As discussed during the February 3^rd Municipal Engineers Meeting, attached is the proposed DuPage Rapid Assessment Method for Critical Wetland Evaluation that is referenced in Article 11.

DuPage Rapid Assessment Method for Critical Wetland Evaluation

For Stormwater Management, comments have been received from March through August 2010 regarding removal rates and efficiencies, the first flush or Water Control Volume, BMP selection, and the recommendation that a fee-in-lieu option be considered. The draft ordinance proposes 80% TSS removal for new development and 40% TSS removal for redevelopment. A variety of BMPs will be available to meet these requirements so that the best combination of BMPs can be chosen for the site and receiving waters. For the DuPage County Ordinance Update, a Water Control Volume will be required and will depend on the impervious area of the site. BMPs may provide any of the required Water Control Volume. The Water Control Volume will be calculated as the product of the applicable impervious area and the specified rainfall depth. These factors vary by development size and type. The Water Control Volume will be held onsite for infiltration or evapotranspiration, or released over 48 hours where the soils are inappropriate. For smaller sites, it is proposed that the 100 year detention requirement be eliminated in order to balance the costs of stormwater infrastructure. A fee-in-lieu program is being considered for water quality BMPs.

For Wetlands, comments have been received regarding riparian buffers, riparian habitat, manmade wetland requirements, temporary impacts and restoration to wetlands, wetland delineation, and critical wetland definition.

• Given that riparian areas are a form of buffer, riparian buffers will be combined with wetland buffers since it makes more sense to regulate all buffers under one section of the ordinance instead of having two sections which would nearly mirror each other.
• Wetland buffers are 50 and 100 feet.  We selected 50’ because that is comparable to a regulatory wetland buffer.  If a stream has critical wetland associated with it then a 100’ buffer would apply.  Buffers of wider widths become more of a land use or tree protection issue.  Based on research, the greatest effectiveness is in the 50-100’ range.  Widths greater than that have a diminishing return of effectiveness as compared to the constraint placed on development of the land.
• The jurisdiction of wetlands will follow the Clean Water Act.  If an area is abandoned and it converts to wetland regardless of how it came to be it would be regulated.  If the area is a constructed facility that has not been abandoned and requires maintenance, for example, that would be allowable.  If an area is desired to be filled that has not been abandoned and all other aspects of the Ordinance can be met, then the area could be filled as it would not be a regulated area.
• Critical wetlands status will be applied using either the wetland Qualitative Value, the Floristic Quality Index, or the existence of endangered species.
• Temporary wetland impacts will be restored in place to existing conditions such that they are capable of and FQI no lower than that of the original wetland within 2 years of restoration.
• Wetland delineation shall be performed by a DuPage County Certified Wetland Specialist.

For Floodplains, comments have been received regarding accessory structures in the floodplain. It is recommended in the proposed ordinance draft that accessory structures to single family residences, such as detached garages, attached garages, and sheds, may be constructed with the lowest floor at or above the BFE.

For Permit Application and Review Process, comments have been received regarding the review procedure, specifically the fee structure, submittal requirements, and self or 3^rd party certification. The draft ordinance will have different requirements for different types of development.

We have provided revisions of the wetland and buffer sections of the ordinance to the subcommittee members for review.  A main remaining issue within this draft is regarding riparian areas.  This draft provides protection under the buffer section to areas that would have previously been protected under the riparian section of the current ordinance. Additionally, this version proposes a maxim width of the linear buffers of 50’, whereas the previous ordinance only limited the riparian width to the width of the flood plain.  There has been much discussion on this issue of width and the group is looking for feedback to work towards a consensus.  The questions is whether to leave the width as determined under the current Ordinance, or set a maximum width as currently written.  Though it is possible that a different maximum width could be used.  Or to have maximum widths based on the tributary area, a sliding scale.  If you have the opportunity, please provide us with your thoughts on this issue.

While the Steering Committee is not in consensus yet on all issues, we are posting the most recent version of the draft changes regarding wetlands , riparian environments and buffers in order to let all see where the discussion is at now, and to participate through the review and comment process.

Draft Wetland Ordinance V5.3