Published
When your dirt work touches a stream channel: the state permit from IDWR, not the county.
The rule, in the state’s own words
Almost every dirt job in this county answers to the county’s permits. Then there is the job where the ground itself answers to the state. The Idaho Department of Water Resources describes its jurisdiction in one sentence:
“The State Stream Channel Protection Act (Chapter 38, Title 42, Idaho Code) requires any person or entity altering the channel of a natural, continuously flowing stream to obtain a Stream Channel Alteration (‘SCA’) permit from the Idaho Department of Water Resources.”
— Idaho Department of Water Resources, SCA Statewide Permit Process Guidance Memo, February 13, 2024. Retrieved 15 September 2026
That memo is the department’s own processing guidance — published, dated, and statewide — and behind the sentence sits a statute with teeth: Idaho Code § 42-3803 requires a person to apply for and receive a permit before commencing any project or activity that will alter a stream. Not before finishing it. Before starting it.
Two governments, two permits, one job
The confusion this page exists to kill is the idea that one permit covers everything. They stack, and each answers a different question:
| Permit | Who issues it | What it asks about |
|---|---|---|
| Excavation and grading permit | Fremont County | The ground you disturb — acreage, slopes, floodplain blanks, the screening questions on the county page |
| Stream Channel Alteration permit | Idaho Department of Water Resources | The channel itself — work that alters the bed or banks of a natural, continuously flowing stream |
| Stormwater permitting at scale | EPA/DEQ track | Disturbance at one acre or more — a separate threshold, covered on the one-acre page |
The county’s permit does not substitute for the state’s, and the state’s does not substitute for the county’s. A culvert swap in a live creek can owe answers to both — plus, if a real structure is involved, the crossing standards on the bridge page.
What counts as a “stream channel”
The jurisdiction line is drawn by a definition, and the department quotes it in full:
“A stream channel is defined as a natural water course of perceptible extent with definite beds and banks which confines and conducts continuously flowing water.” — IDAPA 37.03.07.10.15
Every word does work. Natural — not a ditch someone dug; the roadside ditches on the drainage page are a different animal entirely. Continuously flowing — not a draw that runs for two weeks in June. Definite beds and banks — the water has made itself a shape. And the department adds one more rule that settles a lot of arguments: “The [stream] channel referred to is that which exists at the present time, regardless of where the channel may have been located in the past.” Where the creek used to run does not matter; where it runs now is what the permit attaches to.
What does not need the permit
The memo lists the situations where an alteration may not require an SCA permit at all. The ones that matter around here:
- Normally dry ground — a channel that in its natural state normally goes dry at the work site (a stream dried out by someone’s upstream diversion still counts as flowing, and so do flood channels of a continuously flowing reach)
- Work above the mean high-water mark — alterations outside or above the MHWM; the line the whole jurisdiction turns on
- Lakes and reservoirs — their beds are not stream channels under these rules
- Water-delivery upkeep — cleaning, maintaining, or repairing a diversion, canal, ditch, or lateral under a valid existing water right
- Debris removal without equipment in the channel — hand work, with the material hauled out where it cannot wash back in
Even here, note the memo’s quiet warning: the department reviews the application before saying “no permit needed,” and the filing fee is not refunded for having asked. The exemption is a determination you obtain, not a conclusion you announce.
The clocks and the fee
The timing rules are the ones project schedules actually break on:
| Clock | What the memo says |
|---|---|
| Application lead time | The Joint Application is submitted at least 60 days prior to the proposed construction start date |
| Filing fee | $20 per application — the application is not complete without it, and review does not start until it arrives |
| First response | Within 20 business days of a complete application, staff send a Notice of Initial Review — complete or incomplete, and whether the project is jurisdictional |
| Whole process | “In general, the total process should vary from 20 to 70 days or more.” |
Sixty days of lead time is the number to build a schedule around — it is written as a requirement, not advice. And “or more” is doing honest work in that last row: the total runs long when applications come back incomplete, plans miss the required details, or other agencies have comments.
What the plans have to show
Every application includes plans — vicinity map, plan view, cross-sections — and two features are non-negotiable: the stream boundaries and the mean high-water mark, drawn as they exist the day you file. Cross-sections cut through the greatest extent of the work, existing and proposed elevations, structures, construction limits. The MHWM is the jurisdiction line made visible: if there is a dispute about where it sits, the department may visit the site, may ask for a survey, and its final determination is the one that counts.
Who else gets pulled in
The Stream Channel Protection Act makes the department consult the agencies with an interest in the stream — fish and wildlife habitat, aquatic life, recreation, water quality are named in the statute. In practice the memo routes applications to the Lands department, typically Fish and Game and Environmental Quality on many projects, tribal and federal land managers where their ground is involved, and a courtesy copy to the Army Corps of Engineers. Neighboring landowners are notified when the work touches their property — including construction access and staging areas, which is a detail more than one project has learned the hard way.
Before any permit issues, staff work a published list of review questions: the purpose and necessity of the work, whether the proposal is a reasonable and permanent solution, whether it passes flows without harmful flooding or erosion up- or downstream, effects on fish habitat and turbidity, even the aesthetics of the reach. Riprap, culverts, bridges, and pipe crossings each have adopted minimum standards the design can follow. This is why the sixty-day lead exists — the review is substantive, not a stamp.
Running a stream job through it
- Decide what you are actually touching: continuously flowing water with definite beds and banks, below the mean high-water mark? That is the state’s lane.
- File the Joint Application at least 60 days before the proposed start — with plans showing stream boundaries and the MHWM as they exist now, and the $20 fee.
- Answer the Notice of Initial Review inside its 20-business-day window if more information is requested — silence can get the application returned.
- Let the agency comments happen: habitat, water quality, neighbors, land managers. They are part of the process, not an interruption of it.
- Keep the county permit conversation running in parallel — its grading application has its own floodplain and slope questions to answer.
- Build to the permit’s conditions and the minimum standards, and keep the paperwork with the project records.
- Planning work near water in Island Park? Bring the questions to a crew that already knows the order of the paperwork — (208) 932-1140.
Common questions
When is IDWR the permitter instead of the county?
When the work alters the channel of a natural, continuously flowing stream — definite beds and banks confining continuously flowing water. The Stream Channel Protection Act puts that permit with the Idaho Department of Water Resources, and the county's grading permit does not substitute for it.
How early must the stream application be filed?
At least 60 days before the proposed construction start date, on the Joint Application form. The memo states it as a submission requirement, not a suggestion.
What does a Stream Channel Alteration application cost?
A $20 statutory filing fee per application. The application is not complete without it, staff review does not begin until it is received, and it is not refunded even if the department determines a permit is not required.
How long does the SCA permit process take?
The department's own guidance says the total process should generally vary from 20 to 70 days or more — longer when information requests go unanswered or agency comments require changes.
What is the mean high-water mark, and why does it matter?
It is the boundary line the state's jurisdiction analysis keys on — it must be shown on the application plans. Work above or outside the MHWM may not need a permit; work below it in a continuously flowing stream does. If its location is disputed, the department can visit the site, require a survey, and its determination is final.
Do irrigation ditches and roadside ditches need this permit?
Generally no on both. The rules define a stream channel as a natural water course with definite beds and banks conducting continuously flowing water — constructed ditches are not it, and cleaning or maintaining diversions under a valid existing water right is listed as not requiring a permit.
Does replacing a culvert in a live creek need an SCA permit?
If the work alters the channel below the mean high-water mark of a continuously flowing stream, yes — culverts and bridges are among the activities the rules address, with adopted minimum standards the design can follow. The Joint Application even has a block for the size and flow capacity of the bridge or culvert.
Which other agencies get involved in an SCA application?
The statute requires consultation with state agencies interested in the stream — the memo names the Lands department, Fish and Game, and Environmental Quality as typical, plus land-management agencies where their ground is involved, notice to adjacent landowners whose property is used, and a courtesy copy to the Army Corps of Engineers.
Can work start while the permit is pending?
No. Idaho Code § 42-3803 requires a person to apply for and receive a permit before commencing any project or activity that will alter a stream — the sequence is file, obtain, then build.