Shoreline erosion on the Iowa Great Lakes is not one problem. It’s usually three at once. Waves undercut the toe all summer. Ice push, which happens in the warm spells after the lake has frozen, can keep working a bank into March. Then high water, like the 2024 flood, takes chunks out of a bank that’s already weakened. For shoreline erosion control on these lakes, the State of Iowa sets the rules, and they are tight. Erosion protection is limited to native stone riprap reaching no more than 4 feet past the ordinary high water mark. You can’t add fill to win back ground you’ve lost, and walls have to sit above that line. All of it needs a DNR sovereign lands permit before anybody starts.
Riprap runs about $70 to $400 per linear foot nationally, per Angi’s 2026 data. Fall is the time to look at your bank and get the paperwork moving, before the ice does what it does.
Key Takeaways
- Waves, winter ice, and flood events do most of the damage. Runoff from the yard finishes it.
- On the Iowa Great Lakes, the fix is native stone riprap within 4 feet past the high water line, with a DNR permit.
- You can’t fill back land you lost to erosion. The goal is to stop the loss, not reverse it.
- The strongest setup pairs rock at the toe with deep-rooted native plants above it.
- Riprap runs about $70 to $400 per linear foot nationally (Angi, 2026), and access drives the number.
What causes shoreline erosion on our lakes?
Usually more than one thing at once. That’s why a single fix often fails. You put rock at the toe and the bank still slides six months later, because the water coming off the yard was the thing doing the damage the whole time.
Waves and wakes
Every wave that hits a bare bank pulls a little soil out from the bottom. Do that all summer on a busy stretch of West Okoboji or Big Spirit and the bank gets undercut. The top looks fine right up until it drops into the lake. A good thunderstorm week can take soil off a bank, and by the time you notice it, the damage is already done.
Ice push
This is the one people from out of state don’t believe until they see it. The Minnesota DNR, whose lakes freeze the same way ours do, explains it well. The ice sheet cracks in the cold. Water fills the cracks and freezes, and the sheet grows. When the weather warms, it expands again and shoves toward shore with enough force to push soil and rock into ridges. It can wreck retaining walls, docks, and lifts. A wall that looks solid in October can be leaning by April, and nobody’s around to see it happen.
High water
The summer 2024 flood was a hard lesson. According to the Iowa DNR, more than 90 shoreline segments around the Iowa Great Lakes collapsed in that flooding. Saturated banks get heavy and weak at the same time, and a steep one can let go in a single afternoon. One afternoon. The neighbors’ bank held, and yours didn’t.
Trouble from the top
Not all erosion starts at the water. A downspout dumping straight down a bluff cuts a gully every time it rains. Turf mowed right to the edge has roots a few inches deep, which hold almost nothing. Big trees leaning over the water are their own risk. On a DNR restoration project on East Okoboji, a state fisheries biologist pointed out that cottonwoods have shallow roots, and one tipping over can tear out a large chunk of shoreline. So the fix isn’t always at the water. Sometimes it’s a pipe reroute up at the downspout.
How do you know your shoreline is failing?
Walk your frontage after the dock comes out, when you can actually see the bank. Don’t wait until spring to notice. By then you’ve lost a season. Look for:
- A lip of sod hanging out over open air, with the bank carved away underneath.
- Tree roots exposed on the face of the bank.
- Cracks running parallel to the shore a few feet back from the edge. That’s the next piece getting ready to go.
- Old rock slumped down into the water, leaving bare dirt behind it.
- A wall that is leaning, bulging, or has gaps opening at the joints.
- Muddy water along your frontage after every rain while the neighbors’ water stays clear.
Any one of those means the bank is moving. Two or more means it’s going to keep moving until somebody does something about it.
What are you allowed to do on your shoreline?
Less than most people assume. And this is the part to get right before anyone shows up with a skid steer, because fixing it after the fact is a lot harder than getting it right first.
Spirit, East and West Okoboji, Center, and Silver in Dickinson County are on the state’s list of meandered sovereign lakes, along with Lost Island and Five Island in Palo Alto County and Storm Lake. The State of Iowa holds title to those lakes in trust for the public. The lakebed and the water belong to everybody, and the Iowa DNR requires a sovereign lands construction permit for any construction on, above, or under them.
The rules themselves are in Iowa Administrative Code chapter 571-13. In plain English, on a sovereign lake:
- Rock is the tool. Erosion protection is limited to native stone riprap: broken limestone, dolomite, quartzite, or fieldstone that meets a DOT spec. It can extend no more than 4 feet horizontally out past the ordinary high water mark.
- No dirt in the lake. Earth fill is not allowed below the high water mark.
- You can’t win back lost ground. The DNR will not permit fill beyond the high water mark to regain land lost to erosion. If the bank moved 6 feet back, that 6 feet belongs to the lake now. I know that’s not what people want to hear.
- Walls go above the line. Retaining walls, sheet piling, and gabions have to sit above the high water mark. A wall placed right at the mark has to be faced with riprap.
The “ordinary high water mark” is where water has sat long enough to kill off land plants or saturate the root zone. It’s usually not where the water is in October, so it’s worth having it marked before anyone plans a project. You’d be surprised how often a project gets designed to the wrong line.
You apply through the DNR’s PERMT site. Per the DNR, there’s typically no fee, applications are reviewed first in, first out, and your contractor can be the point of contact if you designate them. One catch: PERMT does not send your application to the U.S. Army Corps of Engineers. Any federal permit is a separate step. Your dock permit is separate too, and it does not cover rock or walls.
Rules change, and every lot is a little different. Check your specific project with the DNR before work starts. We won’t tell you to skip a permit, and neither should anybody else.
Riprap, retaining wall, or native plants?
The best answer is usually some of each, in the right places. The DNR’s own Pilsbury Point project on West Okoboji is a good model. Crews are regrading steep slopes, armoring the toe with rock, and seeding deep-rooted native vegetation above it. Not one thing, all three, in sequence.
Riprap at the toe
The toe is where the water and ice hit, so that’s where the rock goes. Riprap absorbs wave energy instead of bouncing it back, and when ice pushes it, it shifts and settles instead of cracking. It also happens to be what the rules allow. Done right, it sits on a graded slope with fabric underneath so the soil can’t wash out through the gaps. Skip the fabric and the soil underneath the rock washes out, and the rock’s gone too.
Retaining walls up top
A wall makes sense for holding a terrace or a patio back from the bank. It has to stay above the high water mark anyway. The weakness of a straight wall at the water is that waves reflect off it and scour the bottom in front of it, and ice push hits it head-on. That’s why the old walls built right at the water’s edge are the first ones around the lakes to start leaning.
Native plants above the rock
Deep-rooted native grasses and shrubs knit the upper bank together in a way turf never will. They also slow down runoff from the yard and give you a buffer you don’t have to mow. Plants alone won’t hold a bank that’s taking waves at the toe. But above good rock, they’re what keep the slope from sliding. The combination is what makes it last.
Fix the water coming from the house
If a downspout empties onto the slope, all the rock in the world won’t stop the gully it cuts. Rerouting it into a pipe or a drain to the bottom of the bank is cheap and often the first thing to do. Sometimes the only thing to do. Our gutter crew handles downspout reroutes.
What does shoreline erosion control cost?
Angi’s 2026 data puts riprap at roughly $70 to $400 per linear foot, with an average project around $20,000 and most running $10,000 to $30,000. The rock itself runs about $20 to $110 per ton. That range is wide, and it’s wide because shoreline projects are all over the map. Here’s what moves the number on a lake lot around here:
- Length. Riprap is priced by the foot of frontage, so 60 feet and 200 feet are very different jobs.
- Slope. A steep bluff that needs regrading before rock goes on costs a lot more than a low bank.
- Access. This is the big one on the lakes. Many lake lots have no way to get a truck to the water without tearing up the yard, so the rock comes in by barge. That changes the number fast.
- What’s above the rock. Plantings, a wall, steps, or drainage all add to the job, and they’re often what makes it last.
- Old work. Pulling out a failed wall or slumped rock comes before anything new goes in.
One national number won’t apply here. Angi lists permits at $525 to $3,050, but Iowa’s DNR says its sovereign lands permit typically carries no fee. A firm price takes someone walking your frontage, and that visit is free.
Why plan it in the fall?
Because October is when you can actually see the problem. The docks and lifts are out, and summer’s damage is right there in front of you. The winter warm spells that drive ice push start once the lake has frozen, and a bank that’s already undercut has a tough winter ahead of it. You don’t have to wait until the ice does the work for you.
It’s also about getting in line. The DNR reviews permit applications first in, first out, so a complete application filed this fall is ahead of everyone who waits for spring. And honestly, our barges are busy right now pulling docks before the December 15 deadline we covered in our fall dock and hoist removal guide. Spring fills up fast once the docks start going back in. The people who planned in the fall are the ones who get their shoreline done before Memorial Day.
How Midwest handles shoreline work
Shoreline work is where being one company with several crews actually matters. Midwest Landscape & Design does the shoreline restoration, erosion control, rock work, and plantings. Midwest Lake Service runs push barges that haul heavy equipment and rock in by water, so we don’t have to drive a loader across your lawn. If the plan calls for a retaining wall or a patio up top, our Midwest Concrete & Excavating crew builds it. Same company, same phone number, and nobody pointing fingers at the other contractor when something settles. I like that part.
We work the Iowa Great Lakes and the lakes around them, including Storm Lake. The first step is a walk of your frontage with someone who has done this on these lakes, so you know what’s happening to your bank and what the rules allow before you spend anything. That walk is free, and it’s the best way to figure out if you need a 60-foot riprap job or a 200-foot one.
FAQ
Do I need a permit to put rock on my lake shoreline?
On a meandered sovereign lake, including Spirit, East and West Okoboji, Silver, Center, Lost Island, Five Island, and Storm Lake, yes. Any construction on state-owned lake land or water requires a DNR sovereign lands construction permit before work starts. You apply online through the DNR’s PERMT site.
Can I fill in the part of my yard that washed away?
No. Iowa’s rules specifically prohibit fill beyond the ordinary high water mark to regain land lost to erosion. The realistic goal is to stop more loss and stabilize what you have left. I know that’s frustrating. It’s the rule.
Can I build a seawall on my lakefront?
A retaining wall has to sit above the ordinary high water mark, and one placed right at the mark has to be faced with native stone riprap. Below the high water mark, riprap is the only erosion protection the rules allow on sovereign lakes. There’s no workaround there.
Does my dock permit cover shoreline work?
No. Docks, hoists, and buoys are permitted separately. Rock, walls, and grading at the shoreline need their own sovereign lands construction permit. Two different applications, two different reviews.
How much does riprap cost on a lake?
Nationally, about $70 to $400 per linear foot, per Angi’s 2026 data, with most projects between $10,000 and $30,000. Slope and access drive where yours lands. Barge delivery is common on lake lots where trucks can’t reach the water, and that adds to the number. Get a local walk, not a phone estimate.
If your bank lost ground this year, schedule a call. We’ll walk your frontage, tell you straight what’s going on, and help you get a plan together in time to file before spring.