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ments for traffic impact and suggest design changes to site plans.
<br />One recent report, for a Taco Bell restaurant along a state
<br />highway, involved a capacity analysis of existing and proposed
<br />roadways to accommodate the estimated 1,200 additional vehicle
<br />trips generated by the 2,000-square-foot facility each day. On the
<br />basis of the analysis, the consultant recommended changes in the
<br />driveway location and sufficient setback to allow for a future five-
<br />lane roadway. He also proposed that the city plan for a frontage
<br />road that would cross the 1.5-acre site and link to other adjoin-
<br />ing properties in the same block as the proposed restaurant.
<br /> PubBcfacilitles. Community facilities impact analysis looks
<br />at the adequacy of various types of public facilities such as parks,
<br />schools, fire stations, and libraries, although the need for these
<br />facilities may be attributed more to overall community growth
<br />than to one or more developments. For example, the need for
<br />library expansion may vary considerably, based On the .
<br />educational and socioeconomic conditions in a commun,ty.
<br /> One mistake planners sometimes make in analyzing commu-
<br /> nity facilities is using standards that aren't tailored to the locality,
<br /> says Burby. Some communities provide a lot of recreation
<br /> privately and don't need the sa,rn.i~oPark acreage standards as a
<br /> densely developed urban area. grab a standard from the
<br /> National Parks and Recreation Association without thinking how
<br /> appropriate it is can produce results that make planners look silly
<br /> and lay them open to challenge in court," he says.
<br /> More typically, the impact analysis will examine water supply
<br /> and distribution and sewage collection and treatment. The
<br /> constraints are at two levels: distribution and collection, and
<br /> water supply and storage and wastewater treatment capacity. The
<br /> first level may be evaluated using computer simulations of
<br /> distribution and collection systems. The second level involves a
<br /> highly technical analysis best performed by a professional
<br /> engineer. As with all impact analysis techniques, the assumptions
<br /> used will affect the outcome. How much water or wastewater a
<br /> new development requires or adds each day in gallons per capita
<br /> or per employee can greatly influence the determination on
<br /> whether an existing facility can satisfy the additional load.
<br /> Stormwater runoffanalysis looks at the capacity of existing
<br /> natural drainage channels or pipes and helps in the design of a
<br /> detention facility--a holding tank or pond--that will
<br /> accommodate the runoff from the land's changed surface
<br /> characteristics and slowly release it after a storm. Such facilities
<br /> typically are designed so that post-development runoff does not
<br /> exceed pre-development runoff during peak storm events.
<br /> Special impacts. Other analytical techniques may be more
<br /> specialized. They may address the development's impact on:
<br /> · , air quality near the development by predicting the change in
<br /> the concentration of pollutants in relation to federal standards;
<br /> ,~ noise by predicting the changes in noise levels (frequently
<br /> traffic-related), the frequency of occurrence, and the number
<br /> of people affected;
<br /> ~ the potential for exposure to natural or man-made hazards,
<br /> such as increased likelihood of flooding or exposure to toxic
<br /> chemicals.
<br /> ~'here environmentally sensitive areas such as wetlands are
<br /> involved, impact analysis could extend to assessing the potential
<br /> for changes in the diversity and population of wildlife and
<br /> vegetation of either common or rare and endangered species.
<br /> Comprehensive Guidelines
<br /> In 1990, Lebanon, New Hampshire, amplified part of its zoning
<br /> code by adopting a very comprehensive set of locally developed
<br />
<br />impact guidelines. The guidelines apply to planned-unit
<br />residential developments but not to impacts of site-specific
<br />development on one parcel. In New Hampshire, the latter are
<br />covered by separate site plan review statutes. Applicants for such
<br />developments must address "adverse impacts on the City of
<br />Lebanon by the PURD." The guidelines cover fiscal impact,
<br />public service and utility, traffic, and natural resources and
<br />environmental quality impacts, and their relationship to the city
<br />plan. They also instruct the developer on how to prepare the
<br />impact statement, including methodology and format for
<br />presentation of results. The applicant must also propose
<br />"mitigating measures. · · to make substantial reductions in the
<br />adverse effects of the project where it is feasible to do so."
<br /> Lebanon's codes, says city planner Kenneth Niemczyk,
<br /> previously "required analysis of projects, but gave no guidelines.
<br /> I suggested to the planning board that they adopt guidelines so
<br /> that the impact reports would be more consistent in the
<br /> presentation to the board. This would make it easier to
<br /> understand these reports." In Lebanon, it can take up to a year
<br /> to gain development approval "for a really massive project."
<br /> One example of how the impact guidelines have been used
<br /> involves a large residential development with two golf courses and
<br /> a small commercial development. "In order to implement it,"
<br /> Niemczyk says, "the developer needed to bring sewer and water to
<br /> the site." Initially, the city wanted the developer to oversize the
<br /> lines, but, as a consequence of the review, the city council
<br /> ultimately decided against extending the lines. "They didn't want
<br /> the development that could have occurred with the expanded
<br /> lines," Niemczyk says. As a result, "the development didn't go in."
<br /> The slowdown in the New Hampshire economy over the
<br /> past several years has meant "the guidelines haven't been used
<br /> very much," says Niemc'zyk. "Things have gone very flat." But,
<br /> he adds, the guidelines have "allowed the planning board to
<br /> review impacts that go beyond the borders of the development.
<br /> It helps them to understand the big picture and how this
<br /> development fit into the big picture."
<br />
<br />Tips and Caveats
<br />Planners interviewed by Zoning News had the following tips and
<br />warnings for communities intending to make impact analysis
<br />procedures part of their development reviews.
<br /> Develop a sereenlng process and checklist for all
<br />developments and publlsh the results. Planners should be
<br />comprehensive by conducting a screening process to identify
<br />potentially significant impacts, says Ray Burby. They should
<br />"pay attention to putting in place a system that identifies the
<br />important impacts, which can change from project to project.
<br />There has to be some type of scanning system or checklist so
<br />you don't neglect to consider an infrequently occurring
<br />impact." An example, says Burby, would be hazardous materials
<br />use. "Very few land uses are involved with hazardous materials,
<br />but when they are involved, it is important to consider thc
<br />effects of an a'ccidental spill of material."
<br /> Gray Smith, an architect and planner in Philadelphia who
<br /> performs impact reviews, favors a checklist approach because of
<br /> its fairness and openness. "The checklist would have to be
<br /> applied to every type of development that has to be looked at by
<br /> the planning commission for their review," he maintains. "The
<br /> results of that analysis have to be published." This provides a
<br /> "checkpoint, starting at the beginning, where affected citizens
<br /> have a role to play in the impact review process. It would
<br /> educate the public so they would understand the rationale
<br /> behind why something is going to happen in their
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