom structure or a span |
| Nothing, once the grading is corrected | No crossing at all |
Most failed pipes belong in the first or third row. A pipe in row one is more structure than the situation needs and it becomes a maintenance item forever. A pipe in row three is usually too small for a stream that behaves like a stream.
Working this out before ordering material is the whole job. Once the category is settled, culvert installation and restoration or one of the alternatives below becomes an obvious choice rather than a guess.
Alternative One, Do Not Cross the Water at All
The cheapest crossing is the one you delete.
On plenty of properties the water only needs to cross the drive because the grading sends it there. Options worth checking first:
- Regrade so water never reaches the crossing. Intercept it upslope and route it along the contour to a stable outlet.
- Convert the crossing into a conveyance. If water is traveling along your route rather than across it, an open channel or piped storm line down one side removes the crossing entirely.
- Move the crossing. Shifting a driveway thirty feet to a natural high point can eliminate the need for a structure.
- Daylight the flow. Where an old pipe is undersized and failing, sometimes the answer is opening the channel back up rather than replacing the pipe.
These are grading and drainage solutions rather than crossing structures, and they carry no long-term maintenance. Worth ruling out before spending money on a pipe.
Alternative Two, A Broad-Based Dip
This is the most underused option in Central Pennsylvania, and it is well documented here.
The Penn State Center for Dirt and Gravel Road Studies defines a broad-based dip as an intentional watercourse and associated high spot built across a roadway, carrying water from the uphill ditch over the road surface to a discharge area. The Center states directly that broad-based dips can be used in place of cross pipes in certain situations to outlet water from the uphill ditch across the road.
The advantages are straightforward. Nothing to clog. Nothing to rust or crush. No inlet to clean out after every storm. The Center notes a dip also prevents accelerated aggregate loss and sediment generation by stopping drainage from running a long distance down the road.
Design points the Center specifies:
- Angle it 20 to 40 degrees across the road, not square across like a speed bump. A dip set perpendicular is more likely to fail and causes more erosion, because it forces water to turn a right angle to cross.
- Give it continuous fall toward the outlet end, the same as a pipe.
- Reinforce the bottom on steeper grades, with hard stone or geosynthetic material.
- Stabilize the outlet. A dip discharges concentrated flow just as a pipe does. Outlet into a vegetated buffer where possible, with rock armoring where flow demands it.
- Mark it so it does not get graded out during future road maintenance.
Dips suit low-volume roads, farm lanes, and long driveways. They are less appropriate where plowing is heavy or traffic speeds are high. Building one correctly is shaping work, which puts it with excavation and grading rather than pipe installation.
Alternative Three, A Bottomless Arch or Box Structure
For a real stream, this is increasingly the recommended answer rather than a round pipe.
The Pennsylvania Department of Environmental Protection encourages bottomless structures in its stream continuity guidance, particularly on steeper channels. An open-bottom arch or a three-sided box sits on footings with the natural streambed left in place between them. The stream keeps its own bed, slope, and roughness through the crossing.
DEP’s position is that structures should be wide enough to carry the channel shape, not just the volume of water, so debris and gravel pass through instead of piling up at the inlet. A round pipe constricts a channel by design. A properly sized arch or box does not.
Pennsylvania has a clear worked example. At the Polly Pine Road crossing in Hartley Township, Union County, twin four-foot pipes carried a stream roughly 15 feet wide. The pipes clogged repeatedly and the road flooded in heavy rain. Under the stream crossing replacement standard developed by the State Conservation Commission with Penn State’s Center for Dirt and Gravel Road Studies, they were replaced with a 22-foot-wide concrete box culvert, which allowed a natural streambed to be rebuilt through the road and greatly increased capacity. Two weeks after installation the site took six to eight inches of rain from Hurricane Debby, an event that would previously have overtopped the road.
That is the case for the approach in a single project. The structures cost more up front and stop being a recurring maintenance and washout problem. Sizing and setting one is engineered work, and it sits within stream crossing and culvert work rather than being a different trade.
Alternative Four, A Bridge or Short Span
Once a crossing gets wide enough, a span becomes competitive with a very large pipe, and it removes the constriction entirely.
A bridge makes sense where the channel is wide, the banks are stable enough to found on, the fill depth for a culvert would be excessive, or the crossing must pass large debris. It also avoids the inlet clogging problem completely, because there is no inlet.
The trade-off is foundations, span design, and inspection obligations. For small private crossings, a timber or steel beam span on prepared abutments is often more achievable than people assume. Our article on the cheapest type of bridge covers where the cost lines fall between span types.
Alternative Five, A Ford or Hardened Crossing
A ford lets vehicles drive through shallow water on a reinforced surface instead of over a buried structure.
Fords work in specific conditions:
- Low traffic volume, and drivers who can wait out high water
- Shallow, stable channel with a firm bottom or one that can be armored
- Gentle approach grades on both banks
- Farm lanes, woods roads, and secondary access rather than primary access
They do not work as the only access to a home, and they are not a way to avoid permitting. Any work in a channel with defined bed and banks is regulated in Pennsylvania regardless of whether a pipe is involved.
Where a ford does fit, the maintenance profile is attractive. Nothing clogs, nothing rusts, and high flows pass over the top rather than backing up behind a structure.
Why Two Small Pipes Are Not a Substitute for One Big One
This deserves calling out because it is the most common improvised alternative and it consistently fails.
The reasoning seems sound. Two 18-inch pipes should carry what one 24-inch pipe does. In practice, twin pipes create two narrow inlets instead of one wide one, which doubles the number of places debris can jam. They rarely sit at matching inverts, so one carries most of the flow and the other silts up and stops working. They constrict the channel more than a single opening of equal area. And they collect gravel between and around the ends.
The Polly Pine crossing above is exactly this pattern. Twin four-foot pipes on a 15-foot stream, chronic clogging, and a flooded road, resolved by a single 22-foot opening.
If the existing pipe is undersized, the answer is a bigger single opening or a different structure, not a second pipe beside it.
Comparing the Options
| Option | Best For | Main Drawback |
|---|---|---|
| Regrading or relocation | Crossings that exist only because of poor grading | Not always geometrically possible |
| Broad-based dip | Low-volume roads, ditch flow, farm lanes | Not suited to high traffic or heavy plowing |
| Round pipe culvert | Roadside ditches, small intermittent swales | Clogs, constricts channels, limited capacity |
| Pipe arch or elliptical | Same as round pipe with limited cover available | Costs more, fewer suppliers |
| Bottomless arch | Live streams, steeper channels | Needs footings and engineered design |
| Box structure | Wide streams, high flows, road crossings | Highest structural cost of the culvert family |
| Bridge or span | Wide channels, deep fill, debris passage | Foundations and inspection obligations |
| Ford | Low traffic, shallow stable channel | Impassable at high flow, still needs permits |
When a Pipe Is Still the Right Answer
None of this makes culverts obsolete. A correctly sized pipe is the right structure for most driveway crossings over a roadside ditch, and it is cheap, fast, and durable when installed properly.
Choose a pipe when the crossing carries a ditch rather than a stream, the drainage area is small and well understood, there is enough cover for the pipe under the driveway, and the township specifies one.
Whichever structure you choose, Pennsylvania’s Chapter 105 rules apply the same way. An encroachment is any structure or activity that changes, expands, or diminishes the course, current, or cross section of a watercourse, floodway, or body of water. A dip, a ford, and an arch are all encroachments if the channel is regulated, exactly as a pipe would be. County conservation districts administer much of this under delegation from DEP, and districts covering Adams County and the surrounding counties will confirm which permit applies before design work starts.
Final Thoughts
The best alternative to a culvert depends on what is crossing. Ditch runoff on a low-volume road often wants a broad-based dip. A live stream generally wants an open-bottom arch, a box structure, or a span. Some crossings disappear entirely once the grading upslope is corrected. Only a portion of the situations people assume need a pipe actually do.
The pattern worth avoiding is replacing a failed structure with a slightly different version of the same failure. If a pipe has clogged and washed out twice, a third pipe is unlikely to behave differently. The Polly Pine crossing went from twin four-foot pipes to a single 22-foot opening and rode out an eight-inch rain event two weeks later.
JDI Site Solutions builds culverts, box structures, fords, dips, and bridge crossings across Adams County and Central Pennsylvania, and can tell you which one the site actually calls for. Call JDI Site Solutions to have the crossing looked at before you order a pipe.