Once again, the Western Dane County Coalition for Smart Growth and Environment has an excellent analysis of how yet another new sprawl development will harm our water resources.
4-5-10
To: Capital Area Regional Planning Commission (CARPC) Members
From: Western Dane Coalition for Smart Growth and Environment (WDC/SGE)
Re: City of Verona Urban Service Area (USA) amendment request
The CARPC staff report on the City of Verona USA amendment request issued on June 11, 2009 concludes with eleven specific recommendations to be imposed on Verona as conditions for the requested approval. These recommendations were put in place in order to minimize water quality impacts of the proposed development on the extremely sensitive exceptional Upper Sugar River and Group 1 wetlands located in the State Natural Area, coldwater Badger Mill Creek and other minor wetlands present in the area. Because the City of Verona deemed some of the CARPC staff recommendations as “unreasonable restrictions”, the decision on the request was postponed and the case was sent to the Environmental Resources Technical Advisory Committee (ERTAC or TAC) to be resolved.
The newly-emerged set of recommendations (CARPC staff report 4-8-10), resultant from TAC’s involvement, represent a weakened version of what was originally offered by the CARPC staff in June 2009. These new recommendations if approved, undoubtedly will have an additional negative water quality impact on the affected resources.
Here is a description of how the two sets of recommendations differ and what is missing in recommendations.
Control of runoff volumes and peak rates
Although both versions of recommendations offer control of peak rates of runoff to pre-settlement levels in all storms, they largely differ in volume control standard. While the old version insists on maintaining the pre-development runoff volumes, which is the same as 100% volume control to pre-development levels, the new version calls for the post-development volume control of only 90%. This particular difference in runoff volume control is significant.
According to the CARPC staff report of 6-11-09 (p 37), even if peak runoff rates from sites are controlled, increases in runoff volume from a site can lead to increases in flood peaks at downstream locations. Increased runoff volumes lead to other unwanted consequences, such as stream bank erosion, stream bank destabilization, sedimentation, increased water temperatures and degradation of biotic communities. The report goes on to say that even relatively small amounts of urban land use in a watershed can lead to major changes in biotic communities and that there is a relatively low threshold point for these changes to take root, beyond which there is no recovery of lost water quality (p 40).
A 10% difference in volume control standard between the two sets of recommendations might appear as unimportant at the first glance. Nevertheless it is significant. The event based modeling for Shady Woods Residential Development (CARPC 12-15-09) demonstrates that 90% volume control standard will lead to runoff volume increase anywhere, between 38% to 156%, depending on the type of vegetation and soil conditions present at the pre-development level. At any rate, the CARPC staff report of 6-11-09 (p 48), expresses the opinion that all new development in Badger Mill Creek and Sugar River sub-watersheds should uphold no increase in runoff volume standard. It calls it “the only practicable approach that would prevent further degradation of these sensitive cold fisheries.”
And the following statement is what the same CARPC staff report (p 41) had to say in reference to Verona’s proposal to recommend for 90% runoff volume control to predevelopment level, 100% peak runoff rate control to pre-settlement level and 80% reduction of suspended sediments – all three measures now a part of the current proposed recommendations:
“Although these measures and standards are above current minimum standards, and will reduce the likely impact of the proposed development, they do not completely address the current state of the receiving waters. To address the potential adverse impact of increased runoff volumes in the Badger Mill Creek and the Sugar River downstream of the confluence, it is important to maintain post-development runoff volumes equal to predevelopment volumes up to the 100-year storm event for all new development (100% pre-development stay-on volume). This will promote the goal of maintaining existing hydrology, which is critically important to maintaining the health of Badger Mill Creek, Sugar River, and the biological communities that they support.”
TAC recognized the benefits of runoff volume control to 100% of pre-development volumes. However, it has decided that concerns over additional costs are more important than the full water quality benefit such measure would produce. But this is an unacceptable argument when proposed by a committee serving a regional planning commission responsible for protecting the environmental quality of the county’s land and water resources.
Caps on the extent of the infiltration areas
The original CARPC staff recommendations ask for maintaining the pre-development recharge rates with no caps on the extent of infiltration areas. The 4-8-10 CARPC Executive Summary (p 4) continues to support this position in the body of the text:
“Allowing a cap has the potential for reducing the volume control and recharge required to well below the recommended standard and could result in inconsistency in the effectiveness of the standard between amendments.”
It views pre-development recharge rate caps as “a large loophole, where the developer is allowed to maximize the development beyond the carrying capacity of the site and insists on limited mitigation because of their development choices.” (pp 4 & 5).
However, the specific new recommendations omit all reference to the “no-cap” rule. Therefore in spite of what is stated elsewhere in the document, the lack of reference to “no cap” rule in recommendations reserves the option for the City of Verona to use the much weaker Dane County ordinance, which allows such caps on 1% or 2% of the total site area to be used for infiltration, dependant on type of proposed development.
Limitation of the size of the infiltration area affects the amount of water that gets infiltrated and eventually recharged to groundwater. It is especially important in this case because of the sensitivity of the water resources involved, and because of very difficult soil and terrain conditions which do not lend themselves to easy infiltration.
Water temperature control
Both the original and new sets of recommendations require thermal impact mitigation. Nowhere in any CARPC reports is there any mention of how this goal would be met. Both Badger Mill Creek and the Sugar River are classified as coldwater communities. In an earlier CARPC case involving a proposed USA amendment affecting Black Earth Creek, lack of demonstrable assurance that coldwater temperatures in that creek would be protected against the proposed development, played a role in CARPC denying that application. By contrast, in the case of the City of Verona, a proposed development affecting two coldwater creeks, one of them exceptional water resources, absence of any concern about how thermal impact mitigation would be met noticeably stands out.
An excellent recommendation, of total runoff peak control rate to pre-settlement levels in all storms, should be followed by an explanation of how it is expected to work in conjunction with thermal mitigation. The standard in peak flow rate control is extended detention for 1-year, 24-hour storm to be gradually released over 12 hours in cold watersheds (CARPC staff report 6-11-09, p 42), and over 24 hours in warm watersheds. But what will happen with larger volumes of water in larger water storms? Is the runoff allowed to warm up during longer retention, in order to control peak flow? Or will it be released quicker in larger volumes in order to avoid warming? These are the types of questions that any reasonably coherent, although not necessarily complete stormwater management plan should have been able to provide the answers for.
What is the enforceability in Wisconsin of Minnesota Board of Water and Soil Resources 2006 criteria?
One of the more curious new recommendations is that the criteria for maintenance of wetland water levels provided by the Minnesota Board of Water and Soil Resources 2006 be used by Verona. Although these criteria might be the best ones in existence, it is highly questionable how either CARPC or DNR would ever be able to legally compel a Wisconsin municipality that it failed to follow Minnesota’s regulations, if the need to sue over water quality should ever rise.
Delineation of environmental corridors
Both recommendation sets call for delineation of environmental corridors based on wetland, stream and floodplain delineations, as well as on CARPC requirements. However, the new recommendations have dropped all reference to a 300 ft vegetative buffer for the commercial area east of STH 69. This buffer, described in the original staff recommendations, is needed to protect the lower portion of Badger Mill Creek and associated wetlands. Similarly, a recommendation that the western portion of Area W be designated as environmental corridor in order to protect the shallow groundwater in that area was also eliminated. These sacrifices of water quality protection obviously were done for the convenience and monetary benefit of the would-be developers of these areas and their municipal partner.
Area W
Most part of Area W is unsuitable for infiltration because it contains sub-areas where such infiltration is inhibited either by fine-grained soils or by shallow, fractured limestone or by high water table. The original staff report suggested several alternative approaches to address this problem. CARPC Executive Summary of April 8, 2010 reports that the resolution of the infiltration problems in this area would not be a part of the conditions for the approval of this amendment. According to the summary (p 4),
“The City prefers to maintain its flexibility”.
But flexibility in environmental protection almost always generates environmental degeneration.
Will the recommended water quality standards deliver the intended performance?
The CARPC Executive summary quotes a DNR letter which states, that without performance measurement of infiltration practices there can be no assurances that the infiltration practices are working as intended and that water quality is protected (p 3).
In the City of Verona’s USA amendment request, performance measurements of infiltration practices are not the only unknown variable. The amendment area is a large mosaic that comprises challenging terrains and difficult infiltration conditions that include steep slopes, shallow and in many places fractured bedrock, high water tables and deep fine grain sands. Nothing even approaching a stormwater management plan has been submitted to CARPC for review, let alone submitted to “performance measurement”. And yet CARPC staff, in spite of its earlier more cautious approach expressed in the 6-11-09 report now seems to be all too ready to gamble with water quality of not just one coldwater stream, but of two, one of which happens to be an “exceptional water resource”. What will happen if Verona’s request gets the needed approval now and its still unknown eventual stormwater management plan gets implemented and fails to work as promised? Who will ever undo the damage to the Upper Sugar River, Badger Mill Creek, the wetlands, the State Natural Area?
The City of Verona and Stormwater Management
Many of Verona’s best management practices (BMPs) date to the1980’s when water quality mitigation standards were lower. Now those facilities need retrofitting to improve their performance. Any such work on BMPs requires large sums of money, which are not easily allocated for these purposes.
As of 6-1-09, the City of Verona had 61 detention basins, two infiltration basins and one bioinfiltration basin. 47 of these facilities are public, 15 private and three are of unknown ownership. The City inspects them on irregular basis and repairs them as need arises, usually after reported flooding.
As of December 2008, Verona was under watch for total suspended soils (TSS), the only pollutant under formal reduction regulations by DNR. In order to reach its goal of 40% TSS reduction the City needed to reduce its base load by 139 tons per year. At that time the City was reducing TSS by 83 tons or 24%. The estimate for 40% TSS reduction was $2.7 million.
All municipalities, including the City of Verona are mostly concerned with expanding their tax bases. Regardless of their public propaganda to the contrary, water quality is never their primary focus. It is unwise of the CARPC to ignore their own responsibility as a watchdog agency for water quality, and turn over these watchdog responsibilities to a municipality and its private developers, letting them dictate terms and conditions under which the CARPC’s recommendation of the amendment approval would be issued to DNR.
It is equally unwise to contemplate recommending anything for approval before a detailed stormwater management plan has been produced and shared with the public. When it comes to water quality protection, no municipality should ever be allowed to do its “own thing” in an environmental area that is difficult to mitigate, with high potential to harm sensitive water resources, such as suggested that the City of Verona should be allowed to do in Area W.
Backed by NR 121.05 (1) (g) 2. c., which based on considerations of water quality, allows for exclusion from a USA of steep slope, highly erosion-prone soils, limiting soil types, recharge areas and other physical constraints, the proposed amendment area should be rejected. As long as such is done for solid water quality reasons, expressed in open deliberations, DNR will have the means of proving that it backs a CARPC decision.
Stefi Harris and Arnold Harris
WDC/SGE
3427 County Rd P
Mt Horeb WI 53572