# Title 89 — Water Commission

## Article 89-14 — Public Highway Stream Crossings

## Chapter 89-14-01 — Stream Crossing Design

### § 89-14-01-01. Standards.

Except as provided in section 89-14-01-06, all highways constructed or reconstructed by the
department of transportation, board of county commissioners, board of township supervisors, their
contractors, subcontractors, or agents, or by any individual, firm, corporation, or limited liability
company must be designed to meet the standards contained in this chapter. The department of
transportation, board of county commissioners, board of township supervisors, their contractors,
subcontractors, or agents, or any individual, firm, corporation, or limited liability company that fails to
comply with these standards is not entitled to the immunity provided in North Dakota Century Code
sections 24-03-06, 24-03-08, or 24-06-26.1.
History: Effective May 1, 2001; amended effective July 27, 2001; January 1, 2015.
General Authority: NDCC 24-02-01.1, 24-02-01.5, 61-03-13
Law Implemented: NDCC 24-03-06, 24-03-08, 24-06-26.1
### § 89-14-01-02. Definitions.

1. "Constructed" means to construct a new highway on a new location or corridor.
2. "Highway, street, or road" is defined in North Dakota Century Code section 24-01-01.1.
3. "Reconstructed" means to regrade, add a lane adjacent to the existing alignment, or do full
depth road surface replacement on an existing highway location. For purposes of this chapter,
reconstructed also includes replacing or installing a stream crossing.
4. "Stream crossing" means an opening to permit the flow of water under, adjacent to, or
because of a highway.
History: Effective May 1, 2001; January 1, 2015.
General Authority: NDCC 24-02-01.1, 24-02-01.5, 61-03-13
Law Implemented: NDCC 24-03-06, 24-03-08, 24-06-26.1
### § 89-14-01-03. Design flood frequency.

The following table provides the minimum design standard recurrence interval of the event for
which each type of stream crossing must be designed. Nothing contained in this chapter is intended to
restrict an entity from providing greater capacity.

State Highway System County
Urban System Rural System Rural System
Type of Urban Principal Arterial Minor Major Major Off4
Crossing Regional Roads Interstate Other Arterial Collector Collector System
Bridges & 25 year2 25 year2 50 year2 50 year2 50 year2 25 year2 25 year2, 3 15 year2, 3
Reinforced
Concrete Boxes
Roadway 25 year2 25 year2 50 year2 25 year2 25 year2 25 year2 25 year2, 3 15 year2, 3, 5
Culverts
Storm Drains 10 year1 5 year1 10 year2 10 year2 10 year2 10 year2
Underpass Storm 25 year1 25 year1 50 year2 25 year2 25 year2 25 year2
Drains
1Discharges must be computed using the rational method or other recognized hydrologic methods.
2Discharges must be computed using United States geological survey report 2015-5096 or other recognized hydrologic
methods.
3If an overflow section is provided, the pipes and the overflow section, in combination, must pass the appropriate design
event within the headwater limitations provided in this chapter.
4Off system roads include all nonmajor collector public roads open for public travel.
5For public roads open for public travel under the jurisdiction of a board of township supervisors of a civil township, the
recurrence interval is 10 years.
History: Effective May 1, 2001; amended effective July 27, 2001; January 1, 2015; January 1, 2023;
July 1, 2024.
General Authority: NDCC 24-02-01.1, 24-02-01.5, 61-03-13
Law Implemented: NDCC 24-03-06, 24-03-08, 24-06-26.1
### § 89-14-01-04. Floodplain consideration - Upstream development.

All stream crossings must comply with applicable floodplain regulations and regulatory floodway
requirements per North Dakota Century Code chapter 61-16.2. If a stream crossing is being replaced
and buildings or structures are located upstream from the crossing, the stream crossing must not be
reconstructed in a manner that increases the likelihood of impacts to those upstream buildings or
structures, even if the capacity of the crossing being replaced was greater than the capacity otherwise
required by this chapter. Any stream crossing constructed as part of a newly constructed roadway must
be constructed to pass the federal emergency management agency identified one-percent annual-
chance flood event flow without the resulting increase in headwater impacting any existing buildings or
structures. Structures, for the purposes of this section, include grain bins, silos, feedlots, and corrals.
Structures do not include pasture fencing.
History: Effective May 1, 2001; amended effective January 1, 2015; January 1, 2023.
General Authority: NDCC 24-02-01.1, 24-02-01.5, 61-03-13
Law Implemented: NDCC 24-03-06, 24-03-08, 24-06-26.1
### § 89-14-01-05. Allowable headwater.

The allowable maximum headwater when passing the design discharge must be measured from
the bottom of the channel. For arch pipes, the maximum allowable headwater must be based on the
rise of the pipe, and the pipe size category must be the equivalent round pipe size. For multiple pipe
installations, the pipe diameter used to calculate the allowable headwater must be the diameter of the
largest pipe. Tailwater resulting from downstream conditions, either natural or manmade, must be
accounted for in the determination of the crossing's capacity and the resulting headwater. Additional
guidance is provided in the North Dakota department of transportation design manual. If a crossing
results in less than one-half foot [15.24 centimeters] of headloss when passing the appropriate design
discharge, this section does not apply.

Streambed Slope
(feet/mile) Pipe Size Allowable Headwater
<5 24" - 54" pipe diameter + 2 feet
≥ 60" 1.5 pipe diameters
5 to 10 24" - 36" pipe diameter + 2 feet
42" - 54" 1.5 pipe diameters
≥ 60" 2 pipe diameters
>10 ≥ 24" 2 pipe diameters
History: Effective May 1, 2001; amended effective January 1, 2015.
General Authority: NDCC 24-02-01.1, 24-02-01.5, 61-03-13
Law Implemented: NDCC 24-03-06, 24-03-08, 24-06-26.1
### § 89-14-01-06. Deviations.

The board of county commissioners, board of township supervisors, their contractors,
subcontractors, or agents, or any individual, firm, corporation, or limited liability company may deviate
from the standards contained in this chapter if the deviation is approved in writing by the department of
water resources and the department of transportation. A request to deviate from the standards must be
made in writing and must set forth the reasons for the proposed deviation. The department of water
resources and department of transportation may grant a deviation for good and sufficient cause after
considering public safety, upstream and downstream impacts, and other relevant matters.
The department of transportation may deviate from these standards if the department determines it
is appropriate to do so and the crossings are designed under scientific highway construction and
engineering standards. The basis for the department's decision must be documented in writing.
Roads constructed as part of a surface coal mining operation for use solely as part of the mining
operation are not subject to the requirements of this chapter. Roads constructed because of a surface
coal mining operation for use by the public are bound by the requirements of this chapter, but
deviations may be requested under this section.
History: Effective May 1, 2001; amended effective January 1, 2015; January 1, 2023.
General Authority: NDCC 24-02-01.1, 24-02-01.5, 61-03-13
Law Implemented: NDCC 24-03-06, 24-03-08, 24-06-26.1
