Application of the ordinance as currently written to typical roadway projects has proved challenging over the last 18-years.  Publicly maintained roadways are generally in land holdings that reflect the absolute minimum land necessary to accomplish the primary mission of transportation.  As is often pointed out by those charged with that mission, “the purpose of a transportation project is not stormwater management”.   In this day and age, however, no responsible public official suggests that transportation projects can, or should, ignore stormwater impacts.  We do though need to evaluate our approach to stormwater management for public roadways and make sure we get maximum benefit from the infrastructure and tax dollars available to build and maintain it.

A workable application of the current Ordinance has relied heavily on interpretation and intent.  A sub-group of the Steering Committee met recently to discuss roadways, and more broadly “linear Transportation Projects” in the context of the Ordinance update, and has a few recommendations that will begin our discussion.

• As we have been discussing throughout this Update, keep the focus on Impervious areas, and changes to impervious areas.
• The changes in impervious surfaces from a roadway project should not cause an increase in flood flows from the right-of-way.   This is within the control of the roadway agency, and is a different case than the flow from a cross culvert draining areas through the Right-of-way.  Often, an undersized cross-culvert turns the roadway into a low-level dam.  The dam attenuates peak flows downstream by “backing up” flood water.  Just like a dam, at some event the roadway will overtop, which can cause “traffic damages” in the form of delays and slowed emergency response, and sometimes even more hazardous conditions.  So what are the options?  If the size of the culvert is increased, is it the roadway agencies responsibility to create a flood control reservoir to mimic action of flood attenuation of the undersized culvert?  Different jurisdictions have answered that question differently, but the implications of that answer are enormous for roadway agencies who own very limited land.  Very often, a “problem culvert” becomes an institution because of the inability to replace the “dam effect” elsewhere than at that culvert.  While no specific recommendation is offered, the issue needs to be further discussed.
• Roadways are key factors in the pollutant loading to a stream, and like all impervious surfaces a contributor to the total runoff volume.  Would it be a better focus of the funds spent on stormwater management for roadway projects to require that the “Water Quality Control Volume” be addressed (see earlier post for a discussion)?  One of our conclusions in the subgroup was that if we could get strict compliance with the “Water Quality Control Volume”, and the changes to impervious area did not increase discharges, we don’t really need roadway stormwater infrastructure to do much else except of course drain the road.
• Simple engineering applications, like the unit area detention nomagraph already used for roadway projects, are usually as technical as we need to get for the limited real impact roadways have.

So, what are your thoughts on roadways?

We have posted before regarding an approach to integrating water quantity regulation with water quality regulation.  We have reviewed other programs nationally and surveyed the literature and trends in this regard, and believe that designating a “water quality control volume” would meet the goal of integrating the Counties strong water quantity regulatory program with water quality.

Many studies already have identified that pollutants accumulate on impervious surfaces, such as parking lots, roofs, driveways and roads.  Drainage from these surfaces is almost always “improved” by addition of storm inlets and storm sewers.  Unlike pervious surfaces, impervious surfaces begin to discharge stormwater in much smaller events, contributing to annual Runoff volume significantly as well as washing the accumulated pollutants into the water column in what we generally have called the “first flush”.  As we have been discussing, the impervious surfaces of the developed site are a “marker” for stormwater quantity and quality, and  in concept then, whatever is the “right” water quality control volume should be applied to the impervious area of a site.

Designing for water quantity in terms of flood damages, we typically target much larger storms.  Our small release rates tend to mimic the effect of measures which are explicit for “runoff volume control”, but do not capture and treat the first flush.

Discussing this issue at the Ordinance Update Steering Committee, we agreed that a re-focusing and change in emphasis was needed to better meet these dual quantity and quality challenges.  The current ordinance demands a high level of stormwater infrastructure to meet it already, and it is not really necessary to think of adding new costs to meet these goals.  Instead, we would redistribute the emphasis to fully acknowledge the “water quality control volume” as a high priority, with a corresponding de-emphasis on the total volume of detention storage required.

How much is “enough” for a water quality control volume?  Again, we can turn to some analysis of rainfall statistics that compare total rainfall in each storm to the total numver of “rainfall events” in a year.  We find the following:

• 70% of all rainfall events in a year have a total rainfall depth of 0.54 inches or less
• 85% of all rainfall events in a year have a total rainfall depth of 0.85 inches or less
• 90% of all rainfall events in a year have a total rainfall depth of 1.06 inches or less

In the above analysis, “events” are separated from each other by a minimum of 3-hours.  How would this be applied?  The above list thought of another way says, I need to design to capture and treat 1.06 inches of rainfall, applied over the impervious area of a site (assuming it is basically all runoff) if I wish to treat 90% of all the storms that occur.  We are ignoring the pervious areas in these “small events, which is a simplification but is balanced by the differences in impervious surfaces runoff characteristics when not all of the drainage from impervious surfaces is “improved”.

So if a site came in that was 10 acres in size and in its developed state it would be 50% impervious, and we wanted to capture 90% of all the events that occur in a year, a simplified approach would be to apply 1.06” rainfall depth to 50% of 10acres, for a total “water quality control volume” of 0.42 acre-feet that would need to be intercepted, held and treated by the use of BMP’s.  Corresponding to that calculated volume would be the simplified approach of “subtracting” that volume from any  calculated site runoff storage (detention) volume requirement that applies.

So here are some questions for feedback.

• Is this a good idea?
• What percentage of storms, or what rainfall depth, should be used to define the water quality volume?  85% of events-0.85” of rain? More? Less?
• How should it be applied?

Response to public comments so far…

We have received a number of comments in the “Public Comment” section of the website.  Before we start into the thick of the real drafting of the Ordinance Update, I want to respond and acknowledge the comments we have received, and to the extent I can let commenters know what is being done about the comment.  Rather than respond to each comment individually, we have “collapsed” similar comments into a single concern.

1. Comments on BMPs:  Volume credits should be provided for BMPs, permeable pavers should be encouraged, wetlands should be given credit for higher evapotranspiration and since they are more effective than dry ponds, guidance should be provided on soak away systems.  Response:  We are looking for all opportunities to properly credit the multiple benefits of BMPs as we proceed into Drafting Ordinance Update language.
2. Comments on Redevelopment:  Redevelopment exemptions are too difficult to achieve, they should be expanded and simplified. Redevelopment should be encouraged to avoid sprawl.  Response:  Requirements related to redevelopment are being re-thought, recognizing that redevelopment is something that current trends in water quality and stormwater management, as well as urban planning, would encourage.
3. Comments on Easements and Deed Restrictions:  The Ordinance should clearly state when and where BMP and SMA easements and deed restrictions are required for both public and private development sites, and, how they shall be recorded.  Response: Noted.
4. Comments on Restoration:  There should be a separate category for projects that are for restoration work.  Response:  We have come to recognize that restoration, along with a whole class of projects whose purpose is to improve the ecological health of the project site, should be treated differently.  Watch for work under the project category “Naturalization”, as the real purpose of that category is to respond to this comment.
5. Comments on CLOMR:  CLOMR requirement should be eliminated for BFE reductions when there is no floodway impact.  Response:  This will be considered in discussions on Floodplain/Floodway regulations.  The enabling legislation says we must be consistent with IDNR.
6. Comments on FEQ:  Consider alternatives to FEQ.  Response:  The required use of FEQ will be made clearer in the ordinance update.  As stated in the Watershed Plan, alternative models will be acceptable where appropriate.
7. Comments on restrictors:  Eliminate small diameter/small volume restrictors that are prone to failure and need constant maintenance.  Response:  While we will review this situation carefully, the ordinance has been in place a long time and several designs have come into common usage that do not seem to be the source of a lot of complaints.
8. Comments on Roadways:  Roadway procedures should be formalized.  Response:  We all agree, and we are looking closely at that.

As new comments are received, we will post additional responses.

This is a good point to recap where we are in the process, and respond to some comments we have received along the way.  There are several responses posted as follow-up comments over the last few days, so be sure and take a look.

We started this Update process by listening to what “users” of the Ordinance have to say about how it works now.  We reached out to a sample of 360 applicants and landowners that we had contact information for inviting participation.  The survey was also available to anyone who wished to take it here on this website.   We have summarized the responses and the comments received in a summary document, also posted in the documents section of the website.

We have held three “listening sessions” to date as well:  one with the Business community, one with DuPage Mayors and Managers Planning committee, and the third with the Forest Preserve District Board.  The comments received and summaries of each listening session are also posted here on the website.

As an earlier post indicates, we have looked at practices and trends in Stormwater Management nationally,  looking at what we can learn and anticipate from other programs and regulatory trends.  The results of that review are available here on the website.

The Steering Committee has also been active.  The minutes of the Steering committee meetings are here on the website as well.

We have started a general discussion on the current Ordinance identifying its structure, and deciding how best to structure and organize the updated ordinance to make it easier to use and clearer.   Our intent is that someone who contemplates “development” in the county will understand what they can do by right, what they can do only by permission, and what they cannot do, and that this determination can be made early in the process with a reasonable level of confidence.

We are now ready to move forward with drafting revised ordinance language.  Stay tuned to this site—we will start posting drafts as soon as the Steering Committee reaches consensus.

The National Ordinance Review Technical Memorandum has been finalized and posted to this site for several months. The Review helped to identify innovative practices and standards used by progressive stormwater programs across the Country, and included a number of recommendations for the update to DuPage’s Stormwater and Floodplain Ordinance. The key recommendations that may be considered for incorporation into the current update have been pulled into a separate document, with additional details and backup information that may be helpful.

We want to insure that the recommendations serve as input for the Steering Committee as it prepares to draft the ordinance update, and therefore we are posting this document (see attached) to this website so that each point can be discussed and refined.  We ask that Steering Committee members, designated municipal representatives, and the public provide comments on the recommendations pertaining to their feasibility for incorporation into the DuPage County Stormwater and Floodplain Ordinance. Your comments will be reviewed closely as decisions are made pertaining to each point.

Recommendations for Stormwater Ordinance Structure

The consultant team and the Steering committee are making progress in giving shape to an improved approach to permitting projects whose underlying purpose is to improve the ecological health of the County, whatever the economic driver of the project is.  An earlier blog post talked somewhat about this, and we are calling this category of project “naturalization Projects”.  A draft of both the guidance for this approach and specific ordinance language is coming soon for review, but we are anxious to get your feedback on this approach.

Recognizing that some projects improve rather than harm the environment may seem obvious, but language in an ordinance recognizing the fact presents a significant improvement on what is allowed under the current Ordinance while maintaining the level of protection the current Ordinance provides to wetlands and buffers. Below we have tried to summarize the positive benefits in the area of wetlands permitting we expect this Ordinance Update to produce:

1. One of the biggest complaints we hear is that the current Ordinance outright “Prohibits” impacts to wetlands and strongly discourages impacts to buffers unless it can be proven that there are no practicable alternatives.  The Ordinance, as written, assumes that avoidance of impact is the best alternative.  If wetland or buffer must be impacted the applicant must provide documentation to support that there are no practical alternatives to the impact.  Unfortunately, no specific listing of information is provided that details what that information should be, unlike other local Ordinances.

The updated version of the Ordinance will specifically define what is permissible, giving applicants and reviewer’s upfront knowledge regarding permissible projects. Applicants should be able to review their projects prior to making the formal submittal, determine what aspects of the project are not going to be allowed, make the necessary changes, and feel comfortable that provided they meet the requirements of the Ordinance that permit issuance is likely.

2. The Ordinance does not distinguish between temporary and permanent impacts. For example:

• • In the Ordinance’s current form, there is no ability to complete wetland enhancement or restoration without mitigating for the impacts caused by physically entering a wetland.  Under the current Ordinance, this is an impact to the wetland that must be mitigated.   The applicant has to create additional wetland or purchase credits for the impact.  This situation discourages restoration or enhancement of existing wetland areas because the applicant is penalized by having to mitigate the impact and increase the total area of wetland and associated buffer onsite.
  • The same situation would be true for installation of a utility line.  A utility line may be installed and grades returned to original contour.  Currently compensatory mitigation is required, however, the updated Ordinance will distinguish between temporary and permanent impacts, and in many circumstances, no additional compensatory wetland mitigation will be required, only restoration of the impacted area will be necessary.

Permitting for projects that involve only temporary wetland impacts should experience cost savings due to eliminated mitigation costs and improved turnaround times for reviews.

3. There are many situations in which the applicant is willing to install native vegetation or enhance existing plant communities within their project site; however there is no direct benefit to the applicant in the permitting process for doing so. The updated Ordinance will give wetland mitigation and BMP credit to the applicant for installing native vegetation within the development, provided it meets a minimum floristic quality standards established in the permit review process.

EPA is announcing plans to initiate national rulemaking to establish a program to reduce stormwater discharges from new development and redevelopment and make other regulatory improvements to strengthen its stormwater program.

EPA has issued a Federal Register Notice (PDF) seeking stakeholder input to help EPA shape a program to reduce stormwater impacts. Input will be provided through both written comments and during a series of public listening sessions. As described in the FR Notice, EPA seeks input on the following preliminary regulatory considerations:

• Expand the area subject to federal stormwater regulations
• Establish specific requirements to control stormwater discharges from new development and redevelopment
• Develop a single set of consistent stormwater requirements for all MS4s
• Require MS4s to address stormwater discharges in areas of existing development through retrofitting the sewer system or drainage area with improved stormwater control measures
• Explore specific stormwater provisions to protect sensitive areas

Please see the website below for more information.

http://cfpub.epa.gov/npdes/stormwater/rulemaking.cfm

The Steering Committee has settled on a “structure” for the Ordinance update.  The Stormwater Ordinance will be reformatted to create a series of “upfront” sections that will steer an applicant directly to the applicable regulatory section for the specific development, and specific site characteristics under consideration.  This will be partly in the form of a matrix and partly in the form of text under appropriate front-end articles.

An applicant would first characterize the site he intends to build the project on.  The steering committee approved the following categories that pertain to the site pre-project.

1. The degree to which a site is already “developed”, as indicated by the “Total Impervious Area” (TIA) of the site.  Degrees of development threshold distinctions are contemplated at the less than 15% TIA, 15% to 50% TIA, and greater than 50% TIA.
2. Whether or not a site includes “Waters of DuPage County”.
3. Whether of not a site includes a “Regulatory floodplain”.

Note that a site may be included under more than one category.

Next, the applicant must characterize the proposed project.  The Steering Committee has given a conditional nod to the following project characterizations as a starting point to be used in determining which Ordinance requirements apply.

1. Those not meeting the requirements of the categories below will be classified by one or more of the following:
   1. Change in Impervious area
   2. Grade changes
   3. Modification of existing structures
   4. Construction of new structures
   5. Modifications of existing buildings
   6. Construction of new buildings
   7. Linear Transportation Project-Vehicle and pedestrian facilities in linear land holdings created for that purpose.
   8. Naturalization Project-A project, or a portion of a larger project, whose purpose is
      1. Streambank Stabilization
      2. Wetland Mitigation
      3. Wetland Mitigation Bank
      4. Water Quality Improvement
      5. Stream, Stream habitat, and Upland habitat Restoration; and Forestry management activities
      6. Watershed Plan Implementation Projects

Based on the characteristics of the site, and the characteristics of the project, the applicant will be directed to specific articles that will define limitations, methodologies, standards and mitigation requirements where appropriate.  It is anticipated at that all developments will have certain requirements they must meet, some of them procedural and some regulatory.  Procedural requirements that might apply to all include such things as the form and content of a permit submittal, development security, Maintenance requirements, violations, appeals, variances and the like.   Universal Regulatory requirements might include such topics as erosion and sediment control and incorporation of Best Management Practices.  Within those topics, specific requirements can be tailored to the site and project classifications as appropriate, instead of a one-size-fits-all approach.

This concept is a starting point in the Update, and of course will be more fully developed as we proceed.  What do you think?  What problems do your foresee with this approach as applied to your own community?

The Consultant team has been talking to Staff at DuPage County who regularly review Special Management Areas about the idea of creating a special project “category” for projects whose purpose is primarily to improve, restore or protect “natural features” of the landscape.  We will be bringing a fuller discussion of the issues to the Steering committee very soon.   Natural features of regulatory significance in the current ordinance include “Waters of DuPage”, and Riparian areas.  These categories refer to what is on the site pre-project, and do not speak directly to the nature of the project itself.  Not all projects represent degradation of the existing resource, and in many cases the environmental resource is not “better off in a no-build scenario”, compared to its expected condition after a project is built.  Examples of the types of projects we are referring to here include:

• Wetland creation
• Wetland and Steam Restoration
• Streambank Stabilization
• Retrofitting of BMPs to existing development
• In-steam aquatic habitat creation or enhancement projects
• Enhancement of existing degraded wetlands and riparian areas.

There are good reasons why a stormwater ordinance needs to look at these types of projects differently, and it seems advisable to create a vehicle within the ordinance structure to do so.  To date, we have named this category “naturalization projects”.  The need for development mitigation factors like “site runoff storage (detention)” and some other mitigation practices would be applied differently or sometimes not at all to naturalization projects, as the “development” involved in such projects is a form of mitigation for old developments.

Do you see these categories as in need of different requirements from a stormwater perspective?  What other types of projects should such a category encompass?  What sections of the Ordinance, if any, would be applied differently in your view?

The Federal Environmental Protection Agency (EPA) has now developed their Final Rules for limiting pollution from construction site runoff.  In discussions with the Illinois Environmental Protection Agency (IEPA), the State has indicated unofficially that they were waiting for the EPA’s final rules before tackling this issue in Illinois.   The federal rules will be phased in, according to the fact sheet.  More information on this federal regulation can be found at the following link:

http://www.epa.gov/waterscience/guide/construction/

How do you think this should influence this ordinance update effort?  Should we try to anticipate the Federal/State rules, or leave that issue for a future update when the State has had a chance to implement this rule making in Illinois?