Channel Migration Easements
(CMEs)

A win-win conservation program that benefits landowners, conservationists, the public, and the natural world.

CMEs pay riverbank landowners to let a river migrate naturally across the floodplain, so that the important processes of erosion and sediment deposition can continue. They protect the financial interests of landowners, while preserving the river’s natural functions and protecting vital aquatic habitat.

The Channel Migration Easement (CME) program is a new type of conservation easement in which landowners within the river’s 100-year channel migration zone agree not to armor the river banks to stop natural erosion and sediment deposition.

In return, the landowner is financially compensated for potential losses from future channel migration or flooding — protecting their financial interests while preserving the river’s ability to freely migrate across its floodplain and create aquatic habitat in perpetuity.

Landowners retain their rights to manage their acreage for agricultural production, irrigation, recreation, and more.

“The work that MARS is doing on the channel migration easements is one avenue that’s being taken to try and see if we can find properties and land owners who would be interested in dedicating that ground to be river bottom. That’s not to say they can’t use the land, the idea is that if the river marches over and starts to erode that land they won’t stop it. It’s potentially a national model for trying to strike that balance between a tame and wild river.”

— Karin Boyd, Applied Geomorphology

Supporting the best interests of Montanans and those of the landscapes we love

For millennia, our rivers have naturally shifted course across the floodplain, slowly carving and depositing historic sediment layers.  Called “channel migration,” this movement is vital for plants, wildlife, water quality, and an overall healthy ecosystem.

The Riprap Challenge

For property owners along the riverbanks, the erosion-deposit cycles of channel migration can range from headache-inducing to financially devastating, taking out their crops, structures, or spring creeks. Many folks try to mitigate erosion by armoring river banks — installing “riprap” in the form of boulders or concrete.

  • Riprap can slow erosion, but has negative consequences for fish populations, terrestrial wildlife, native plants, seasonal flooding, and water quality. Hard surfaces also tend to increase the speed of water as it passes — creating increased erosion downstream, and passing the problem from neighbor to neighbor.
  • Riprap is also an expensive temporary fix — costing up to hundreds of thousands of dollars to install and maintain.
Healthy Rivers for Native Habitat

Through a Channel Migration Easement, the conservation and agricultural value of the land through which the river flows is preserved in perpetuity, along with the continued health of habitats for fish, terrestrial wildlife, and native plants.

  • Vital riparian forests, which depend upon new sediments and open gravel bars, can colonize through seedlings which flourish in recently-disturbed areas.
  • Woody debris and fresh gravel, deposited along inside bends on the river, are critical for native fish to maintain healthy populations.
  • CMEs also benefit downstream neighbors and communities, who suffer less of the cumulative impacts of armored banks.
  • With native bank material and intact streamside vegetation, contaminants are filtered from runoff that would otherwise enter the river.
  • Should flooding occur, a spread-out floodplain will capture and slow down floodwaters, causing silts and other organic material to fertilize the soils which support agriculture.  The stored water will eventually return to the stream, helping to augment streamflow later into the year.
The CME model addresses the financial needs of landowners, while allowing us to leave a legacy of stewardship we can all be proud of.

Protecting the lasting health and vitality of critical riverside habitat

The Yellowstone River’s enduring health depends on its ability to shift its course across the floodplain — channel migration is critical for wildlife populations, native plant life, and water quality.

The CME model is a win-win — it protects landowner interests in their property’s value in exchange for simply allowing the river to do what a healthy river is supposed to do.

Through financial compensation, we incentivize landowner participation, rather than mandating it — a philosophy of mutual respect that aligns well with Montana values. This helps set a new paradigm for riverbank conservation work, and we hope to see its methods and benefits ripple across our state and the country.

Channel Migration Easements  FAQs

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What are CMEs?

Channel Migration Easements are a type of conservation easement that removes the property right of a landowner to channelize, harden, rip-rap, or stabilize the bankline and historic Channel Migration Zone in perpetuity in exchange for financial compensation. The landowner still maintains ownership of the land and retains all of the other property rights that are not explicitly limited in the easement. The purpose of a CME is to protect the river’s ability to move freely across its floodplain and allow it to adjust to changes in hydrology and bed load with erosional and depositional processes.

Can CMEs be donated or are they always purchased?

Yes, CMEs can be donated and in exchange, the landowner will receive a tax deduction based on the amount of money the property has depreciated as a result of extinguishing certain rights on the property. However, if the easement is donated, the entire parcel must be placed under easement (e.g., it is not recommended that the land owner consider subdividing land and donating only the Channel Migration Zone). If purchased, non-profits are restricted to paying no more than Fair Market Value of the landowner’s relinquished rights to use the property, which is based on a conservation easement appraisal.

How long will it take to complete a CME on my property?

This depends on a number of factors, including funding, and whether or not a Quiet Title Action is required (if the shape of your property has changed quite a bit then it is best practice to hire an attorney and establish certainty around land ownership). It usually takes at least 9-12 months for an appraisal, survey, baseline documentation report, and any other requirements the land trust may have (e.g., survey for environmental hazards, investigation of mineral rights).

 

What is the process of a CME?

Step 1: Interested landowners meet with MFP to discuss the program and the floodplain property being considered.

Step 2: An analysis of past river migration patterns is conducted, and the results are discussed with the landowner to identify potential easement boundaries and benefits.

Step 3: Specific easement and financial terms are discussed with all involved parties in an open process that acknowledges the needs of the landowner, MFP, and easement holder.

Step 4: The Channel Migration Easement is finalized, payment made to the landowner, and papers are filed at the County Courthouse. The easement is monitored over the long term, as prescribed by the agreed-upon terms.

How are the boundaries of CMEs determined?

CME boundaries are based on the Channel Migration Zone, a corridor that represents the most likely places that a large river will migrate based on the past 100 years. A CME boundary may include areas outside of the Channel Migration Zone, but this determination is based on the size and shape of the parcel, the available funding for purchasing the easement, and the land trust holding the easement.

The river has changed the shape of my property – how do I know what I own and what belongs to the state?

The state of Montana owns the bed, banks, and land below the ordinary high water mark of the river. That means that islands that have arisen out of the bed of the river over time through vertical accretion belong to the state. However, if the river avulsed (changed course abruptly) and cut off a piece of your land in the process, it may still belong to you. It is best to hire an attorney and seek the advice of a geomorphologist who can analyze a series of aerial imagery and give you an opinion.