Construction & Materials

If a contractor has a question whether something had been pursued and denied, they need to post the question on BIDX.

Contractors must bid projects based on all the contract documents. If the contract documents (i.e., permits) do not state something is approved, the contractor can pursue a request to the regulatory agency for their own additional approvals (refer to Iowa Department of Transportation's General Specifications 1107.18 Environmental Protection).

Any permit approvals obtained by the contractor postletting, after award of contract and signing, would not be subject to value engineering, as long as it does not involve a change to the plans. The postletting permit approvals must be confirmed in writing from the regulatory agency and will be accepted by the Iowa Department of Transportation.

It is not possible for the Iowa DOT to submit all the potential methods for permit approval because this is dependent on the contractor's means and methods. The Iowa DOT will ensure that there is at least one method that can be used to ensure the work is constructible.

Temporary stream access is detailed in Standard Road Plan EW-401.

The term ordinary high-water mark means a point on a streambank or shoreline at which the presence and action of surface water is so continuous as to leave a distinct mark below which vegetation and soil is noticeably different from the top of the streambank or shoreline. This mark is typically recognized by the presence of a clear line below which vegetation cannot grow due to the presence of surface water, but can also be identified by other physical characteristics within the stream channel, including the presence of litter and woody debris (e.g., corn stubble, leaves, tree branches and/or limbs), or erosional features, such as shelving, scour holes, and sediment.

Sandbars and vegetation bars within the stream channel are generally considered to be below the ordinary high-water mark.

Not at this time, but this will be further reviewed for consideration in the future.

Not at this time, but this will be further reviewed for consideration in the future.

For some projects the Iowa Department of Transportation will hold possible constructability meetings and/or pre-bid meetings for discussion of the project and to received input from the construction industry.

Copies of permits are now available on the Iowa DOT's web site at: Section 404 permit Library

If Iowa Department of Transportation determines that dredging is essential to construct the project, then the Iowa DOT will pursue approval of dredging in the 404 permit application. This typically includes dredging inside cofferdams, barge slips, removal of sand bars to improve water flow, etc.

If the Iowa DOT determines that dredging in the project area is not allowed, due to environmental or other concerns, then the Iowa DOT will include a Standard Note 282-2 in the plans clearly stating that dredging of any type is not allowed and the reason why.

When not specifically disallowed by the Iowa DOT, contractors may elect to pursue their own approvals for the use of dredged materials, provided those approvals are in accordance with Articles 1107.18 and 1106.07 and there are no environmental concerns. Elective items typically include the use of dredged materials for causeways constructed according to Standard Road Plan EW-401, work pads, etc. The Iowa DOT will inform contractors of relevant information about stream conditions as much as possible based on specific questions provided via BIDX. Please note that Iowa DOT obtains approval for temporary structures constructed according to Standard Road Plan EW-401, but not for the source of materials used within those structures.

In general, 404 permits require that materials excavated/dredged from the stream be removed to upland, non-wetland locations when no longer necessary for construction of the project.

In the 404 permit and in Iowa Department of Transportation's General Specifications 1107.18 and 2547. A contractor is permitted to do construction that is authorized by the 404 permit. Because the permit contains conditions that may affect construction methods, it should be reviewed by the contractor before the work is performed.

The Iowa DOT’s Office of Contracts can provide a copy of a project’s 404 permit upon request.

No, unless the dredging or stream excavation is a required element of the contract documents. If included in the contract documents, dredging or stream excavation would be authorized by Iowa Department of Transportation’s 404 permit.

When not a part of Iowa DOT’s 404 permit or contract documents, a contractor may, at his own discretion and his own expense, apply for a 404 permit to dredge or excavate the stream. Contractors should be aware that this process may take months and will not be paid for by the Iowa DOT.

No. The Iowa Department of Natural Resources requires that materials used for temporary stream crossings or work pads be removed to an upland area within 30 calendar days of no longer being needed.

The soil material excavated from a cofferdam must be removed to an upland area. If stockpiled for later use, the material must be stored in a manner that it will not erode into streams, water bodies, or wetlands.

Once cofferdam construction is complete, the cofferdam should be backfilled in accordance with Iowa Department of Transportation's General Specification 2405.02. The material originally excavated from the cofferdam may be replaced as backfill.

The 401 permit is issued by the Iowa Department of Natural Resources under Section 401 of the Clean Water Act. The Iowa DNR’s 401 certification authorizes construction of the project and provides special conditions that must be followed.

The 404 permit is issued by the U.S. Army Corps of Engineers under Section 404 of the Clean Water Act. This also authorizes construction and provides special conditions. The Iowa Department of Natural Resources' 401 certification is incorporated into and becomes a part of the "‘404 permit".

Nationwide permit 14 provides for the construction or improvement of linear transportation projects, such as highways and bridges.

Nationwide permit 33 provides for temporary stream crossings and works surfaces, such as causeways or work pads.

Nationwide permit 13, Streambank Stabilization, provides for streambank shaping and riprap placement. Nationwide permit 3, Maintenance, provides for repair or replacement of existing infrastructure damaged by storm activity.

Standard Road Plan EW-401 provides for the basic design of temporary stream crossings, causeways, and work pads used with Iowa Department of Transportation projects. EW-401 has been preapproved by the regulatory agencies and is covered by Iowa DOT’s 404 permits.

Alternative methods of constructing stream crossings and work pads are not generally approved in contract documents or 404 permits, unless specifically stated. Contractors wishing to use alternative methods may, at their own discretion and expense, apply for a 404 permit to authorize an alternative stream crossing. Contractors should be aware that this process may take months and will not be paid for by the Iowa DOT.

Some requirements will be listed in the 404 permit. Other requirements include 1) the material must be clean (meaning 10 percent or fewer fines passing the #200 sieve), and 2) the activity must be approved in a 404 permit.

For hydraulic dredging in the Missouri River, the contractor is required to perform elutriate testing in accordance with Iowa Department of Natural Resources guidelines'. Hydraulic dredging in other rivers in Iowa does not have this requirement. Mechanical dredging has no additional special requirements.

An ordinary high-water mark is a line on the shore established by the fluctuations of water and indicated by physical characteristics, or by other appropriate means, that consider the characteristics of the surrounding areas (see 33 CFR 328.3(e)).

Ordinary high-water mark may be recognized in the field by a number of characteristics, including a pronounced scour line on the streambank or the lower limit of permanent vegetation. Normally, the ordinary high-water mark is that line on the bank or shoreline that has vegetation growing above and bare soil below.

The size of pipe and number of pipes is to be determined by the contractor. In accordance with Standard Road Plan EW-401, the pipes must be sized to not restrict expected high flows or prevent the movement of aquatic life. It is the contractor's responsibility to size the pipes depending on the field conditions to meet the requirements of the regulations.

In the future, floating silt curtain (Standard Road Plan EC-202), will be required whenever a temporary crossing or work pad is constructed according to Standard Road Plan EW-401. The purpose is to prevent sediment pollution that may be harmful to aquatic life during the installation or removal of temporary crossings or work pads. The engineer should be consulted if field conditions prevent installation of floating silt curtains.

The Iowa DOT will notify contractors when this requirement has been put into effect.

This would depend on what was allowed by the regulatory agencies in the 404 permit. Other methods may include temporary bridges, work from barges, barge slips at shoreline, or other methods involving little or no impacts to rivers or streams.

The Iowa DOT's General Specifications 2547.

Yes. In accordance with Iowa Department of Transportation's General Specifications 2547, revetment that has been removed may be incorporated elsewhere in the project provided it meets the specification for the intended final use.