Thou Shalt Review Ordinances…And Then What?

Communities covered under Phase II of the National Pollutant Discharge Elimination System (NPDES) are wrapping up activities under the first round of permits. If the first five-year permit cycle was about setting up programs, the second permit cycle will focus on program assessment and fine-tuning. EPA anticipated this evolution, including the following language: “In developing your program, you should consider assessing existing ordinances, policies, programs, and studies that address stormwater runoff quality.”

Ordinance and code reviews are an increasingly popular tool to identify and address the impact of land development standards and zoning codes. Similarly, communities are reviewing codes for barriers to low-impact development or overarching sustainability goals. This article provides information on conducting code reviews and some of the more surprising findings related to conventional zoning codes.


The first step in preparation is to determine how the review results are to be used. At the most basic level, reviews can be revelatory, where the results are used primarily for education and outreach. Second, cities can perform code audits in concert with a local planning effort. The most consequential audits are launched as part of regulatory programming such as Phase II, combined sewer overflow control plans, and total maximum daily load implementation plans, where code changes are required in order to meet regulatory standards.

In addition to having someone from planning and zoning walk you through zoning codes, the following pre-code audit steps can help streamline the process:

  • Determine regulatory requirements for site design not presented in the zoning code. Ask the city or county engineer to bring stormwater performance standards; hillside development standards; and building, utility, and plumbing codes.
  • Find out if changes to zoning and planning are already underway to meet new rules on water conservation, “green streets,” hazard mitigation, and the like.
  • Chart out ahead of time whether adopting code changes can get you additional benefits–for example, points or priority funding for state infrastructure projects.
  • Prepare to exploit cross-program actions. For example, a code change to increase and track tree canopy for stormwater management may also meet climate initiative goals to reduce urban heat island effect.
  • Finally, because changes to legal code may be involved, make sure the legal department and elected official are involved and aware of possible changes needed.

In addition to the code review itself, there are several parallel activities to include in a code audit. Windshield surveys and walking tours are helpful in determining how codes and regulations are translated into actual projects. Second, the use of maps is important, because the relevance of a certain code category can hinge on how large an area the zone covers or on its location. Finally, interviews are needed to ascertain whether code language that appears to be a barrier or opportunity has any meaningful on-the-ground influence.

Photo: Lisa Nisenson
Shared parking relieves the landscape of additional pavement. Here, a parking space was “found” on existing impervious surface.

The first generation of code reviews, by and large, tended to recommended changes within the existing code structure–for example, revised setbacks and parking ratios. These recommendations, while applicable, seemed incomplete, because Euclidian zoning codes are implicated in driving excess land development and consumption, as detailed below. Euclidean zoning refers to the practice of establishing codes for single-use districts–for example “R” and “C” zones for residential and commercial zones, respectively. These codes control uses, bulk and placement of buildings, and parking, among other things.

Moreover, many early code audits focused on a single objective–for example, reducing runoff on individual lots or rooting out excess parking from code. Communities today are tackling community design issues on several fronts, and reviews need to address multiple scales and multiple objectives simultaneously. One of the most effective methods for capturing multiple scales of development and impacts is, conveniently, from the watershed’s point of view.

Early versions of code reviews with the watershed in mind focused on impervious surface, with recommendations largely centered on reducing the percentage of impervious cover. However, one of the most direct methods of reducing the share of impervious cover is to grow lot sizes. Success at the lot level can thus become a wider disturbance at the watershed level. This same standard also penalizes compact development, where building blueprints intentionally maximize site coverage with the aim of reducing the overall development footprint. To overcome the site-versus-watershed tension, we asked the impervious cover question in two ways:

  • What drives excess impervious cover at the larger basin level?
  • What drives impervious cover at the site level?

As it turns out, these questions are really looking at efficient use of land, which is also at the core of code reviews to address walkability, economic development, transportation, and reductions in energy use.

Series of Questions
Investigating site-level impacts that arise from land development standards is challenging enough, but how does one assess impacts on a larger scale? This involves looking at what drives land development patterns. Table 1 shows examples of “pattern” elements within codes, and sample questions.

How does code affect open space?
On individual sites, bulk requirements such as setbacks and landscaping requirements begin to shape “open space” on a lot, while prescriptions for dedicated open space appear in language for larger residential subdivisions and office park–type projects.

One of the strongest actions related to open space is to weave open space and parks into a green infrastructure program, which begins to define the services rendered by conserved land. Quantified details can help support and defend stepped-up code language for land acquisition and restrictions on ecologically sensitive lands.

In urbanizing and urban areas, parks, and open space are increasingly supplied by developers. Although open space is important to meet multiple community objectives, requirements, when rendered through individual projects, can lead to vast projects with open space that is more about quantity than quality. These largely private parks may supply land for infiltration, but on the whole can they can also expand the development footprint

Rural housing is one of the more vexing dilemmas for urbanizing areas; density can range from four houses per acre in rural codes to one house per 40 or more acres. The “right” density for rural housing is not so much a code issue, but rather one that entails planning and rural economic development. We recommend caution when applying new cluster subdivision codes. Although these codes can be helpful in shaping entitled or planned residential areas, they will not supply relief where unplanned development is the underlying environmental problem.

Finally, many codes refer to park and open space design manuals. We scanned several manuals and found that they rely on conventional drainage methods. Retooling these manuals will likely require a separate audit and revision process where parks are redesigned to serve a green infrastructure role.

How does code affect infill and redevelopment? Redevelopment is one of the most powerful tools for watershed restoration. If your city drains into an impaired waterway, the retrofit of an older site with improved water management provides a direct benefit. Plans for redevelopment hit code barriers when a project triggers updated code directives, which have by and large increased over time to require more parking, larger setbacks, and increased frontage.

Photo: Lisa Nisenson
Codes often require elevated curbs for landscaping in zoning chapters devoted to parking.

Most communities have developed special zoning codes for redevelopment areas, namely central business districts, historic downtowns, and neighborhoods near transit stations. While these district codes help orchestrate the public and private elements of placemaking, any audit should examine whether the code process itself is a barrier. For example, downtown codes might allow shared or joint parking only if a developer conducts an additional study and only if the same number of parking spaces is supplied. The time and expense yield limited (or no) benefit and represent a missed opportunity to reduce parking impervious cover.

During windshield surveys, we found that redevelopment districts with location advantages, such as downtowns, waterfronts, or transit station areas, were transformed during the recent building boom. The next generation of redevelopment will take place in aging strips and corridors that present the next set of economic development, planning, and code challenges. Because these older projects send large volumes of untreated runoff into waterways, redevelopment of these sites is as much an imperative for watershed managers as it is for the economic development department.

How does code affect compact development? Framing questions around compact development reveals how code language drives inefficiencies in land platting and development. Within the “land development” chapters, code audits typically examine the cumulative effect of several “bulk” elements, including setbacks, frontage requirements, building footprint limitations, and height limitations.

Setbacks are likely to become more of an issue for joint water-land codes as best management practice (BMP) requirements grow. One unexplored planning issue is what happens when a state adopts a larger design storm. In essence, something has to grow to handle the additional volume. If a state or locality focuses primarily on bioswales and biofiltration, setbacks will need to grow, which can send developers in search of larger sites. For this reason, municipalities need to work with engineers to ensure a full array of BMPs are adopted and readily available, in particular for compact development and redevelopment.

Codes directing higher-density residential projects need special attention, given the important role multifamily structures play in shrinking the development footprint. Developers have been required, over time, to supply an increasing number of amenities onsite: parking, visitor parking, parking for recreational vehicles, landscaping, open space, recreational space, and so on. The extra space needed may have the effect of forcing higher-density projects to the fringes of town where land is available. As part of the code review, cities can map major multifamily projects over time to see if or how code has affected location.

How does code affect use mix? Use separation is a hallmark of Euclidean code, which results in a larger development footprint because components of daily tripmaking can be accessed only by car. This, in turn, increases the pressure to supply impervious surfaces for auto movement and storage.

Within code categories, there can be wide variation in the number of uses allowed. Residential codes tend to be the most restrictive, while many commercial zones contain dozens of both commercial and residential uses. With longer lists of allowable uses, developers and building owners can use existing buildings even as market demand changes, lessening the need to build anew.

Use mix proved to be the most difficult topic to address. On one hand, phrases like “location, location, location” and “retail follows rooftops” suggest the market actually works to deliver a meaningful use mix. However, a scan of codes and site visits show these maxims interpret proximity through an auto-access lens, with little regard for the additional auto habitat required. Other code barriers included the requirements for walls between unlike uses and building placement that make pedestrian tripmaking inconvenient.

How does code affect mobility-related impervious cover? The intersection of code language and street design is contained in a variety of state manuals, standards, plans, and codes. Street design requirements are often presented pictorially as “cross sections,” illustrations that provide the width and dimensions needed for roads, shoulders, rights of way, sidewalks, curbs, and medians. The cross sections are typically presented within a “functional classification” system, moving from low-volume rural roads to collectors and arterials to highways. Other sections detail materials that can be used in road construction–for example specifications on concrete and its composition.

Photo: Lisa Nisenson
Courtyard housing codes supply less space than conventional codes, yet emphasize quality of space rather than quantity. This can include stormwater management while reducing the overall footprint of development per unit.

The entire issue of street design, widths, and green streets is a hot topic. The concept of mobility is gaining traction not just as the opposite of congestion, but also to establish transportation systems comprising multiple modes. In gauging environmental performance, one stakeholder’s sidewalk can be another stakeholder’s excess impervious cover. A larger-scale assessment of the multimodal transportation system is key to resolving whether imperviousness is excess or essential.

The sidewalk example might be resolved through pavers and infiltrative materials. However, street standards and fire codes often limit acceptable materials for streets, driveways, and sidewalks unless these materials are adopted by the state department of transportation. Check the status of acceptable materials and specifications with engineers. Also check any guidance on allowable costs for use of infrastructure funding. While the recent stimulus funds set aside 20% for green techniques, current manuals often restrict expenditures to a handful of conventional building materials and conveyance methods.

Perhaps the least-explored issue related to streets is their treatment on the overall impervious cover balance sheet. If developers are seeking rural areas or larger lots to meet water rules, the project may appear to have “zero impact,” even as the roadway system grows to serve the larger development footprint. During the code review, your team may want to forecast road expansion under various growth scenarios.

How does code affect parking and loading? Like street design, parking occupies a conspicuous spot on the impervious audit radar. Almost all code reviews recommend reducing the amount of parking in standards. However, there is no magic code change wand that reduces spaces without some pushback from retailers, landowners, and stakeholders concerned about spillover parking. We found that successful efforts often began with parking space utilization studies. These studies look at the degree of over- and undersupply, how to handle peak parking events, and management options within a “parking-shed.” Parking studies usually initiate a broader effort to “find” parking spaces on existing paved areas. Even so, there are a couple of quick fixes. For example, basing parking requirements on staffed space rather than gross square footage can reflect demand while reducing spaces needed.

One of more surprising findings was the effect of loading requirements on land consumption. Loading, which is typically presented in the parking code, determines the amount of space needed for truck parking bay sizes and maneuvering room. For safety reasons, codes require that all trucks be able to maneuver totally onsite. Where a business is served by larger trucks, site design must consider this maneuvering–and space. Many cities are revisiting shared loading, alleys, and on-street delivery to lessen the space needed for loading and deliveries, or are offering exemptions for lower-volume streets.

How does code affect environmental site design? Certain key sections of code–notably landscaping, parks, environmental protection, and setback requirements–will host the most immediate onsite opportunities. Code sections related to building standards will also become important focal areas for water management. If your code is on the Web, use the search function to find code sections dealing with “landscaping,” “plantings,” and other terms potentially related to green design.

Although green design has been entering comprehensive planning language in a big way, the extension to code language has been less complete. Strengthening “purpose and intent” statements can be a first step to spur better code language. In other instances, green planning and code language are often so vague as to be easily dismissed. During the code review, seek ways to transform mildly supportive language into code that actively promotes desired environmental practices.

Likewise, determine whether low-impact development practices can be woven into smaller permitted activities. Because most stormwater controls are required only with disturbance of one acre or more of land, examine the viability of requiring some measure of environmental practices for smaller remodeling projects.

Increasingly, code language lists instructions not only on plant selection and installment, but also on long-term maintenance. The addition of maintenance is a critical recommendation for code changes undertaken to meet environmental standards and NPDES Phase II. Note, however, that placing maintenance in code introduces new responsibilities for code enforcement, training, and reporting systems.

How does code affect the overall environmental footprint? Small-area planning. Through our code reviews, perhaps the most impressive finding of all was the environmental power of small-area planning. Efficient land use is the result of orchestrating public and private site-design elements for new development and redevelopment alike. This is the antithesis of Euclidean code, which treats each site as an autonomous unit that must be planned for every contingency. These contingencies add land to meet “just-in-case” scenarios related to parking, loading, line of sight, and even stormwater management.

While new small-area codes will be important, one main shift will entail adopting new modeling and compliance measurement systems. Models such as the Smart Growth Index are evolving to recognize the larger environmental benefits of density and redevelopment. Larger-scale modeling efforts will also be needed, in which stormwater management will be a combination of onsite treatment, public systems, and shared treatment practices. This is where sub-basin planning is essential, and it can be tied into land use, capital improvement, and transportation plans.

For small-area plans, new codes are often developed as optional overlays. If your municipality is adopting an overlay to meet environmental regulations, be advised that a mandatory, rather than optional, overlay may be required. Likewise, establish a variance monitoring system to ensure compliance over time.

Developing Recommendations
The main objective of an audit is to correct deficiencies. Code reviews and audits are likely to spot far more deficiencies than a municipality can tackle in the short term. Moreover, some changes will require extensive stakeholder meetings and funding. As such, the following list presents a snapshot of how recommendations can be grouped.

 “Quick Fixes” and Hot Spots. Identify ordinance language that needs to be addressed in the short term with little or no disagreement among stakeholders.

Process Changes. Address process changes to streamline preferred practices. Within this category, also consider a running list of studies needed to support reform.

Menus of BMPs. Consider the development of several menus of BMPs to address the wide variation of environmental, developmental, and economic conditions. As a start, you might develop a new menu for a downtown area or mall retrofit.

Changes that Require Higher-Level Action. Develop a list of items that will require action at the state level or in coordination with a standard-setting organization.

Small-Area Planning. Develop a list of recommendations for small-area plans in the pipeline, or for the small-area planning process, to strengthen environmental performance. Be prepared to recommend new small-area plans based on environmental parameters to address flooding or sub-basin-level approaches to runoff management.

Economic Development. Determine where capital improvement projects might be used to attract green redevelopment and development.

Cross-Program Compliance. Make a list of BMPs that can serve to “check many boxes” among planning and compliance efforts. Note that permit reporting schedules and performance standards geared to different outcomes can complicate this activity; however, meeting multiple compliance activities with one action can be worth the effort.

For More InformationThe Local Government Commission has created the First Stop Shop for Water Resources, which contains links to several documents and products linking land and water resources.

A December 2008 draft of Watershed-Based Strategies for Ventura County is available online.

The US EPA Development Community and Environment Division (DCED) publications page contains links to numerous resource guides on environmental design. DCED will soon release a code audit guide to support watershed management and low-impact development.

About the Author

Lisa Nisenson and Clark Anderson

Lisa Nisenson with Nisenson Consulting in Sarasota, FL, previously worked in EPA’s Office of Policy, Economics, and Innovation. Clark Anderson is the director of the Western Colorado Legacy Program for the Sonoran Institute.

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