bioretention_AaronVolkeningThe WDNR Standard 1004, Bioretention for Infiltration, has been revised and was available for comment from Wednesday, August 6th to August 27th.

Four changes have been drafted to be included in practice standard 1004, Bioretention.  A brief explanation of the changes are as follows:

  1. V.B.5.a.(3) – Specify a planting density of one foot on center. Dane County recommended this change, because consultants were trying to save money by spacing the plants too far apart.
  2. V.B.5.b. – Allow Class II erosion control mats to be substituted for shredded hardwood mulch or chips. Dane County recommended this change, because the wood chips float away when submerged.
  3. V.B.6.d.(5) – Increase the acceptable pH range of the soil mix from between 5.5 and 6.5 to between 5.5 and 8.0.  Jame (Sandy) Syburg with Purple Cow Organics, LLC in Oconomowoc, WI suggested the pH change.
  4. V.B.6.c. – Decrease the depth of the engineered soil mix from 3 feet to 2 feet.  This change was prompted by the results of research conducted in Neenah, WI by the Department and our many partners, such as the USGS and McMahon Engineers and Architects.

The justification for these four changes is outlined in the rest of the memo below.

If you have questions regarding the revisions of these practice standards, please contact Roger Bannerman at

Instructions to comment on standards: Submit your comments organized by section of the standard by deadline above. Keep comments specific and directly related to the standard. Indicate the section you are referring to when commenting, for example “V.B.4.: Does this mean that…” Respond in the same order as the sections appear in the draft. If you have general comments applicable to the entire standard please note them as such.

We prefer comments to be submitted online by using the “Comment” link located to the top left of this article or the comment section at the end of this article. Comments may also be submitted by email to or to preserve confidentiality.

WDNR will carefully consider all comments before finalizing an updated version of the practice standard.  All comments will receive responses from the WDNR. At the end of your online comment you may choose to receive an email update when any “replies” are received to your comment.

If you have questions about submitting your comments, the public comment period or our process contact Gini Knight at or (608) 441-2677.  Thank you for your input.