Promoting uniformity of urban design and construction across Iowa.


Seed Shortages and Substitutions

Due to continued anticipated shortages of specified seed types, Iowa DOT’s Roadside Development and the Construction & Materials Bureau has recommended allowable changes to the DOT’s seed mixes as follows for the 2023 construction season.

Permanent Rural mix due to the anticipated shortage of Perennial Ryegrass (Linn):

2601.03, C, 3, b, Seed Mixture.

Add note to Table 2601.03-3 (SUDAS Table 9010.07):

  1. For 2023 construction season only, ryegrass rate may be reduced to 30 pounds per acre as long as the fescue rate is increased to 150 pounds per acre.

Permanent & Stabilizing Urban mixes due to the anticipated shortage of Creeping Red Fescue:

2601.03, C, 2, b, Seed Mixture.

Add note to Table 2601.03-2 (SUDAS Table 9010.06):

  1. For 2023 construction season only, a partial or full substitution of the required 25 pounds of Creeping Red Fescue is allowed with any of the following varieties:  Chewing Fescue, Hard Fescue, Sheep’s Fescue or Blue Fescue.

2601.03, C, 4, b, Seed Mixture.

Add note to Table 2601.03-4 (SUDAS Table 9010.06):

  1. For 2023 construction season only, a partial or full substitution of the required 25 pounds of Creeping Red Fescue is allowed with any of the following varieties:  Chewing Fescue, Hard Fescue, Sheep’s Fescue or Blue Fescue.

Asphalt Binder and Mixture Reference Guides

The Asphalt Paving Association of Iowa has updated their reference guides. The reference guide for local agencies was developed to assist with selection of asphalt mixes for local agency projects. The reference guide for Iowa DOT provides updated guidance for projects constructed under Iowa DOT requirements.

2023 Edition Revisions are Posted!

The 2023 editions of the SUDAS manuals are posted. Remember, we do not print and mail revision packets. Electronic versions of the revision packets can be found under Design Manual -> Latest Design Revisions or Specifications Manual -> Latest Specifications Revisions.

The current editions of the manuals have also been updated.

Iowa DNR Review

The Iowa DNR Water Supply Engineering Section conducted a review of the 2023 Edition of SUDAS Specifications Divisions 3 and 5. In a letter addressed to SUDAS staff, Iowa DNR stated “at the current time, they are in accordance with the design standards of this Department and will be filed accordingly.” Click here for a copy of the letter.

Iowa DOT Working Day Charging Changes

The construction industry requested removing working day charges for Saturdays.  Iowa DOT management approved this request. Click here for more information. Note – SUDAS Specifications Section 1080, 1.06, B, 2 already provides for not charging the contractor for working on Saturdays, unless a mandatory six-day work week is specified.

General Permit No. 2 Proposed Updates

Iowa DNR has drafted updates to General Permit No. 2 for 2023 to 2028.  Major updates include:

  • Clarify that seeding alone is insufficient to stabilize a site and that establishment of vegetative cover sufficient to preclude erosion is necessary to achieve stabilization.
  • Clarify that other stabilization measures must continue to be implemented when necessary until seeded areas have achieved sufficient vegetative cover.
  • Clarify that the definition of “final stabilization” includes areas covered by a permanent structure

All the changes may be found here:

Water Main and Sewer Separation Requirements

Effective March 16, 2022, 567 IAC 43.3 (2)“a”(3) was updated to replace subparagraph (3) with new subparagraphs (3) and (4) to allow for added flexibility for water main project design with regards to separation from sanitary and storm sewers. Click here for more information from the DNR. Click here to see the supplemental revisions for SUDAS.

Public Works Service Bureau

SUDAS staff has created the Iowa Public Works Service Bureau (PWSB). The PWSB provides a resource for public works staff members from cities of all sizes to connect with and learn from others how best to improve work efficiencies, learn new techniques, and maximize available resources.  Our goal is “communicate to innovate!”

Register as a member on the site. Once registered, you can view the information we only share with registered users, such as our reports, forums, and contact information for your fellow members. Check out our latest newsletter for more information, and visit us on FacebookTwitter, and LinkedIn

Modifying the SUDAS Manuals

If you need to modify the SUDAS manuals to meet your jurisdiction’s needs, please read this document first.

SUDAS Email List

Anyone who would like to receive emails from us can subscribe to our list.

Temporary Traffic Control

SUDAS staff developed an updated Temporary Traffic Control Handbook through an Iowa Highway Research Board project. If you would like to request a copy, please complete this form. Click here for an electronic version of the handbook.

Potential Errors

If you notice something within the SUDAS Manuals that appears to be an error, please contact Beth Richards ( and let her know.