HomeMy WebLinkAboutA003 - Council Action Form dated May 25, 2010 ITEM #: 29
DATE: 05-25-10
COUNCIL ACTION FORM
SUBJECT: ZONING ORDINANCE TEXT AMENDMENTS TO ALLOW SMALL WIND
ENERGY SYSTEMS IN COMMERCIAL AND INDUSTRIAL ZONING
DISTRICTS
BACKGROUND:
In response to increased interest in small scale on-site power production, in August
2009 the City Council reviewed possible solar and wind policies and decided to review
solar and wind zoning text changes separately. The City Council subsequently passed
regulations for on-site solar energy systems in November 2009. Policy option concepts
for wind were then brought forward to Council in February 2010. The Council directed
staff to prepare text amendments to allow wind energy systems in the following four
zoning districts:
1. Planned Regional Commercial
2. Highway-Oriented Commercial
3. General Industrial
4. Planned Industrial
Code provisions facilitating wind energy in these zones are reflected in the attached
ordinance amendments to Chapter 29, Articles 13 and 5. There are currently no
pending requests for wind turbines in residential districts. Because of the lack of active
interest in residential areas, as well as some compatibility concerns, the Council
directed staff to not incorporate residential zones. Currently, there is active interest on a
few properties within commercial and industrial zones.
The proposed ordinance follows the same format as the Des Moines Metro Area
Council of Governments Model Ordinance for Small Wind Energy Conversion Systems.
That model ordinance is generalized to serve as a guide for Des Moines and
surrounding suburban communities. Because there are no federal or state laws
establishing rights for the wind energy industry, cities are allowed to establish more
customized standards based solely upon local policies, such as a city's Land Use Policy
Plan. Accordingly, West Des Moines has passed its own wind energy ordinance; while
proposed regulations are under review in Ankeny. Story County Zoning has also
passed wind energy regulations, but they will not apply to areas within the city limits of
Ames.
Staff has reviewed information from across the United States, including manufacturer
specifications, municipal ordinances, trade journals, conference sessions and actual site
visits. The following documents have been particularly influential in the development of
this proposed ordinance:
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1. Des Moines Metro Area Council of Governments Model Wind Energy Conversion
Systems Ordinance
2. City of Carson City, Nevada wind energy ordinance
3. City of Flagstaff, Arizona (home of skystream wind turbine company) wind energy
ordinance
4. Cascade/Swift rooftop wind turbine model ordinance (a manufacturer)
5. American Wind Energy Association model ordinance
Highlights of Proposed Amendment:
Many of the concepts within the proposed ordinance have been discussed at previous
City Council meetings. Therefore, this report will only summarize new or significantly
revised topics.
Allowed Use:
The foundational issue for the Council involves creation of a code provision for
wind energy as an allowable use. This would be accomplished by adding "wind
energy conversion" to the miscellaneous uses in Table 29.501(4)-7, and
establishing that it is an accessory use and is to be implemented with the new
Section 29.1310. A similar text amendment was previously made to this section
for `solar energy conversion.'
Tower style:
Monopole style towers are required except for General Industrial Zones. The
monopole design has typically been found more desirable for urban areas
because of its more slender, less noticeable profile on the skyline. This is also a
requirement of the zoning code for cell towers. Lattice (webbed) style towers are
more indicative of an industrial area and would give more flexibility to industrial
owners. Monopole towers exponentially increase in cost with added height,
unlike lattice towers. Guyed towers are not allowed under the proposal.
Noise/Vibration-
Whether perceived or real, noise and vibration impacts are by far the most
discussed issue for wind energy systems. The Planning and Zoning Commission
and the City Council discussed this issue many times. In August the Council
discussed imposing minimum lot sizes as a means of addressing the
complexities of sound attenuation. The proposed standards, however, are less
complex because the proposed zones are not residential zones. The proposed
standard requires a manufacturer design of less than 55 decibels, and specifies
that no noise or vibration above the ambient sound level may be detected from a
property within a zone where a system is not allowed.
The proposal further regulates low frequency (inaudible) sound by setting a
minimum design standard requiring that all sound waves emitted from the system
are above 20 hertz. Medical research shows that low frequency sound can
trigger adverse responses such as migraine headaches in sensitive individuals.
This is, however, more likely concern of utility'scale (large) wind turbines, such
as those in rural areas, rather than small wind turbines. Small wind turbines
oscillate at higher revolutions per minute and therefore are not typically
associated with these low frequency sounds. An example of a low frequency
sound would be a bass toned musical instrument. The lowest key on the piano is
32 hertz. The human ear can not detect anything below 20 hertz.
Shadow Flicker:
The proposed standards would also prohibit shadow flicker on or in any
residential structure. This would only be applicable where a proposed system is
on a lot that is adjacent to a residential zone.
Engineer Certification:
The Model Ordinance includes a mandatory requirement for an Iowa
Professional Engineer to certify the structural stability of the system. But,
because this is less of a zoning issue, the proposed ordinance allows the
Building Official to determine whether or not an engineer certification is required.
Feasibility Study:
The draft ordinance reviewed by the Planning and Zoning Commission had
language recommending a wind resource feasibility study. However, because
this would be for recommendation purposes only, the language was removed
from this proposed ordinance, and will instead be incorporated into a citizen
informational packet.
Setbacks:
There is little evidence that freestanding systems collapse any more often than
buildings. Typically, wind turbine towers meet a much higher wind resistance
engineering standard than do buildings. Much discussion was held about a
process where two neighboring property owners could agree on a reduced
setback through a Special Use Permit. However, with the larger lots more typical
of commercial and industrial zones, this option was removed. The current
proposal is to require a setback distance of 110% of the total height.
Minimum Lot Size:
In August 2009, the City Council discussed the benefits of using minimum lot size
as a way to account for many of the complex issues surrounding wind energy
systems. However, the discussion was centered on residential areas. Because
wind energy is not being proposed for residential zones, the minimum lot size
requirement has been removed.
Front Yard:
The front yard prohibition was removed because wind energy is not being
proposed for residential zones. The front yard is the area between the building
and the street, regardless of the minimum setback line. Extensive parking and
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landscaping areas are typical of commercial and industrial areas. Therefore, a
prohibition in the front yard would pose a challenge for the majority of lots in
these areas.
Number of Systems per Lot.-
The quickly evolving small wind industry has led staff to propose more flexibility
in the number of systems per lot. Some early discussions indicated a desire to
control the density of wind turbines to prevent a dominance of wind towers in the
skyline. Some discussions at Council in August also considered the aesthetic
importance of the entrance corridors to Ames. The proposal leans heavily on the
Des Moines Metro model ordinance with a sliding scale depending on lot size.
The text proposed to the Planning and Zoning Commission mirrored the Des
Moines model by limiting the number of towers taller than the tallest building on
the lot. The base limit for horizontal axis turbines can be exceeded under
collocation provisions included in the proposed standards. For example, a wind
turbine mounted on a parking lot light would not be included in the maximum
number allowed per lot.
Based on public feedback at the May 5 Planning and Zoning Commission
meeting, the Commission removed the limitation that would prevent more than
one system taller than the principal building on the lot. The attached proposal
reflects that change. It was determined that proposed setback requirements and
electrical capacity limitations would achieve a similar result.
Land Use Policy Plan:
Within the City's adopted Land use Policy Plan, Goal 3 of "Goals for a New Vision,"
regarding "Environmental-Friendliness" is supportive of this text amendment, because it
opens small wind energy as a possibility for property owners to use for conserving
traditional energy sources by generating supplemental power on-site.
Goal 4 of "Goals for a New Vision," focuses on a "greater sense of place and
connectivity" and "assuring a more healthy, safe and attractive environment." The
proposed ordinance is consistent with this goal because it seeks to allow small wind
energy equipment in a way that is sensitive to the character of the surrounding built
environment.
Net Metering:
This zoning text amendment does not constitute an approval of a net metering tariff. A
net metering tariff proposal will be brought forward later by Ames Electric Services.
Council Goals:
One of the City Council's goals is to "Go Green and Promote Environmental
Sustainability." One way to quantify sustainability for the City is to reduce demand for
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electricity. An additional element of the Council's goal is sustainability awareness. The
proposed text amendment is a flexible set of standards for wind energy systems which
allows many possible options for owners. In addition, the proposal would facilitate the
handful of active inquiries that have already been brought to staff.
Recommendation of the Planning & Zoning Commission. At its meeting of May 5,
2010, by a vote of 7-0, the Planning and Zoning Commission recommended that the
City Council adopt proposed text amendments allowing wind energy systems in the
PRC, HOC, GI, and PI zoning districts. This would amend Chapter 29, Articles 5 and
13.
ALTERNATIVES:
1. The City Council can adopt the attached text amendments allowing wind energy
systems in the PRC, HOC, GI, and PI zoning districts, which would amend
Chapter 29, Articles 5 and 13.
2. The City Council can modify the proposed text amendment.
3. The City Council can decide not to adopt the proposed text amendments.
4. The City Council can seek additional public input or information from staff before
making a decision.
MANAGER'S RECOMMENDED ACTION:
As noted above, language recommending a feasibility study was included in the
ordinance reviewed by the Commission, but was eliminated from the draft now before
the Council. Also not included in this draft, but reviewed by the Commission, was
language pertaining to certification by Underwriters Laboratories and American Wind
Energy Association. This was removed because it is already addressed under building
permit review.
In February the Commission recommended a conservative approach to the City Council
that would begin to open opportunities for wind energy within the City of Ames. The
Council directed staff to develop standards for zoning districts actively requesting wind
energy systems. Staff believes that the attached draft ordinance is consistent with
direction from the City Council.
Therefore, it is the recommendation of the City Manager that the City Council accept
Alternative #1, thereby adopting the attached text amendments allowing wind energy
systems in the PRC, HOC, GI, and PI zoning districts.
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