• Countersink culverts six inches for waters of the US.
• Generally done in response to environmental considerations.
• Instream relocation/restorations, fish ladders, fish weirs.
• Standard bridge crossings with AOP considerations.
• Step-pool design downstream of highway bridge.

• Endangered Species
• Generally, we would limit use of riprap per agency consultations.
• No anadromous species in the state, have not designed for this.
• No specific organisms specified. Endangered/threatened species are examined more closely.
• Primarily focused on fish passage but have done some work for reptiles (turtles/snakes) and general “small critter passage.”
• The check boxes vary in programs.
• Threatened species.

• Annual Exceedance Probability
• AOP typically sized for low flow scenarios.
• As stated previously, we are currently working on policy guidance but in the past, we have incorporated elements from HEC-26 and stream-simulation methods
• Based on a geomorphic approach
• Bury culverts, backfill with in situ material. This is appropriate for our sites and AO.
• Countersink culverts six inches for waters of the US.
• Crossings for Waters of the US or Waters of the State, a sump is required per design manual to provide a natural bottom to facilitate AOP.
• Culvert hydraulic properties only
• Culvert openings based on % of bankfull width depend on stream type. Culverts imbed 1’ below natural channel bottom.
• Generally, we would limit use of riprap per agency consultations.
• HEC-26 referred.
• Size all structures on intermittent and perennial streams at least as wide as bankfull width. Interior bank materials are sometimes placed. All 4-sided boxes and some pipes are embedded according to HEC-26. Material excavated during the construction of the structure is used to backfill the embedment area.
• Size structure to maintain low flow depths and velocities; use benching, sills, and baffles to maintain bed materials and approximate natural channel conditions.
• Sizes the AOP based on bankfull width does not include interior placed bed materials.
• The state position has been that the culvert design should fit the needs of the site.

• HEC-26.
• Most grade controls are generally considered impediments and will not receive permits/approvals.
• None.
• None.
• Note that the state has limitations on where bioengineering techniques are allowed. In general, these techniques are considered on a site-by-site basis and usually limited to locations that are not meant as scour/erosion countermeasures to critical infrastructure, but rather habitat enhancements. For example, root wads might be considered upstream or downstream of a bridge, but within the bridge zone the “bioengineering” treatment might be riprap with backfill to promote the restoration of riparian functions and values.
• Nothing specific.
• Some of these are quite rare.
• Top checkbox is all correct except for shape, we have not yet designed for shape beside trapezoidal channel.

• Bury culvert bottom 1 foot to allow natural channel bed to re-establish.
• Bury the bottom of culverts to allow for natural stream bed.
• Downstream weirs did not work well where it was tried. Probably not functional.
• Replace pipe with Open-Bottom ARC Culvert.
• Use of supplemental pipes or high-flow structures to accommodate large events while maintaining more natural low flow characteristics in the primary bridge/culvert.
• We do not typically retrofit existing culverts as they are under sized. If they are sized appropriately then we will perform rehabilitation measures based on the natural condition.
• We have experimented (with limited success) trenchless technologies for culverts in deep fills. Our Northern Region and Central Region hydraulics staff would be the appropriate contacts for insights on those efforts.

• AOP not included in prioritization.
• As projects are developed, we are trying to implement a process of evaluating AOP and reference USFWS roadways as fish passage barriers GIS Map https://aquaticbarriers.org/explore/
• Current policy dictates that a structure will not be replaced for AOP reasons alone. Unless outside funding (trout unlimited, DNR, etc.) is provided, a structure must be scheduled for replacement (based on condition) in order to improve AOP at a given site. That said, when prioritizing for AOP severity of barrier, magnitude of reconnected stream miles, and species of concern (trout, salmon) are all factored into the decision-making.
• Documented fish presence, the length/extent of habitat upstream, cost (e.g., deep fills tend to dissuade planners from including an AOP project in a corridor improvement project), state priorities, leveraged funds from others (tribes, NGOs, USFWS, NMFS), and to some extent proximity (i.e., bundling projects into one project for cost benefits).
• Done as part of a CIP project.
• None.
• State Parks and Wildlife directive.

• It is often the case that the manufacturer will send out a representative to observe/coach on the installation. Often, there are tricks-of-the-trade that come with experience. (For example, a contractor might use a magnet for bolting up a structural plate pipe in place along the invert. You can “lift” the fastener up through the holes using a magnet.) Other contractor means and methods approaches are very specialized, such as the use of spreader bars with a crane during installations.
• The state DOT provides training for inspectors.

Responses to Other:

• All construction projects require a QA/QC assessment by Environmental personnel that includes a review of the construction of AOP structures.
• All the points above have been implemented at one time or another, but not universally. Our technical staff tends to be very busy and is a large state. It can be very time-consuming to travel to project sites. Future use of real-time remote meeting tools (e.g., Teams via Starlink, drones, etc.) may improve engagement in remote areas over time.
• AOP aspects of projects have not demanded a specific focus during construction.
• Developing process to assess AOP at water crossings, currently in progress at the DOT.
• Fairly new for us so none of these currently apply.
• Feedback loop to ensure designs are buildable, e.g., embedment material provision for interstitial material and for providing pay item quantity. The field coordination and on-site engagements are case-by-case for critical installations.
• N/A.
• None of the above.
• None.
• Representatives at natural resources agencies review meeting, regular and early coordination with fisheries agencies.
• State DOT and DNR have identified the importance of communication from the design team to the construction team (both contractors and DOT field personnel). This would be in the form of identifying special AOP design features within contract documents and discussing them at preconstruction and regular construction meetings through the life of the project so that unintended adjustments are not made. Involvement of the regulatory agencies to this point has varied by project based on the criticality of the resource.
• Unknown.
• Unsure.
• Utilize separate contractor that specialize in this work.

• Also, CMGC and other alternative delivery methods.
• AOP consideration is part of standard design practice for all projects that include stream crossings.
• AOP is not the primary focus of any projects. AOP is included in other projects.
• CMGC is popular choice for our DOT.
• CMGC.
• Depends on project.
• Detail-Build.
• N/A.
• Progressive Design-Build.
• Require countersinking for waters of the US.
• Usually part of scheduled CIP project.
• We don’t typically deliver projects specifically for AOP purpose only.

• AOP-specific monitoring is not generally performed for most projects but may be done at locations where there were specific concerns or issues related to AOP being addressed.
• As required by permit.
• Post-construction monitoring only occurs when regulatory agencies require monitoring. This is not typical on construction of structures alone. The construction of some of the structures is audited by agency personnel.
• This tends to be an activity that occurs as the opportunity arises. While we are interested in starting a culvert asset management program that includes AOP condition assessments, and we have published a research paper that provides a framework for such a program, we currently do not have funding or staffing to implement it. Given the size of the state, staff may stop at culvert sites as they are passing by for other projects. The Department of Fish & Game has its own culvert condition tracking staff, and they publish an online map showing preliminary fish passage assessment information. (Further analysis may refine those conditions, but the F&G assessments are useful for broad brush tracking).

• Varies, varying by location, size (i.e., NBIS?), “criticality” (to borrow from the federal flood risk management standard language), etc. There are also permit stipulations that may apply, particularly if there are complex design features or habitat objectives.

• Culvert injunction.
• Don’t have a specific AOP monitoring program; inspections are primarily related to structure condition and occur on a 2yr cycle for larger pipes and other structures.
• None.

• Natural resource management section is currently working to develop a program that considers safety, increased resiliency and landscape (terrestrial and aquatic) connectivity.
• State DOT recognizes the secondary benefit, but it does not influence the prioritization.
• We are sometimes asked to provide moose passage accommodations!
• We do not prioritize/fund projects based on AOP.
• We don’t specifically fund AOP projects solely. AOP is considered when replacing existing structures due to age and condition.
• We generally don’t have projects that are specifically to address AOP.

• We are hoping to implement a statewide asset management program eventually. Presently, our regional hydraulics staff maintain independent records of culverts within their respective jurisdictions, though some of this information is available on the statewide GIS platforms.

• Consults with agencies.
• DNR, State Department of Environmental Management and USACOE.
• Have had occasional discussions with Nature Conservancy.
• Local Agency.
• Local City Agency.
• N/A.
• No.
• None.
• None.
• Note these are not AOP-specific projects.
• Universities.
• Unknown.
• Working to partner with other state agencies and possibly local water groups.

• Bridge hydraulics and environmental.
• Bridge office, hydraulics staff, and environmental stewardship office staff.
• Bureau of Structures and Bureau of Project Management.
• Dedicated program and design staff.
• Environmental and bridge.
• Environmental Services Section supports design by addressing requirements, monitoring if needed.
• Environmental Services Section.
• Environmental, Hydraulics.
• Environmental, Regional Coordinators.
• Environmental.
• Environmental.
• Hydrology, Design, Natural Resource Management sections.
• Our regional hydraulics engineers are responsible for AOP designs in culverts and overseeing the technical aspects of consultant work products; the statewide hydraulics staff are responsible for bridges, which tend to be favorable for AOP.
• The Hydraulics Unit, Environmental Permitting Unit, Division Environmental Officers.