Innovations in Wetland Regulation
Subwatershed- and Function-Based Regulation
Integrating Wetland and Stormwater Regulation
by Chuck Holtman July 8, 2008
This article reviews the increasing importance of understanding a wetland’s role within the hydrologic and ecologic systems of which it is a part. The ongoing development of tools for assessing the types and levels of functions the wetland plays in this context allows for continuing movement away from acre-based wetland impact mitigation and offers landowners and developers opportunities for more efficient land use. Minnesota and federal wetland management laws for some time have required that proposed wetland impact and mitigation be evaluated in a system context, but this requirement is expected to be much more prominent in the future.
Several features of wetland and surface water regulation are driving this shift away from parcel-focused assessment of wetland impacts and acre-based replacement obligations. These include:
- the recently adopted federal mitigation rules, which include much more explicit text about watershed-level evaluation and raise the prospect of lower mitigation acreage ratios when a property owner demonstrates that proposed mitigation will preserve wetland function;
- the authority under the Minnesota Wetland Conservation Act (WCA) for a local implementing agency to adopt a “comprehensive wetland protection and management plan” that can advantage property owners who demonstrate preservation of wetland function;
- increasing incorporation of wetland resources into stormwater management plans and the ability to achieve stormwater management credit for doing so; and
- incorporation of wetland management activities into Total Maximum Daily Load implementation plans, with responsibility either placed directly on property owners or, more likely, placed on local land use authorities to be carried out through development ordinances.
- Wetland “Function and Public Value”
- Minnesota Wetland Conservation Act
Put most simply, the WCA requires two things: (1) wetland impact must first be justified; and (2) wetland resources must be replaced to compensate for the impact.
The WCA rules, Part 8420, understand compensation to refer to replacement of the ecological functions and “public value” wetlands provide. This is stated repeatedly. E.g., Minn. Rules 8420.0105; 8420.0520, subp. 1; 8420.0546; 8420.0547, subp. 2; 8420.0549, subp. 1; 8420.0550, subp. 1; 8420.0600.
Wetland “public value” is defined as “the public benefit and use of wetlands as determined based upon an assessment of the wetland functions listed in part 8420.0103.” That rule lists as wetland functions:
- water quality, including filtering of pollutants to surface and groundwater, utilization of nutrients that would otherwise pollute public waters, trapping of sediments, shoreline protection, and utilization of the wetland as a recharge area for groundwater;
- flood water and storm water retention, including the potential for flooding in the watershed, the value of property subject to flooding, and the reduction in potential flooding by the wetland;
- public recreation and education, including hunting and fishing areas, wildlife viewing areas, and nature areas;
- commercial uses, including wild rice and cranberry growing and harvesting and aquaculture;
- fish, wildlife, and native plant habitats;
- low-flow augmentation; and
- other functions, values, and public uses as identified in board-approved wetland evaluation methods.
Despite the numerous affirmations of the function-based replacement standard, in practice WCA replacement obligations have tended to be acreage based. There are at least three reasons for this:
- Acres are easy to measure. Acre-based replacement is simpler and less expensive to administer.
- Function-based replacement requires a method of assessing functional losses and gains that is reasonably quantitative, reliable and reasonable to apply. Development of such methods has taken time and still faces scientific and technical challenges.
- To avoid sole reliance on an uncertain functional replacement standard, the WCA also specifies minimum acreage replacement ratios: generally two replacement acres for each acre of impact, with a one-to-one acre replacement minimum on agricultural land and in those parts of the state retaining at least 80 percent of pre-settlement wetland acreage. The WCA rules elaborate this rather simple statutory standard with an acre replacement framework in which the minimum ratio of replacement to impact acres depends on the location, type and timing of the replacement wetland. Minn. Rules 8420.0546, 8420.0549. The more developed this framework, the greater the tendency simply to apply the acreage ratios and deemphasize the more difficult comparative functional analysis.
Nevertheless, there are some parts of the WCA where an assessment of wetland function – diminished function due to wetland impact or function added by replacement – assumes a more prominent role:
- For a temporary impact to qualify as “no loss,” and therefore not require replacement, wetland function and value must be restored within six months of impact. Minn. Rules 8420.0520, subp. 5.
- To qualify for “sequencing flexibility,” i.e., justify wetland impact in certain situations without demonstrating avoidance, minimization, rectification or elimination, a property owner must demonstrate that wetland function and value will be maintained as between pre- and post-impact scenarios. Minn. Rules 8420.0520, subp. 7a.
- Replacement credit for restoring the hydrology and/or vegetation diversity of a wetland with “exceptional natural resource value” (see Appendix) may be based entirely on an assessment of functional enhancement without an acreage minimum. Minn. Rules 8420.0541, subp. 4.
- In applying the minimum acreage replacement ratios of the WCA rules, a higher minimum ratio (typically adding a factor of 0.25 to the replacement acreage) is required for replacement of wetland of a plant community type different from that of the affected wetland. Minn. Rules 8420.0549, subparts 3 and 4c. (This rule, in part, assumes that replacement with the same plant community type is more likely to replace the functional palette of the affected wetland.)
- When the jurisdictional impact is in the form of partial wetland drainage, the LGU may set replacement as either (a) an acreage ratio as low as 50% of the partly drained acres; or (b) replacement determined entirely on the basis of a functional assessment, without a minimum acreage requirement. Minn. Rules 8420.0549, subp. 5. A wetland cell within a stormwater treatment system may receive full replacement credit, on an acreage basis, if (in addition to meeting other criteria) its function as a wetland is sustained. Minn. Rules 8420.0541, subp. 10.
- Functional Replacement Under Clean Water Act Section 404
The relation of acre-based impact mitigation and wetland functional assessment in Section 404 permitting is stated in new mitigation rules adopted recently by the U.S. Army Corps of Engineers (USACE) and the Environmental Protection Agency (EPA), 73 Fed. Reg. 19154 (April 10, 2008) (see Appendix for excerpt). These rules supersede USACE Regulatory Guidance Letter (RGL) 02-02. The emphasis of the new rules is to further shift mitigation preference toward established wetland mitigation banks, but the rule also formalize the endorsement of watershed-based and function-based mitigation. The rule comments announce:
With this rule, we are encouraging the use of functional and condition assessments to determine the appropriate amount of compensatory mitigation needed to offset authorized impacts, instead of relying primarily on surrogate measures such as acres and linear feet. In the future, there will be more assessment methods available to quantify impacts and compensatory mitigation.
73 Fed. Reg. 19633. The new rules state that the USACE district engineer “must use a watershed approach to establish compensatory mitigation requirements ... to the extent appropriate and practicable.” 33 CFR 332.3(c)(1). This approach:
considers the importance of landscape position and resource type of compensatory mitigation projects for the sustainability of aquatic resource functions within the watershed. [It] considers how the types and locations of compensatory mitigation projects will provide the desired aquatic resource functions, and will continue to function over time in a changing landscape. It also considers the habitat requirements of important species, habitat loss or conversion trends, sources of watershed impairment, and current development trends, as well as the requirements of other regulatory and non-regulatory programs that affect the watershed, such as storm water management or habitat conservation programs. It includes the protection and maintenance of terrestrial resources, such as non-wetland riparian areas and uplands, when those resources contribute to or improve the overall ecological functioning of aquatic resources in the watershed.
33 CFR 332.3(c)(2). The amount of compensatory mitigation is that which is “to the extent practicable, sufficient to replace lost aquatic resource functions.” 33 CFR 332.3(f)(1).
Similar to the WCA rules, the federal rules aspire to mitigation based on functional assessment but recognize that an acreage standard is needed so long as further efforts are needed to develop and refine functional assessment methods:
In cases where appropriate functional or condition assessment methods or other suitable metrics are available, these methods should be used where practicable to determine how much compensatory mitigation is required. If a functional or condition assessment or other suitable metric is not used, a minimum one-to-one acreage ... compensation ratio must be used.
33 CFR 332.3(f)(1). The rule comments, however, suggest that a ratio of less than one-to-one can be used “where a functional or condition assessment or other suitable metric is used.” It notes, however, that even in these cases a higher ratio typically will be justified to account for factors such as the uncertainty of full functional replacement and temporal losses. 73 Fed. Reg. 19633.
Finally, the rules direct the district engineer to rely on a local watershed plan for watershed-based mitigation decisions when such a plan is available. 33 CFR 332.3(c)(1).
- Joint Wetland Mitigation Guidelines
On May 20, 2007, the Minnesota Board of Water and Soil Resources (BWSR) and the U.S. Army Corps of Engineers (USACE) signed an interagency memorandum of understanding (MOU) titled “Wetland Mitigation Guidelines” (see Appendix). The MOU is intended to further consistency between wetland impact mitigation decisions under WCA and Section 404 permitting.
With respect to watershed- and function-based mitigation, the primary thrust of the MOU would be to rest mitigation credit amounts more directly on the outcomes of functional assessment rather than on largely nominal and approximate percentages of acres. Credit for the following would be based entirely or largely on functional assessment: hydrologic restoration of partly drained wetland; vegetative restoration of cropped wetland; vegetative restoration of degraded wetland; wetland preservation; and creation of wetland cells as a part of water quality treatment practices.
For these changes to become effective at the state level, they must be incorporated into the WCA rules through formal rulemaking. The broad rulemaking effort currently underway is providing a framework for these changes to be considered. At the federal level, the use of functional assessment in mitigation decisions is less specific in rules and more a matter of the discretion of the USACE district office. Accordingly, the USACE St. Paul District engineer is in a position to integrate the MOU guidelines into permitting practice.
- Minnesota Wetland Conservation Act Put most simply, the WCA requires two things: (1) wetland impact must first be justified; and (2) wetland resources must be replaced to compensate for the impact. The WCA rules, Part 8420, understand compensation to refer to replacement of the ecological functions and “public value” wetlands provide. This is stated repeatedly. E.g., Minn. Rules 8420.0105; 8420.0520, subp. 1; 8420.0546; 8420.0547, subp. 2; 8420.0549, subp. 1; 8420.0550, subp. 1; 8420.0600. Wetland “public value” is defined as “the public benefit and use of wetlands as determined based upon an assessment of the wetland functions listed in part 8420.0103.” That rule lists as wetland functions:
- Comprehensive Wetland Protection and Management Plan
The WCA, however, allows the most comprehensive deviation from the acre-based replacement framework under the provision for comprehensive wetland protection and management plans (CWPMPs). Minn. Rules 8410.0650 (see Appendix). The basic principles of a CWPMP are as follows:
- The WCA implementing body (local government unit, or LGU) inventories wetlands. It classifies wetlands on the basis of wetland function and public value (Minn. Stat. §103B.3355). It uses the classification to regulate wetland impacts and determine replacement requirements.
- On the basis of the wetland classification system, the LGU may specify an approach to justifying impacts that does not follow the compulsory WCA sequencing hierarchy of avoidance, minimization, rectification, elimination and replacement (Minn. Rules 8420.0520).
- The LGU may specify a wetland replacement acreage ratio more stringent than the WCA minimum on the basis of its wetland classification scheme, and may redefine which wetland-enhancing actions qualify for replacement credit. For areas where between 50 and 80% of presettlement wetlands remain (Anoka, Becker, Benton, Chisago, Morrison, Otter Tail, Sherburne and Todd Counties), the minimum replacement ratio is acre for acre, rather than the 2:1 ratio that otherwise would apply.
- A CWPMP must show that there will be no net loss of wetland quantity, quality, or biological diversity over the period of CWPMP implementation. This period must be 10 years or less.
- The LGU must adopt an ordinance or rule to implement the CWPMP. The CWPMP process begins with LGU notice to BWSR, the Department of Natural Resources (DNR), the Pollution Control Agency (PCA), the affected municipalities and the public. The WCA Technical Evaluation Panel (representatives from BWSR, the county conservation district and the LGU, with DNR and USACE participation) must be consulted throughout plan development.
BWSR must approve the CWPMP. It may disapprove only if the plan does not meet the terms of Minnesota Rules 8420.0650. If a municipality or BWSR disagrees with the plan, there is a process of communication to address alleged deficiencies, a hearing before the Dispute Resolution Committee of the BWSR Board, an opportunity for mediation, and ultimately District Court review focused solely on whether the plan conforms to section 8420.0650.
- Rice Creek Watershed District: Experience with the CWPMP and the U.S. Army Corps of Engineers
The RCWD encompasses all or part of 30 cities and townships in the northern Twin Cities metro counties of Ramsey, Anoka and Washington. The terrain is largely flat, and much of the area lies within the Anoka sand plan. Urban development in the upper half of the watershed presses against traditional agricultural use. Rising conservation values are in tension with an extensive array of public drainage systems on which landowners rely for row cropping, peat farming, pasturing and other land-based activity. Cities are planning for development and considering how to transition surface drainage systems to urban stormwater management purposes. Over the past several years, the RCWD, in conjunction with local land use comprehensive planning, has developed four CWPMPs to manage these competing concerns within four areas anticipating development.
- Village Meadows
The Village Meadows CWPMP, approved in 2004, encompasses about two square miles in the City of Blaine constituting the principal drainage area of Anoka County Judicial Ditch 53-62. Before settlement, this flat area consisted of wet prairie types interspersed with oak savanna. It was ditched at the turn of the previous century to enhance settlement and cultivation. The marginal nature of the area for cultivation is reflected in the fact that initially, the ditch ran to the north and east, and some 15 years later, it was reversed to drain to the south. Strong development pressure instigated the CWPMP effort (among other things, this was the erstwhile site for the Vikings stadium).
The RCWD engineer concluded that due to high groundwater, flat terrain and peaty soils, a repair of the ditch to its originally constructed profile would result in narrow corridors of drained land surrounded by wetlands. This would yield some benefit for cultivation, but much less for land development, particularly given floodplain and other setbacks in the local code.
A ditch cleanout (Minn. Stat. §103E.705) would have drained some 200 acres of wetland exempt from replacement under Minnesota Rules 8420.0122, subpart 2(C); drainage of some 70 acres of Type 3 and 4 wetlands would not be exempt, and would need to be replaced. Remaining wetland would be fragmented and vulnerable to adjacent development, and therefore of compromised resource value. Nevertheless, the cleanout to some extent looked to become a legal obligation because, due to rapidly rising land prices, the criterion of cost-effectiveness that largely defines the repair obligation of the drainage authority (RCWD) likely would have been met.
For some years, substantial ditch maintenance activity was deferred in light of the absence of good options, but this left many landowners unsatisfied. In other words, pressure was building for an action that was not going to make anyone particularly happy. The RCWD engineer thus was given a two-square-mile canvas to engineer the restoration and enhancement of a wetland landscape long ago debilitated by ditching and vegetative manipulation.
The goal was to reinstate a large, contiguous high-functioning wetland complex providing equivalent or better drainage and flood-prevention capacity to property owners. This outcome would be created, piece by piece, by the developing property owners, at very little public cost. Because it was to be “engineered” on an area basis, the CWPMP could use the sequencing flexibility of the WCA text to eliminate the need for the otherwise obligatory avoidance and minimization analysis. At the same time as wetland restoration and protection was directed at the center of the site, development would aim at the edges. As a tradeoff, fragmented, less highly functioning and more vulnerable wetland would be permitted to be filled to aggregate upland for development adjacent to public infrastructure.
Developing the CWPMP involved four key technical elements:
- Inventory and delineation of existing wetlands and a “lateral effect” analysis. The lateral effect analysis uses soils, precipitation and groundwater data to model the impact on wetland hydrology and extent of effective drainage under different ditch cleanout scenarios.
- Wetland function and public value assessments under the existing condition, ditch cleanout and implemented-CWPMP scenarios.
- Modeling of the hydrologic system and the hydraulics within the ditch channel (XP-SWMM) under the existing condition, ditch cleanout and implemented-CWPMP scenarios to delineate the floodplain footprint of each scenario for development purposes.
- Developing criteria for wetland impact sequencing and replacement to ensure a net gain in the quantity, quality and biological diversity of the wetland resource as the CWPMP is implemented.
The CWPMP implementing rule has several key elements:
- A minimum acreage replacement ratio of 1:1 (in accordance with Minn. Rules 8420.0650 for a 50-80% county).
- Replacement criteria locating allowable impacts and required replacement to:
- direct development to the plan area periphery, with allowed filling of lesser-valued wetlands; and
- preserve high quality wetlands and interspersed uplands; situate restored or created wetland to form a part of a 400- to 500-acre, hydrologically connected wetland/upland complex; and largely ensure a net gain in wetland function and value associated with the development of each parcel.
- The precise replacement requirement determined on the basis of a delineation performed by the applicant at the time of development.
- Replacement obligation may not be met with banked credits generated outside of the CWPMP area (though banked credits may be created within the area for use elsewhere).
- A permanent 50-foot undisturbed vegetated buffer around the wetland, memorialized on the deed.
- Protective standards for post-construction stormwater management.
- Dedication to the RCWD of an easement over the wetland and buffer areas allowing the RCWD to manage wetland hydrology and vegetation if it chooses (the easement does not create public access).
The RCWD did not establish wetland replacement acreage ratios above the 1:1 minimum specified in the WCA, for two reasons. First, the careful design based on extensive field work increased the reliability of wetland creation and restoration and the certainty of functional gains. Second, in the implicit bargaining, the RCWD chose instead to request from affected landowners what adds to the reliability of functional gains from replacement -- rigorous stormwater management requirements, vegetated buffer, and a hydrologic and vegetative easement.
- Army Corps of Engineers and Clean Water Act Section 404
The Army Corps (USACE) has no legal authority over the terms of a CWPMP. But much of the value of a CWPMP for a landowner or developer is the relative certainty it provides as to the locations of permitted wetland impacts and the timeframe of wetland permitting. To avoid undermining this landowner value (which in turn allows for better ecological outcomes under the implicit quid pro quo of the CWPMP), it is desirable to establish concurrently that Section 404 review will come out in about the same place as the CWPMP implementing rule. However, ultimately the USACE found itself legally constrained and otherwise unwilling to make important commitments at a plan level and in advance of specific development proposals.
USACE authority allows it to issue an area-wide permit in combination with an expedited review process for individual proposals. The vehicle is the Special Area Management Plan (SAMP), a type of programmatic permit authorized in Regulatory Guidance Letter (RGL) 05-09 (see Appendix). Apart from RGL 05-09, one can find statements in a number of USACE rule and guidance materials – before and including the new mitigation rules -- endorsing the concept of subwatershed- and function-based permitting under Section 404.
However, the St. Paul District considers certain legal requirements to constrain its ability to implement area-based permitting. It has approved only one SAMP to date, sponsored by the City of Superior, Wisconsin. This SAMP involved a limited number of parcels within a fairly small redevelopment area and included a very concrete evaluation of development alternatives. In other words, it was essentially a number of individual permit reviews conducted in parallel and packaged together. In addition, all mitigation was to be performed and guaranteed by the City of Superior. These are the obstacles that limit the District’s ability to do area-based permitting:
- Foremost is the avoidance and minimization analysis required to demonstrate the need to fill wetland. The position of the St. Paul District is that this analysis – principally the exploration of off-site and on-site alternatives -- can be done only once a project purpose and the economic and physical parameters of a specific development proposal have been identified.
- Second, under CWPMP authority the RCWD was able to count, as drained wetland, wetland that would be drained by a legal ditch repair and exempt from WCA replacement, without actually performing the repair. Although wetland drainage is outside of Section 404 jurisdiction, the position of the St. Paul District was that it could not consider the wetland as drained unless the cleanout actually had occurred. In part, this was due to the District’s position that the lateral effect modeling in the CWPMP overstated the extent of drainage from cleanout.
- Third, the St. Paul District is concerned to have a high level of assurance that mitigation will be successful (in part due to recent publicity about mitigation failure and poor USACE post-mitigation oversight). This concern is heightened in the CWPMP context, where the implementation time frame is expanded and the scope is larger. (This concern also is fed by the USACE’s legal position that the Miscellaneous Receipts Statute, 31 U.S.C. 3302(b), deprives it of authority to hold permittee sureties.) In the Superior SAMP, the City of Superior took responsibility for all of the wetland replacement; conversely, all of the Village Meadows replacement is on-site, and the landowner’s responsibility. The District very much wanted the RCWD to guarantee all of the private party mitigation. The RCWD resisted this. (If a different local unit of government is more willing to assume this responsibility, it probably has special assessment, development fee and surety tools it can use to recover costs from benefited landowners and otherwise protect the public pocketbook.)
- Finally, the SAMP process, and plan-based permitting in general, requires the dedication of USACE technical resources that the District’s regulatory section is not well staffed or organized to provide. Ultimately, the District was willing to import these resources from other USACE offices to assist in working through issues with the RCWD. However, a meaningful programmatic shift toward this approach would require these resource limits to be addressed in a more fundamental way.
Some months of effort to resolve these issues were partly fruitful. The RCWD and the St. Paul District settled for a memorandum of understanding in which the District formalized its concurrence in the technical bases of the CWPMP (scope and effect methodology and analyses; methodology and outcome of the wetland functional assessment; and criteria used to determine the location and type of wetland replacement required). The St. Paul District retains its independent discretion, as it performs Section 404 review on development proposals, to determine the permissibility of impact, the extent of impact and the amount, nature or location of required mitigation. However, the MOU improves the likelihood that it will reach conclusions consistent with the RCWD. Before reaching the question of mitigation, an applicant will need to justify the impact via the traditional avoidance and minimization analysis. As well, the proposal will be subject to the Section 404 “public interest” review.
Postscript: Due to implementation delays caused by both the USACE issues and a development slowdown (including the Vikings’ abandonment of the Blaine site), some landowners proceeded with ditch cleanout work, which then showed, contrary to the USACE position, that the lateral effect modeling in fact had understated the drainage effect of cleanout. As a result, the St. Paul District now is willing to credit the “hypothetical” ditch cleanout by incorporating it into the “no-action” alternative in the avoidance analysis (see March 18, 2008 USACE correspondence in Appendix). At least one individual permit within the CWPMP area has been issued on the basis of this no-action alternative.
However, the “hypothetically drained” acres are not taken into account in determining Section 404 mitigation requirements. There may be room for the District to move on this question, to the extent such situations may fall under the District engineer’s authority, under the new rules, to award mitigation credit for preservation of wetland resources “under threat of destruction or adverse modifications.” 33 CFR 332.3(h). (However, under the BWSR/USACE MOU, even if other criteria for preservation credit were met, credit would be limited to 12.5 percent of acreage preserved.) Development is proceeding at a more modest pace than anticipated, and the RCWD still expects substantial wetland resource and development benefits from the CWPMP.
- Subsequent CWPMPs
Since 2004, the RCWD has adopted two other CWPMPs, with a third in public review:
- The 53-62 Resource Management Plan, encompassing the part of the Anoka County Ditch 53-62 subwatershed not covered by the Village Meadows CWPMP (December 2006).
- The JD 4 Resource Management Plan, covering about six square miles of developing agricultural land in the Cities of Forest Lake, Columbus and Lino Lakes (Washington and Anoka Counties) comprising the drainage area of Anoka-Washington Judicial Ditch 4 (June 2008).
- The Anoka County Ditch 10-22-32 Resource Management Plan, encompassing about 34 square miles within the Cities of Lino Lakes and Centerville (under review).
Reflecting the RCWD’s Village Meadows experience, the aspiration of these CWPMPs is more modest. They rest on the same technical basis as the Village Meadows CWPMP, namely a wetland inventory, and a classification system based on function and public values assessments. In each case, the goal is establishment of a contiguous, diverse wetland complex denominated as a “wetland protection zone” (WPZ). The intent is to direct unavoidable wetland impacts so they are outside of the WPZ and foster impact replacement within it. However, unlike the Village Meadows CWPMP, which contained a designed outcome and mandated the location of impacts and replacement, these CWPMPs establish incentives by means of wetland impact replacement ratios. For example, impact to wetlands within the WPZ are counted double, while replacement outside the WPZ is discounted by half.
Because the implementing rules for these CWPMPs are not linked to a subwatershed wetland resource outcome “engineered” by the RCWD, they do not use the sequencing flexibility of Minnesota Rules 8420.0650 to eliminate the avoidance and minimization analysis. All landowners must perform an analysis conforming to Minnesota Rules 8420.0520 before impact is permitted.
As the RCWD has scaled back its aspirations, it has semi-formalized its coordination with the St. Paul District. The two agencies collaborate in CWPMP development, during which the goal is concurrence in the technical elements of the assessment and the impact mitigation framework. The District then accompanies the RCWD’s CWPMP adoption process with an approach loosely under the USACE Advance Identification of Disposal Areas (ADID) authority. Under this authority, the USACE district office can identify, in a non-binding manner, jurisdictional areas (wetlands) comparatively suitable for regulated placement of fill, and those less suitable. When the RCWD puts a CWPMP out for public review, and again when it adopts a CWPMP, the St. Paul District publishes notice in the Federal Register (see Appendix). The notice communicates, in effect, that the District concurs in the technical basis and mitigation approach. The concurrence does not bind the District as to development proposals that subsequently come before it, but gives landowners some degree of confidence that RCWD and USACE permitting review will be consistent and will substantially conform to the CWPMP.
- Conclusions: Area-Based Wetland Regulation
These four CWPMPs embody the core principle of area-based regulation. They are based on an understanding of the role that wetlands play in the hydrology and ecology of a given subwatershed. Priority wetland, interspersed upland and buffer areas are identified on the basis of existing or restorable function and public value, and compatibility with local comprehensive land use and open space plans. Regulatory criteria then are adopted that by either compulsion or incentive foster the protection, restoration and enhancement of those areas. Benefits to landowners, in the form of both readier aggregation of developable land and more predictable permitting, are implicitly “bargained” for more protective development rules and RCWD access for vegetative and hydrologic management.
Under what circumstances can a CWPMP create significant value to share between development interests and resource protection? In the Village Meadows case, there was an intersection of two very favorable features: One was development pressure, which created a fairly uniform set of landowner interests across the CWPMP area as to both development time frame and highest use. The second was a large degraded wetland area amenable to successful restoration.
More generally, a CWPMP can add value when two things are true. First, when there is a degraded, fragmented and/or vulnerable resource, whose function and values can be preserved or reliably improved through careful understanding and design. Second, when there is a set of landowners with the interest to underwrite the effort. The urbanizing lands around the Twin Cities, and from Rochester to St. Cloud, are candidates. So is developing lakeshore with fringe wetland. The CWPMP also can be used more modestly in local planning to inventory and assess the wetland resource and tailor development regulations to protect the resource as growth occurs. Areas changing from agricultural use to more intensive uses are particularly good candidates, because we can be relatively confident that the hydrology of drained wetlands in these settings can be successfully restored.
- Village Meadows
- Integration of Wetland and Stormwater Management
Stormwater management requirements, of course, come from several different directions. The PCA, implementing the federal Clean Water Act, administers permit programs for incorporation of post-construction stormwater management facilities at industrial and development sites. Minn. Rules 7090, Minn. Stat. §115.03, 40 CFR Part 122. It also uses a permit framework to mandate that owners and operators of stormsewer systems in urban or urbanizing areas (i.e., primarily local units of government), denominated as “metropolitan separate storm sewer systems” (MS4s), regulate land use and development to limit stormwater impacts. Minn. Rules 7090, Minn. Stat. §115.03, 40 CFR Part 122. Aside from this mandate, most local land use authorities already require management of permanent stormwater impacts as a condition of development permits. A number of municipalities, including most in the Twin Cities metropolitan area, are or will be subject to nondegradation requirements under the Clean Water Act, requiring that they develop and implement plans to reduce stormwater pollution. Minn. Rules 7050.0185. Watershed districts and, in the Twin Cities metropolitan area, some joint powers watershed management organizations also regulate development and require facilities to manage stormwater impacts in perpetuity. Minn. Stat. §§103B.211, 103D.335, 103D.341.
Regulation of stormwater impacts focuses foremost on water quality (primarily regulating phosphorus, for its impacts and as a reliable surrogate for other pollutants), peak flow management, and overall runoff volume. The stormwater management paradigm shifts decisively from large retention basins toward low impact development techniques and the use of natural landscape features for retention and infiltration. By understanding the role that wetlands and lowlands play in regional hydrologic and ecologic systems, a property owner more and more will have opportunities to use wetland restoration, creation and preservation to meet both wetland and stormwater management obligations. In addition, there will be room for collaboration outside of the development or regulatory context between landowners and land use authorities required by federal laws or local watershed plans to manage wetlands as one means of meeting local water quality goals.
The RCWD’s Forest Lake CWPMP is somewhat unusual in explicitly integrating wetland and stormwater regulations. It requires a portion of the stormwater volume control requirement (0.5 inches out of a 2.8-inch standard) to be met by a small category of measures that include reestablishing drained wetlands, restoring degraded wetlands and restoring or conserving adjacent upland as buffer. Rule RMP-2, subsection 8(c).
In coming years the Total Maximum Daily Load (TMDL) program, 40 CFR 130.7, is likely to contribute to the integration of wetland and stormwater management. This Clean Water Act program requires states to identify waterbodies that fail to meet water quality goals, pollutant loading to the waterbody that would be consistent with the goal, and reductions in pollutant loadings from point and nonpoint sources that would achieve the goal. The PCA requires that each TMDL be accompanied by an implementation plan that allocates necessary pollutant load reductions among sources.
These implementation plans are transformed into legally binding obligations for stormsewer system owners and operators through the following language in the NPDES MS4 general permit:
If a USEPA-approved TMDL(s) has been developed, you must review the adequacy of your Storm Water Pollution Prevention Program to meet the TMDL’s Waste Load Allocation set for Storm Water sources. If the [SWPPP] is not meeting the applicable requirements, schedules and objectives of the TMDL, You must modify your [SWPPP], as appropriate, within 18 months after the TMDL ... is approved.
MPCA Permit No. MNR040000, Part IV.D. Similarly, construction sites subject to NPDES stormwater permits (in general, sites larger than an acre) that discharge to a waterbody subject to a TMDL for sediment or a pollutant associated with sediment must:
[D]evelop and certify a SWPPP that is consistent with the assumptions, allocations and requirements in the approved TMDL.... Permittee(s) must incorporate into their SWPPP any conditions applicable to their discharges necessary for consistency with the assumptions, allocations and requirements of the TMDL within any timeframes established in the TMDL.... If a specific numeric wasteload allocation has been established that would apply to the project’s discharges, the Permittee(s) must incorporate that allocation into its SWPPP and implement necessary steps to meet that allocation.
MPCA Permit No. MNR100001, Part I.B.7.
Governing EPA guidance recognizes that often it is not feasible to state numerical effluent limits for stormwater pollutant sources. Therefore it authorizes responsibility for pollutant load reduction allocations to be expressed as obligations to employ Best Management Practices (BMPs). “Establishing Total Maximum Daily Load (TMDL) Wasteload Allocations (WLAs) for Storm Water Sources and NPDES Permit Requirements Based on Those WLAs” (U.S. EPA, November 22, 2002)(see Appendix).
Also, at present the evolving approach in TMDL implementation plans will be to allocate load reductions among local land use authorities (municipalities), and to look to those authorities to effect the needed reductions within their boundaries by means including development and other ordinances.
Accordingly, for the near term, the above SWPPP requirement to incorporate TMDL responsibilities will have more consequence for MS4s than for construction sites. In either case, responsibilities are likely to encompass use of BMPs and not numeric effluent limitations.
Where the pollutant is excessive nutrients or turbidity, and for other pollutants as well, the preservation or restoration of wetland and adjacent vegetated buffer is one tool for achieving water quality improvement goals. A municipality or other MS4 (such as a watershed district) can work toward its TMDL obligation through its wetland regulatory program, as well as its implementation of open space, land conservation and capital improvement programs. In either event, a property owner or developer will be able to benefit from understanding on-site wetlands in their watershed setting and creating a development or conservation plan that reflects that understanding. (Indeed, in some cases wetlands may contribute to downstream pollutant loadings and TMDL efforts might be advanced by hydrologically isolating them.)
To date, fewer than 20 TMDL implementation plans have been approved by the PCA or noticed in draft for public comment. Further, in the typical case, the implementation plan estimates pollutant load reductions that might be obtained from certain categories of actions without identifying on which properties or through what vehicle (e.g., regulation, government restoration projects, conservation easements, cost-share incentive programs) the actions will be implemented. Accordingly, a number of implementation plans identify wetland and/or wetland buffer protection as one potential element, but do not advance beyond this (e.g., Twin and Ryan Lakes (nutrients); Lake Independence (nutrients); Carver-Bevens-Silver Creeks (fecal coliform); Lower Mississippi River Basin (fecal coliform); Lower Minnesota River (dissolved oxygen); Rock River (fecal coliform and turbidity)).
With time, however, wetland management may be integrated with more specificity into TMDL implementation plans. As a harbinger, one might look at the Minnehaha Creek Watershed District (MCWD) watershed management plan. Watershed districts within the Twin Cities metropolitan area must prepare watershed management plans. Minn. Stat. §103B.231. The watershed plan may set standards that cities and townships within the watershed must meet through their own local water plans and programs.
The MCWD plan comprises eleven subwatershed plans. Each subwatershed plan is oriented to achieve a phosphorus goal for the subwatershed’s primary receiving waterbody. Where a TMDL has been established, that is the goal; in other cases the MCWD itself has determined the goal through a TMDL-analogous process. The subwatershed plan then allocates to each municipality within the subwatershed responsibility for a portion of the needed phosphorus load reduction. The amount of the allocation rests on MCWD review, during plan development, of the municipality’s ability to secure phosphorus reductions through its regulatory, housekeeping, capital project, land protection and other tools. The subwatershed plans explicitly identify the restoration and protection of wetlands and vegetated wetland buffer as one means to reduce phosphorus loadings to receiving waters. One could expect that some of these efforts will devolve down to landowners and developers.
Municipalities within the Twin Cities metropolitan area are now preparing comprehensive local land use plan revisions meet a December 31, 2008 statutory deadline. Minn. Stat. §473.864, subd. 2. To be eligible for Metropolitan Council approval, a comprehensive plan must include a local water plan that has been approved by the watershed district(s) within which the municipality lies. As this process unfolds, we will see what regulatory responsibilities, or opportunities, fall to property owners to address water quality through wetland management.