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Work Session Minutes of the Town of Cary, NC Subject: Community Appearance Manual Tuesday,
March
1, 2005
120 Wilkinson Avenue, 2nd Floor Web
Site: www.townofcary.org
Mayor
McAlister called the work session to order at Present:
Mayor Ernie McAlister, Mayor Pro Tem Jack Smith, Council Members Michael
Joyce, Jennifer Robinson, Julie Robison, and Nels Roseland Council
Member Marla Dorrel arrived at Jeff
Ulma of the Planning Department stated that one of the implementation
steps in adopting the Town Center Area Plan (TCAP) was to look at the
implications of the various environmental requirements for water quality
and storm water. Mr. Ulma referred council to the following summary which
reviews the process undertaken by staff. Background On
Downtown
Stormwater Study In
April 2003, the Town contracted with Tetra Tech, Inc., to develop a
stormwater management plan for the Town Center Area. A key focus of the
project was to recommend a management approach that meets state and
federal stormwater requirements while supporting the adopted urban
redevelopment and economic development objectives. To achieve this vision,
the Town will need to address the TCAP’s potential hydrology and
pollutant loading impacts, and plan appropriate mitigation actions.
Regulatory drivers include nitrogen load targets imposed as part of the
Neuse Nutrient Sensitive Waters rule for Total Maximum Daily Load (TMDL);
source water protection regulations in the Swift Creek watershed; Phase II
stormwater requirements; and protection of water quality, channel
stability and physical habitat in the Coles Branch, Crabtree, Reedy Creek,
Swift Creek, and Tetra
Tech conducted six primary tasks on behalf of the Town
Task
1 Impact Analysis evaluated the change in pollutant loading and stormwater
volume expected to result from build out of the TCAP.
Task
2 Mitigation Analysis evaluated Best Management Practices (BMPs) to
mitigate impacts to achieve goals, and recommended the optimal set of BMPs
to use for each of the land use categories for the TCAP. Tetra Tech used
its Site Evaluation Tool (SET) model to conduct the impact and Mitigation
Analysis. Task
3 Engineering Analysis evaluated four example development projects in the
Town of Task
4 evaluated existing stormwater infrastructure in the Town Center Area and
determined planning level cost estimates for infrastructure improvements
required to handle the increased runoff volume associated with the TCAP. Following
the conceptual evaluation of single-site BMP applications (Task 3) and the
existing stormwater collection system (Task 4), a conceptual fiscal
analysis of preferred BMPs and peak attenuation facilities applied
throughout the study area was performed for Task 5.
This evaluation allowed a comparison of single site BMPs,
multi-site and regional applications, including cost in meeting required
targets and potential obstacles or constraints for implementation. Task
6 used multiple criteria—from state regulations, Town plans and
policies, fiscal impact, and overall feasibility—to evaluate the
different stormwater management goals and options and select a preferred
alternative. The
presentation will cover the technical approach, technologies evaluated,
findings of the analysis, and the recommended Town Center Area Stormwater
Management Plan. Project
Schedule
Key
Points 1. The stormwater regulations are complex and can be difficult to
meet on highly impervious sites. 2. The TCAP and water quality goals will not easily be achieved. 3. The current approach to stormwater management is the most cost
effective at this time. 4. Costs may become higher over time as additional state and
federal regulations are implemented. 5. Redevelopment of currently developed sites is preferable to new
development or expansion of under-developed sites. 6. By conglomerating sites property owners may be able to achieve
more flexibility in meeting stormwater goals and share some costs. 7. Stormwater control is part of the cost of doing business in
urban areas. Mr.
Ulma introduced consultant Kimberly Brewer from Tetra Tech who worked with
staff on the vision of stormwater management for the Town Center Area. Ms.
Brewer stated that the Swift Creek Land Management Plan was adopted in the
1980s by local governments for stormwater treatment and
reviewed the regulatory requirements for the Town Center Area. (A copy of
Ms. Brewer’s PowerPoint presentation is attached to and incorporated
herein as Exhibit A; a
copy of Tetra Tech’s February 2005 Town of Cary Town Center Area
Stormwater Management Plan Final Report is attached to and incorporated
herein as Exhibit B.) Mrs.
Robison asked if the 3.6 pounds per acre per year preliminary nitrogen
loading goal set by the staff keeps the Town within the parameters adopted
by the Swift Creek Management Plan. Ms. Brewer replied yes and stated that
the reason for the 3.6 is because staff wanted to set a performance
standard that would have less environmental impact. Mrs.
Robison asked about the mitigating element. Ms. Brewer said that
impervious and treatment caps were set and staff is going beyond the
treatment caps and using good BMPs. Betsy Pearce of the Engineering
Department added that the proposal is to require that developers meet the
3.6 nitrogen loading which is much more stringent than requiring them to
meet the 70 percent impervious cap and allowing nitrogen loading of 10
pounds per acre per year. Mrs.
Robison asked about the imperviousness with the 3.6. Ms. Brewer responded
that meeting the 3.6 nitrogen target and all of the other regulatory
requirements for the Swift Creek Water Shed allows for flexibility on the
30-40 acres of commercial development that are planned to exceed 70
percent impervious. Mr.
Roseland asked if that goal is captured in Town ordinances or whether it
is a starter goal. Ms. Brewer stated that it is a starter goal. She said
that state regulation establishes a capacity of 10 pounds per acre per
year for non residential development. If developers are unable to meet the
goal they can buy down to the 3.6. She said that staff is recommending
stricter goals and not allowing the buy down option. Ms. Pearce added
that the Town currently allows the buy down option. Mrs.
Robinson asked if setting a stricter goal of 3.6 and allowing developers
to use more impervious surfaces requires state approval. Ms. Brewer
replied that permission is only required for areas covered by the Swift
Creek Water Management Plan and that the Town would not have to ask for
permission in the entire TCAP. Ms.
Brewer said that there isn’t that much land in the TCAP that is in Swift
Creek Area that goes over the 70 percent. Mr.
Roseland asked about the code language. Ms. Pearce replied that the code
is currently in line with the state and allows the buy down option.
Ms.
Dorrel asked about the staff’s preliminary goal. Mr. Ulma responded that
the goal was set for testing purposes to provided Tetra Tech with
something to work from. Mr.
Joyce asked if the area zoned to allow 93 percent impervious was outside
of the Swift Creek Area. Ms. Brewer said that most of the high
imperviousness is outside of the Swift Creek Area because most of the Town
Center Area remains low density residential. Mrs.
Robison asked about the workings of dry wells. Ms. Brewer explained that
there is a media underneath the surface that contains sand or gravel which
stores and then evaporates the water. What is not evaporated goes into an
under drain leading to a down spout. She said that dry wells are very
expensive. Ms.
Brewer said that the goal of 3.6 can only be met if existing impervious
and new and future impervious development is treated in the future.
Stormwater coming off of an existing area has to be controlled and
treated. She said that in order to meet the 3.6 goal you have to treat the
entire site and go back and retrofit the existing area. Mrs.
Robison asked if the scenarios in the presentation were only for the part
of TCAP that is in the Swift Creek Area or if the preliminary goal is to
be applied to the entire area. Ms. Brewer responded that the formula
applies to the entire Town Center Area. She said it is stricter throughout
entire Town Center Area in order to gain flexibility in other areas. Mr.
Roseland asked about controlling stormwater in the area. Ms. Brewer said
with the existing rules you can redevelop the entire area but you are only
required to apply the mitigation to any site expansion to achieve the 3.6
of the entire site. Mrs.
Robison asked if the formula shows the type of BMPs necessary for the
nitrogen conditions. Ms. Brewer replied yes. She said that they
tested optimum levels on sites that are already developed in Ms.
Brewer said that under existing regulations you have to control the peak
flow to the pre-development condition. She said that the Town will be
treating such a volume of water that more water will be stored than is
needed. Ms.
Dorrel asked about the peak discharge. Ms. Brewer explained that the
highest level of water is the peak discharge. She directed council to that
graphic on volume control in the Tetra Tech report where you can see a
difference between what is required and what the Town is storing. Mr.
Joyce asked about the acreage for the Town Center Area. Ms. Brewer stated
that the acreage is about 1.5 square miles. Mrs.
Robison asked if a simulated model was used for the study. Ms. Brewer said
they took an actual building and simulated the nitrogen target. Mrs.
Robinson asked about the options for achieving an ultra urban design. Ms.
Brewer responded that there isn’t enough room on the site for
bioretention cells when you have a site with a lot of imperviousness. She
said that a complex alternative would be to build something underneath of
the building. Mr.
Roseland asked about the estimated costs for existing infrastructure
improvements. Ms. Brewer said they did not look into that. She said that
they estimated a cost for the public infrastructure assuming full buildout,
but the estimate provided is very high. Ms.
Brewer said that the state is in the process of developing a new formula
for sites with nitrogen buy down and it will probably be adopt by the
fall. She said that the regional pond is the least feasible alternative
and that there are new guidelines from the Environmental Protection Agency
(EPA) that make regional ponds next to impossible and difficult to build.
She said that is why staff looked closely at shared facilities. Ms.
Dorrel asked what is included in the costs. Ms. Brewer responded that the
costs include construction and regional facilities, but not operational
and maintenance expenses nor the land that would have to be bought. Mr.
McAlister asked if the development of shared facilities has ever been
pursued by other local government. Ms. Brewer responded that there were
none in Mrs.
Robison left at Mr.
Roseland asked Ms. Brewer to elaborate on what is meant by considerations
for BMP’s and stormwater controls used to offset the effects of
redevelopment in the Town Center Area. Ms. Brewer said that they were
evaluating the impact of the TCAP at build out and how to mitigate that
impact. She said that they were trying to avoid major downstream problems
with the stormwater volume. Mrs.
Robinson asked about the BMPs to be used for shared facilities, the cost
difference, and sharing among multiple parcels. Ms. Brewer said it would
depend on the number of parcels sharing the facilities. Mrs.
Robinson asked about integrating the BMPs of the shared facilities so that
they look like amenities to the community. Ms. Brewer stated that a pond
as a water feature could be used. She said that the key is to maintain the
water feature so that it does not become unsightly because if it is not
maintained it can become a big muddy pond. Mayor
McAlister asked about the $33 million to $40 million investments in
offsite conveyance of the stormwater. Mr. Ulma said how to address the
issue would have to be figured out over the long term in the capital
planning. Mayor
McAlister asked if it can be done in parts over time or if it has to
happen all at once. Mr. Ulma responded that it would have to be phased in
with project links so that it would average out. He said that the onsite
BMPs assume that the private development community would pay for them. He
said that the $33 million is the conveyance for pipes after the treatment
facility and that costs of maintaining and taking care of conveyance and
stormwater systems already exist. Ms. Brewer added that the study assumed
replacement of all pipes. Mr.
Coleman said it depends on how much of the total amount is the
responsibility of public and what amount is the responsibility of the
developer. He said that the Town requires an upgrade of water and sewer
lines for new development and part of the replacement cost may be
portioned to the development. He said it will be dependent upon how, when,
and where the downtown develops, and the Town’s ability to develop an
infrastructure plan in phases to meet development costs. Mr. Coleman said
that part of the Capital Improvement Plan (CIP) planning process is to
look at infrastructure needs in the downtown and identify particular
projects that can be done in phases to support development downtown. He
said that staff is looking at the overarching policy for stormwater issues
and once direction is given staff will begin working on the details of
implementing those plans. Mr.
Roseland asked about conveyance costs to alleviate current problems in the
TCAP. Ms. Brewer responded that The Tetra Tech study only looked at the
future development in the TCAP but that they or staff could do further
research. She said that there is a peak requirement in the most recent
regulations from the state Neuse Nitrogen Rule and that next year the
state will address the total volume control. Mr.
Roseland stated that he would like a holistic plan to do everything in the
Town Center Area, including fixing the current problems. Ms. Brewer said
that build out would mitigate the existing problems to a large degree;
however, it is going to be phased and will take over a decade. Mr.
Ulma said that the town is not set to deal with shared facilities under
the current regulations and staff needs to continue to address the
stormwater issues on a site by site basis with a movement towards looking
at the ordinances and creating mechanisms to allow for a sharing of
facilities. Ms. Brewer added that shared facilities may not be feasible
for all of the sites due to the cost for high density sites. Mayor
Pro Tem Smith asked if perhaps an unrealistic mix of uses was created with
the TCAP. Mr. Ulma responded that the zoning in those areas already
existed and they could have developed to the levels of imperviousness
anyway. Mr.
Roseland said he would like to receive data comparing the zoning before
the TCAP with the TCAP. Mr. Ulma said that staff will do a comparison of
the zoning that existed in the downtown before the TCAP and what the
zoning is today. He said the area was originally zoned just for commercial
or office and that the zoning and development in the core conceivably
could have happened before the development of the TCAP. He said that the
plan goes to more of a mixed use mode rather than single use. He said the
only difference is the expected uses within those buildings. Mrs.
Robinson said that staff should start thinking about a signature
characteristic for the downtown area, which includes looking at shared
facilities, examples of amenity to the appearance of the Town, and how to
encourage developments to gravitate towards shared facilities. Mr. Ulma
said that they are already anticipating this kind of direction in a
current development proposal. He said staff will need to determine how to
make the public/private work. Mayor
Pro Tem Smith asked if requiring shared facilities could be done through
incentives. Mr. Ulma said it could be done by different means, including
ordinance amendments. He said that staff would have to develop a mechanism
to identify and work with people on the BMPs and the mechanics. Mr.
Roseland suggested assisting with infrastructure costs and targeting
certain areas. He said we need to fix the existing problems and invest in
an infrastructure to support the redevelopment. Mr.
Joyce asked whether the pond in the Westbrook trailer park is a
site-specific pond. Ms. Pearce said it was not designed for storm water. Mr.
Joyce asked what BMPs are being used now. Ms. Brewer said the BMPs are
driven by the peak for the one year storm with 24 hour duration, and it is
the same for volume control. Mr.
Joyce asked if calculation for total volume with ponds can be deep as the
Town would want. Ms. Brewer responded no. Ms. Pearce said that staff
looked at building three regional ponds but that the EPA does not allow
ponds in streams. She said if ponds are built they have to be put where
there is no stream flowing into them. She said that you have to find a
place for the facility and then add the water and it becomes extremely
expensive to do that. Ms. Brewer added that new regulations do not allow
for retooling a pond for water quality or increasing the volume of an
existing pond. Mr.
Smith asked about regulations for circumstances where there is a
compelling reason to improve the environment. Ms. Brewer said there is an
option for exceptional cases. Ms.
Dorrel said that Council needs information about the downsides, challenges
and implications to the staffs’ conclusions. Mrs.
Robinson said information needs to be provided for clearing up existing
storm water issues and council needs to be made aware of any other
components to be cleared up before going forward. Mr.
Roseland said that the TCAP plan should be modified to respect the Swift
Creek agreement already made with neighboring communities. He asked for
information regarding how that will affect the vision of the TCAP. Ms.
Brewer said that it would not have a huge affect on the town center vision
because there are only about 25 acres in the Swift Creek portion of the
TCAP that need to go above the 70 percent and that is due to retention of
the low density. Mr.
Roseland asked who writes the check for the buy down option. Ms. Pearce
said that the developer writes the check to the state and they look for
restoration opportunities affecting the Swift Creek Area. Mayor
McAlister asked if council need to come up with a solution. Mr. Ulma said
that staff will take a report through committee for council presenting the
results and suggestions for potential ordinance changes, mechanisms or
funding, and recommendations for pursuing a balance for the environmental
requirements as well as achieving the vision for the TCAP. Ms.
Dorrel said that implications of the buy down need to also be included. Mayor
Pro Tem Smith asked for more information on the regional pond and
realistic goals. Mr.
Roseland said that a study needs to be done to fix the existing problems
in the Town Center Area. Mayor
McAlister directed staff to provide actions items to council. Mr.
Ulma said that staff will provide through committee a strategic action
plan for outcome of the analysis, including a summary, outline and
specific action items and recommendations. Mayor
McAlister adjourned the work session at 6:23 p.m.
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