Group_2 Vegetation-PondsAssessment of
Golden Valley’s
Vegetation
Management Plan
on Natural and
Constructed Storm
Water Ponds
ESPM 4041W Problem Solving for Environmental Change
Report 2/7 Prepared for:
The City of Golden Valley
Prepared by:
Nate Glocke—Project Leader
Meagan Welke—Project Leader
Sam Kreibich—Project Group Liaison
Trevor Christensen—Project Group Liaison
Renee Barker
December 10, 2012
Table of Contents
List of Figures...........................................................................................ii
List of Tables............................................................................................ii
Acknowledgments....................................................................................iii
Executive Summary.................................................................................iv
Introduction................................................................................................1
Vegetative Management in Golden Valley..........................................2
Nonnative Vegetation..........................................................................3
Vision/Current Strategy.......................................................................4
Group Profile.......................................................................................5
Goals and Objectives...........................................................................6
Methods.....................................................................................................6
Site Description....................................................................................7
Pond Classificaiton—Degree of Invasion (DI)....................................9
Development of Protocol...................................................................10
Findings...................................................................................................13
Ponds of Concern...............................................................................13
Public Perception...............................................................................16
Maintenance Agreement....................................................................16
Recommendations....................................................................................17
Conclusion...............................................................................................19
References................................................................................................19
Appendices
Appendix A: Vegetative Species Common to Minnesota
Appendix B: Degree of Invasion Field Sheets
Appendix C: Observed Species List
Appendix D: Map of City Subdivisions for Maintenance Inspections
Appendix E: General Maintenance Agreement
Appendix F: Maintenance Agreement Reminder Letter
Appendix G: Invasive Plant Guide
Appendix H: Interview Questions
Appendix I: Grant Information
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List of Figures
Figure 1: Golden Valley sampling locations........................................................8
Figure 2: An example of how sample sites were chosen: each
measurement location (indicated by a red dot) was located at one
of four azimuths (0°, 90°, 180°, 270°) and represented measurements
at the North, East, South, and West points of each pond............................11
Figure 3: The City of Golden Valley pond risk assessment...............................14
List of Tables
Table 1: Pond locations........................................................................................7
Table 2: Proximity risk assessment criteria.........................................................9
Table 3: Nonnative percentage criteria..............................................................12
Table 4: Risk assessment criteria for Golden Valley stormwater ponds............12
Table 5: Number/color assignment criteria........................................................12
Table 6: Golden Valley pond assessment..........................................................15
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Acknowledgments
We would like to extend our gratitude to the City of Golden Valley staff, who
welcomed us into their city and set aside considerable time in order to ensure that this
project was a success. By educating us about the history of Golden Valley as well as
its current state, they provided us with an in-depth understanding of the impact our
project would have on the city. Additionally, a project of this caliber would not have
been successful without the support of the citizens of Golden Valley as well as the
countless individuals who helped us along the way.
For their unmatched sincerity and generosity in supporting our cause, we would like
to candidly thank the following individuals:
Kent Johnson- Water Quality Manager-Met Council Environmental Services
Judy Sventek- Surface Water Manager-Met Council Environmental Services
Eric Eckman- City of Golden Valley Public Works Specialist
Andrew Erickson- St. Anthony Falls Laboratory Research Fellow
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Executive Summary
In order to address their growing concerns of Natural Resource Management, the City
of Golden Valley entered a cooperative analysis and assessment with the University
of Minnesota Environmental Science, Policy, and Management (ESPM) program.
The cities’ goal was for university students to incorporate innovative ideas and
strategies into their current natural resource plan. The University ESPM program’s
vision was:
"To create a proactive, cohesive, and flexible natural resource plan that supports
community engagement and advances the role of Golden Valley as a leader in
environmental management."
As part of that plan, the following report specifically focuses on a vegetative
management plan for stormwater ponds for the community of Golden Valley,
Minnesota. This plan will serve as a reference for the community and Natural
Resource department of the city as it strives for vegetative and environmental
stability and management in years to come. The primary objectives of this report
focused on the following items:
1.Creating an inventory of nuisance vegetation around stormwater ponds
2.Identifying best management practices that could be used to reduce vegetative
management requirements
3.Creating a reminder letter and educational sheet for businesses of their
responsibilities of vegetative management around their ponds
4.Designing an inspection and enforcement plan that will ensure vegetative
management requirements are being met by pond owners
5.Identifying grant and “free-labor” opportunities for vegetative buffers and for
employing inspectors to enforce Maintenance agreements
The findings in this report outlined nuisance vegetation around 25 ponds, a vegetative
management inspection plan, grant opportunities for implementation strategies, and
key plantings for stormwater ponds. The hope is that report will offer an effective,
adaptable management and inspection plan that could be implemented within the City
of Golden Valley.
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Introduction
Nestled on the outskirts of two major metropolitan cities, Golden Valley is a haven
for those not suited for inner city living. Despite being located less than five miles
from the urban areas of Minneapolis, Golden Valley is home to some of the most
beautiful natural and recreational areas that the metropolitan area has to offer. In
addition to having more than 30 parks and nature areas, Golden Valley contains
nearly 300 lakes, wetlands, and stormwater pond areas. These bodies of water
contribute to the overall health of surrounding rivers and streams and provide several
additional environmental services to the community including an improved aesthetic
appeal. The city is diligent in managing its water resources and has adopted several
programs and guidelines to ensure their preservation. Though members of the Golden
Valley community take great pride in these natural areas, recent years have worsened
the state of many wetlands and natural stormwater ponds throughout the Midwest via
the invasion of aggressive and exotic vegetative species.
The city is a 10.5 square mile area, with 28% of this being natural areas including
parks, nature preserves, and natural water bodies (Metropolitan council 2012). The
remainder consists of residential, industrial, and commercial areas as well as major
highways. It is an inner suburb, with Minneapolis bordering on the east and other
suburb communities bordering all other sides. The climate is temperate, with
generally cold winters and mild summers. Yearly precipitation ranges between 20-34
inches. Vegetation native to the Golden Valley area consists of many prairie grasses,
flowers, and herbs, including milkweed, goldenrod, ragweed, and mullein.
As people are naturally drawn to water-rich areas, the abundance of naturally
occurring water bodies in Golden Valley makes it a highly sought-after place to live.
However, development has had a major impact on the condition of both natural and
constructed bodies of water. As the amount of impervious surface in the community
increases, there is an increased amount of stormwater that must be drained to these
stormwater ponds. During a precipitation event, rain that lands on impervious surface
(i.e., roads, sidewalks, rooftops) must drain into the stormwater system. As this water
flows across the land, it picks up pollutants and transports them directly to the nearest
water body. Major sources of pollutants include items such as sediments, metals, and
spilled petroleum products (oil and gasoline). Additionally, runoff from residential
lawns and gardens contains fertilizers, pesticides and organic debris, such as grass
clippings and animal waste that can have significant impacts on water quality.
In addition to cleaning the water coming from both residential and commercial areas,
natural and constructed wetland ponds also provide flood protection to the
community and preserve the natural aesthetic of the water body. These benefits
however, are contingent upon the ability of the city and the citizens to maintain and
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manage these ponds in such a way that allows them to function most sustainably and
efficiently.
Golden Valley’s comprehensive plan is a public document that describes how the
community would like to develop in a given amount of time and the actions needed to
accomplish said goals. The plan is also intended to describe the relationships between
the community and the broader metropolitan area in terms of goals for improvement.
(Metropolitan Council, 2012). Golden Valley’s comprehensive plan is divided into
several sections including transportation, surface water, sanitary sewers, and water
supply. Each of these sections deals with particular issues that the community faces
and seeks out ways to improve them. In recent years Golden Valley has noticed
recurring issues with invasive plant species establishing within the community,
specifically around stormwater ponds. To combat these nonnative species, a
vegetative management plan is proposed in this report that will help this community
restore its native vegetation.
As mentioned earlier, there are many natural and constructed ponds and wetlands
within the city limits of Golden Valley. Of these, more than two-thirds are natural
ponds and tend to be evenly distributed throughout the community. The constructed
ponds are typically located near areas that have a significant pollutant source or are
prone to flooding. In general, constructed ponds are located near other ponds to
improve their pollutant removing efficiency or near highly traveled roadways, such as
Highway 55. The focus of this project is vegetative management pertaining to both
natural and constructed stormwater ponds.
Vegetative Management in Golden Valley
In 2003, the City of Golden Valley performed a Natural Resource Inventory (NRI)
that completed a Minnesota Land Cover Classification Survey (MLCSS) to analyze
the current state of the vegetation within numerous parks throughout the city. An
intensive inventory was taken, specifically noting nuisance vegetation, such as Purple
Loosestrife (Lythrum salicaria) and Common Buckthorn (Rhamnus cathartica). One
of the main goals of the NRI was to gather information about the natural resources
and the resource management demands throughout the city. Their hope was that this
inventory could be used in future vegetative management strategies. Although the
NRI is slightly outdated, the need for vegetative management is still prevalent. While
all of this information is beneficial, it could be more beneficial in coincidence with a
vegetative management plan.
Vegetation around stormwater ponds is an emerging problem of concern due to the
intensive management that they may require. Currently, there are a number of issues
associated with the management of stormwater ponds, particularly about who is
responsible for maintenance and inspection. The City of Golden Valley along with
the Basset Creek Watershed District require maintenance agreements for private pond
2
owners, however these agreements are rarely enforced due to lack of resources. In
order to keep these ponds working efficiently it is necessary to maintain the
vegetation surrounding these ponds on an annual basis. The maintenance agreements
set forth by the city and the watershed district requires that during the first two years
following pond construction the basins should be weeded monthly. After the first two
growing seasons, weeding is recommended 2 to 3 times within the growing season.
The actual maintenance agreement can be found in Appendix E.
Weeds and invasive species can be very difficult to contain. As earlier stated in the
NRI of 2003, it was found that a number of ponds are infested with invasive species,
such as purple loosestrife and buckthorn. While these invasive weeds are a nuisance,
noxious weeds, such as thistles or crown vetch, can be just as troubling. Stormwater
ponds are more susceptible to weed invasion due to the constant flow of water in and
out of them, and can act as a breeding ground for nuisance vegetation. Noxious weeds
and invasive species also can overcrowd some native vegetation surrounding these
ponds and can be extremely difficult and time consuming to control. Most people
who are responsible for stormwater ponds do not want to take the effort to effectively
manage and weed the vegetation surrounding these ponds due to the amount of work
required. While the work is relatively simple, it can be time consuming, which leads
to people to forget about the importance of managing their vegetation. Additionally,
there is no enforcement that forces pond owners to keep up with their vegetation or
they do not understand the difference between native and nonnative species.
Nonnative Vegetation
Nonnative plant invasion is a chronic issue throughout much of the continental
United States. A simple way to understand plant invasion is to consider the local
vegetation and climate here in Minnesota. The typical growing season in Minnesota
is from April to August, in which time both native and nonnative plants compete for
resources that are essential for their own survival like sunlight, water, and nutrients.
An invasive species is defined as “an alien species whose introduction does or is
likely to cause economic or environmental harm” (NISC, 2006). In simpler terms, an
invasive species is any species that out-competes native species for resources and
grows beyond their planted boundaries. Noxious species are specific types of invasive
species that can be harmful to human or animal health, the environment, public roads,
crops, livestock or other property. Aggressive species can be either exotic or native
species. What makes these species aggressive is their ability to spread quickly,
displace native vegetation, and their ability to tolerate non-ideal environmental
conditions. (EPA, 2001). A list of Minnesota’s local Native, Invasive, Noxious and
aggressive species can be found in Appendix A. Many native plant species, especially
those associated with wetlands or pond areas, serve as natural filtration devices by
removing harmful chemicals and sediments from stormwater, and thus are vital to the
health and functionality of stormwater ponds.
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Proximity to already invaded areas is a high indicator of whether an adjacent area
will soon be colonized by invasive species. Because of the dominant nature of most
invasive species, patches can spread quite quickly. According to Auld et al., the
spreading of weeds is a function of the dispersal pattern of propogules, reproductive
capacity of individuals, population size, germination/establishment, microsite
limitations, and climatic/edaphic limitations (1989). Common characteristics of
invasive species include high reproductive capacity and high ability to adapt or thrive
in changing conditions. The distance from managed or unmanaged areas is also a
factor for determining if invasive species will spread for different reasons. If a pond
is nearby highly managed areas, there could be a lower risk of spread due to public
perception that a managed area adjacent to an unmanaged area is unsightly.
Though it may seem that species abundance may have the greatest bearing on
management of nonnative species, species richness also plays a large role in
determining the future of invasion. For example, communities with high nonnative
species richness contain a large percentage of species that may become invasive in
the future when environmental or resource conditions are altered. To illustrate more
clearly the impacts of species richness and abundance, take for example one
community with low nonnative species richness and high nonnative species
abundance and another community with high nonnative species richness and low
nonnative species abundance. Whereas the former community would be indicative of
a few individual species that have the ability to take over an area the latter would
suggest that there is a proportion of nonnative species richness that once surpassed,
would lead to an explosion of nonnative species, thus reducing the number of native
species (Guo, 2007).
Vision/Current Strategy
The City of Golden Valley is seeking an inspection program which assesses the state
of the vegetation at these ponds. Although the city does currently maintain and
inspect a number of ponds, the remaining ponds often go unmanaged. The quantity of
remaining ponds throughout the city makes it extremely difficult to inspect and
maintain the total amount. In order for vegetative management to be efficient it is
necessary to perform an annual vegetation inspection. If ponds are inspected once a
year they become much easier to maintain. The earlier that nuisance vegetation is
identified, the easier it becomes to control. If left without inspection, nuisance
vegetation may take over the inlets and outlets of a pond, thereby damaging the
integrity of the pond due to the clogging of the flow of water. If preventative
monitoring can be performed regularly, intensive management can be eliminated
before it actually starts to occur. As the City of Golden Valley moves into the future,
it will need to follow the examples of surrounding cities and develop a way to
manage to their stormwater features. Because vegetation is an important element of
stormwater ponds, the City of Golden Valley needs to develop a plan to manage the
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vegetation of these ponds. Golden Valley’s vision on stormwater outlines the current
outlook of the expectations of stormwater ponds.
The City of Golden Valley takes great pride in their abundant surface water
resources. Stormwater ponds contribute to keeping larger bodies of water, such as
Basset Creek, clean and functioning. Even with the great focus already existing for
maintaining high water quality, there are still many challenges to managing
stormwater ponds. The current plan in place for stormwater management is the
Surface Water Management Plan (SWMP), which highlights plans for
implementation, policies, goals, and issues.
One goal related to the water quality of stormwater is to “maintain the nutrient and
sediment removal efficiency of several key stormwater ponds throughout the city,
thereby improving the water quality of the receiving waters.” The policies in place
largely defer to the requirements of the Bassett Creek Watershed Management
Commission in addition to staying updated on Best Management Practices (BMP)
and technology for ponds. Also, the city plans to continue to “require maintenance
agreements for private water quality facilities and develop procedures and resources
to enforce these agreements” in order to address the management of ponds outside of
public areas.
A second goal is to “improve the pollutant removal effectiveness of stormwater
ponds within the city.” Funding is needed for this project in order to continue
management of ponds, including sediment control and BMP initiatives.
A third goal is to “improve erosion and sediment control through aesthetically
pleasing and environmentally friendly means.” This goal recognizes the aesthetic
value that the city and its residents hold for their natural areas. In order to accomplish
this goal, native vegetation buffers need to be developed on both city and noncity
property, which will involve support and encouragement from the city to these
private areas. Also included in this goal is consideration of how future ponds that are
aesthetically pleasing will be developed in new locations when appropriate.
Group Profile
The team developing this vegetation management strategy for the City of Golden
Valley is composed of six University of Minnesota Seniors with diverse backgrounds
in environmental science, policy work, and natural resource management. Each team
member brings their own strengths to this policy plan. Our unique skill set ranges
from experience in stormwater pond monitoring to policy development and
implementation. Our backgrounds bring us together as a dynamic team, with a
common vision for the future of vegetation management surrounding Golden Valley's
many stormwater ponds.
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The overall vision of our team is to provide the City of Golden Valley with an
exemplary stormwater pond vegetation management plan. Part of this vision is to
make that management plan realistic and implementable, and adaptable. Being
realistic includes considering its cost in dollars, man hours, and political
acceptability. Being implementable means the plan, once completed, is ready to be
immediately accepted by the city, can use the city's current resources and can be
employed as active policy in the near future. The adaptability of this plan will involve
it being created with the ability to evolve and address unforeseen challenges that the
city may face in the future.
Goals and Objectives
1.Recommend best management practices that minimize the need of vegetative
management around inlets.
2.Determine the best approach for reminding and enforcing Maintenance
Agreement holders of their responsibilities for vegetative management in their
ponds
3.Collaborate with other groups to create a policy that outlines the maintenance
requirements of stormwater ponds
4.Obtain a list of ponds and divide the city into subdivisions based on those ponds
for annual inspections. Create an enforcement and management schedule for the
growing season
5.Assess a representative number of key ponds and create an area map detailing
their levels of risk based on the classifications of proximity to managed areas,
proximity to already invaded areas, and degree of invasiveness
6.Create a management plan if inspection results require further action based on the
level of risk associated with a given pond. To supplement said management plan,
we will include in our recommendations a detailed protocol as well as a calendar
that may be used as a guideline in coordination of inspection and management
efforts.
Methods
The 10.5 square mile area of Golden Valley is primarily made up of residential
homes. This, along with commercial and industrial use area, is drained into a mere
3% of the area, which are open water bodies. Appendix C shows the location of these
water bodies, along with distinguishing constructed stormwater ponds, as natural and
wetland ponds. Roughly 2/3 of the ponds are located in the southern half of Golden
Valley, with the other third lying in the north. These ponds are used for stormwater
storage, treatment of nutrients and potentially harmful chemicals, and sediment
control. In order for these ponds to function correctly, surrounding vegetation needs
to be functioning properly.
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As part of developing recommendations, brief interviews were conducted with the
City's Public Works officials on October 9, 2012. The goal from this was to better
shape the proposal to exactly meet the city's needs. The interview discussion took
place at the City Council Chambers in Golden Valley, and consisted of three
representatives from our group; two for note-taking and one to act as a spokesperson
and voice questions and comments about the progress that is being made. In addition
to writing notes, the interview was recorded via smart phone for reference.
Site Description
This study focused on the vegetation surrounding 25 different ponds (Figure 1) that
are a representative sample of all the types of ponds in Golden Valley. Each pond was
categorized based on the surrounding vegetation, proximity to managed areas, and
proximity to invaded areas which is described below. Native vegetation is extremely
important for stormwater ponds, because of the diverse habitat it offers. This
diversity allows for stable ecosystems when dealing with pests, diseases, and climate
change. In order for stormwater ponds to function properly, diverse vegetation need
to filter out pollutants and sediment before the water can reach major waterways.
This study used the data collected from these 25 ponds to develop the vegetation
management plan for the city of Golden Valley.
Table 1. Pond locations.
Pond Name Location
Ardmore South Pond Glenwood Ave./Ardmore Dr.
Briarwood Nature Area Pond*Scott Ave. N./Hampton Rd.
Cavalry Co-op Pond*Rhode Island Rd. (North of Cavalry Center Coop)
Dahlberg Pond*Meadow Ln N. (West of Humane Society)
East Ring Pond Louisiana Ave S./Laurel Ave.
General Mills Campus*Hwy. 169/Betty Crocker Dr.
General Mills Nature Preserve Between Betty Crocker Dr. and Hwy. 55
Georgia Pond Glenwood Ave./Georgia Ave. N.
Golden Meadow Pond*Winnetka Ave./23rd Ave. N.
Golden Ridge Pond*Naper St./Gettysburg Ct.
Golden Valley Rd/Boone Ave Pond*Golden Valley Rd/Boone Ave.
Holiday Inn Pond*Golden Hills Rd.
KFC Pond*6th Ave. N. (Behind KFC)
Kings Valley Rd. Pond*US 169 Frontage Rd./Kings Valley Rd.
Knoll Street Pond*County Rd. 102/Knoll St.
Medicine Lake Road Pond*Medicine Lake Rd./ Nevada Ave.
Medley Park Pond*Mendelssohn Ln
South Tyrol Pond Tyrol Trail/Alpine Pass
Spirit of Hope Church Pond*Rhode Island Ave. N./Harold Ave.
Strawberry Pond Strawberry Ln./Westwood Dr.
Toledo - Angelo Pond*Toledo Ave. N/Winsdale St. N.
Tyrol Terrace Pond N. Tyrol Trail/Meadon Ln. S.
West Ring Pond Louisiana Ave S./Laurel Ave.
Wirth Pond*Meadow Ln. N./Woodstock Ave.
Xenia Avenue Pond*Laurel Ave./Xenia Ave. S.
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Figure 1. Golden Valley sampling locations.
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Pond Classification—Degree of Invasion (DI)
In order to collect data on the current state of Golden Valley's stormwater ponds,
producing an inventory was necessary. Because of the large extent of stormwater
ponds in the city, the approach taken was to survey a representative sample of ponds
and classify them according to different typologies. These typologies reflect how
high of a threat invasive species are for that buffer area. In order to determine this
threat, three main classifications were used: proximity to managed areas, proximity to
already invaded areas, and degree of invasiveness. From this information a sense of
the current conditions was analyzed to determine our recommendations for best
management practices and a vegetation monitoring plans. In the analysis of
stormwater pond vegetation, noxious and aggressive species were also taken into
consideration as they too can out-compete native species for resources.
A literature analysis regarding proximity of adjacent areas to already invaded areas,
the following ranges were determined for the risk assessment: a pond 100+ meters
away from an invaded area represents a pond having a low risk of invasion; 99 to 51
meters represents a moderate risk of invasion; 50 to 21 meters, a high risk of
invasion; 20 to 0 meters, a very high risk of invasion. Additionally, the ranges for risk
due to distance from managed areas are: 0 to 20 meters, low risk of invasion; 20 to
50 meters, moderate risk of invasion; 51 to 99 meters, high risk of invasion; 100+
meters, very high risk of invasion. (Reference Table 2 below for a compilation of risk
criteria). In the analysis, a managed area ranges from constructed buildings, such as a
neighborhood or business, to high-use landscapes such as parks. If the nearest
managed landscape is farther away, there is a lesser chance that the unmanaged patch
is noticed and therefore not brought to the attention of city or private managers.
Table 2. Proximity risk assessment criteria.
Proximity to Invaded Areas Proximity to Managed Areas Assigned Values/Colors
100+ Meters 0-20 Meters 1/Green
99-51 Meters 20-50 Meters 2/Yellow
50-21 Meters 51-99 Meters 3/Orange
20-0 Meters 100+ Meters 4/Red
The method that was used to classify ponds as “very high risk”, “high risk”,
“intermediate risk”, or “low risk” was the Degree of Invasion (DI) method. This
method combines the measures from proximity to managed areas and proximity to
invaded areas with an additional measure of DI to give the best estimate of invaded
land percentage. DI is defined as “the susceptibility of an environment to the
colonization and establishment of individuals from species not currently part of the
resident community” (Davis, 2005). Put another way, DI measures the likelihood of a
nonnative species moving into a new community and establishing itself amongst
locally adapted species. Past research has been done using metrics such as survival,
density, or biomass of exotic species to determine degree of invasion. These methods
9
have produced inconsistent results that do not allow for comparison amongst
communities with similar problems. It is in this area that the DI method excels. The
DI method consists of two separate measurements: nonnative proportion of total
species richness and nonnative proportion of total species abundance. The key word
here is proportion; by taking proportional measurements, (expressing nonnative
richness and abundance as a fraction of total species richness and abundance) this
measurement allows for comparisons between sample points and even across entire
regions (Guo, 2007).
In taking the DI measurement, it is essential that both species richness and abundance
measurements are made. Here species richness is defined as the number of different
species within a specified area and species abundance as the number of individuals of
a specific species in a specified area. The reasoning behind the dual measurement
method is the fact that neither of the two measurements alone is a good measure of
degree of invasion. Species richness alone is an inadequate measurement of degree of
invasion because not all invasive species invade areas to the same degree. For
example, an area may have a high percentage of nonnative species (high nonnative
species richness) but may not dominate the area in terms of land cover (low
nonnative species abundance). Likewise, species abundance alone is also an
ineffective measurement of degree of invasion because a high abundance of
nonnative species does not necessarily mean that the area is overwhelmingly invaded.
For example, if an area’s dominant species is a nonnative plant, measures could be
taken to reduce the population of that plant and restore the proportion of native
plants. When paired however, these two measurements provide the best overall
picture of the degree of invasion of an area.
Development of Protocol
The general protocol by which the degree of invasion was measured is as follows:
After arriving at the desired pond, the name and location of the pond was recorded to
ensure the data could be associated to that specific pond. All information was
recorded on the field sheet found in Appendix B. The water body and buffer areas
were also recorded as determined by GIS measurements. Once this preliminary data
had been recorded, four locations were chosen around the periphery of the pond as
determined by the azimuths: 0° (North), 90° (East), 180° (South), and 270° (West).
To find these four locations GIS was used to draw an imaginary rectangle around the
outermost edges of the pond (Figure 1). The length of the rectangle’s sides
determined the halfway point of both the length and width of the pond, thereby giving
the respective North/South and East/West locations.
At each of the four sampling locations around the pond, collection of both nonnative
species richness and species abundance took place. Two meter sticks were placed on
the ground perpendicular to each other to give a reproducible area (plot) from which
to obtain the data. By consistently using the same sized sample area at each sampling
location, the effects of different sample size areas as well as resource availability
10
were able to be ruled out. Within this square meter plot both species richness and
species abundance data was collected.
Figure 2. An example of how sample sites were chosen: each measurement location (indicated by a
red dot) was located at one of four azimuths (0°, 90°, 180°, 270°) and represented measurements at the
North, East, South, and West points of each pond.
For collecting species richness, the number of different species was counted, both
native and nonnative, within the plot were and the number of nonnative species as a
proportion of the total number of species was recorded within the plot. The same
method was then used to collect species abundance data with the difference being that
what was counted was the number of native and nonnative individuals within the plot
and the number of nonnative individuals to the total number of individuals within the
plot was expressed.
Lastly, for each sampling location it was noted what species were present within the
plot. More exhaustively, notes were made of any additional species that were present
in the pond buffer that were not found in any of the four plots. The reasoning behind
taking a comprehensive inventory is to establish what species are present at any given
pond. This information determined the dominant species and which species, if any,
could be expected to be seen progressing its invasion. As the last step in the data
collection process, the proportions for both species richness and abundance were
averaged to give us one averaged value of species richness and another averaged
value of species abundance.
After all of the field data had been collected, an analysis was conducted to determine
the individual pond’s level of risk. Assigned values were given to a given pond that
corresponded to the percentage of nonnative species within the vegetative buffer. The
general classification system that was used to determine a pond’s risk is as follows:
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Table 3. Nonnative percentage criteria.
Average nonnative species abundance
(%area)Assigned values/colors
0-30 1/Green
31-50 2/Yellow
51-75 3/Orange
76-100 4/Red
Combining the risk assessment criteria from Tables 1 and 2 we have:
Table 4. Risk assessment criteria for Golden Valley stormwater ponds.
Average nonnative
species abundance
(% area)
Proximity to invaded
areas
Proximity to managed
areas
Assigned
values/colors
0-30%100+ Meters 0-20 Meters 1/Green
31-50%99-51 Meters 21-50 Meters 2/Yellow
51-75%50-21 Meters 51-99 Meters 3/Orange
76-100%0-20 Meters 100+ Meters 4/Red
Once the data had been collected and values for average species richness and
abundance were calculated, the classification system was implemented. To assign any
given pond a number and corresponding color, the averaged species nonnative
abundance value was averaged with the assigned numbers from proximity to
managed areas as well as the number from proximity to invaded areas. The general
equation
Degree of Invasion (DI) =
Averaged species abundance + Proximity to managed areas + Proximity to invaded areas
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was used to calculate the degree of invasion. Because this value was typically a
decimal between 1 and 4, further criteria listed in Table 4 was used to determine the
final rating and color assignment for each pond.
Table 5. Number/color assignment criteria.
Degree of invasion value Assigned number Assigned buffer color
DI < 1.5 1 Green
1.5 DI 2.5 2 Yellow
2.5 < DI <= 3.5 3 Orange
3.5 < DI 4 Red
12
Findings
As part of the preparatory work for this experiment, research and interviews regarding
the state of ponds in Golden Valley were conducted. It was observed that several of
the representatives from Golden Valley were concerned by the amount of vegetative
invasion that was occurring around ponds throughout the city. In an attempt to create a
management plan for Golden Valley, it was decided that 25 specific ponds, both
natural and constructed, would be subjected to the DI measurement. Our goal in
determining which ponds would be measured was to select a set of ponds that would
be representative of all ponds within Golden Valley. By doing so, a management plan,
created based on these 25 ponds could serve as a viable management plan for all of the
ponds in Golden Valley. Additionally, because both natural and constructed ponds
were measured, any notable differences between the two will result in the creation of
two separate management plans.
Ponds of Concern
As seen in Figure 1, ponds were chosen throughout the city. The majority of these
ponds were regarded by Golden Valley representatives as ponds of concern. More
specifically, these ponds were viewed as either currently invaded or, if not yet
invaded, at risk of being invaded from surrounding areas.
The results from the experimental data are shown in Table 5. This table is a
compilation of the data that we collected from each of the ponds and also includes
each pond’s overall ranking and color code as determined from equation 1 and Table
4.
Of the 25 ponds that were measured for DI, 17 were constructed, meaning the
remaining 8 ponds were naturally occurring. Of the 25 total ponds, 3 were considered
“low risk”, 6 “moderate risk”, 8 “high risk”, and the remaining 8 were considered
“very high risk”. The data also reveals that 7 of the 8 ponds considered to be at low or
moderate risk of invasion were constructed ponds. In fact, there was only one natural
pond (General Mills Nature Preserve) that obtained moderate risk status and none that
achieved low risk status.
13
Figure 3. The City of Golden Valley pond risk assessment.
In carrying out the DI measurements, it was observed that Common Buckthorn
(Rhamnus cathartica) and Reed Canary Grass (Phalaris arundinacea) were by far the
most invasive vegetation species throughout Golden Valley. Though some ponds were
buckthorn free, nearly all ponds were in close proximity to land that was invaded with
buckthorn. Buckthorn has been an issue in Golden Valley since before 2003 when the
city published a vegetation inventory in which they listed and mapped areas of
nuisance vegetation (City of Golden Valley, 2003). In the 2003 inventory, several
other nuisance species were mentioned as being problematic within the community;
the most prevalent of these being Purple Loosestrife (Lythrum salicaria), Reed Canary
Grass (Phalaris arundinacea), Crown Vetch (Securigera varia), and Spotted
Knapweed (Centaurea maculosa).
14
Pond name
Average nonnative
species abundance (% area)
Average nonnativespecies abundance
Proximity to invadedareas
Proximity to
managed lands
DI valueOverallHoliday Inn Pond*01111
1
General Mills Campus*111211.33
1
Knoll Street Pond*7.251121.33
1
Golden Ridge Pond*824112
2
Briarwood Nature Area*7.751242.33
2
Cavalry Co-op Pond*81422.33
2
Dahlberg Pond*543312.33
2
General Mills Nature Preserve41.52412.33
2
Xenia Avenue Pond*6.251332.33
2
Toledo - Angelo Pond*713142.66
3
Wirth Pond*964312.66
3
Medicine Lake Road Pond*91.54143
3
South Tyrol Pond83.754413
3
Tyrol Terrace Pond98.754413
3
Ardmore South Pond813433.33
3
East Ring Pond69.53343.33
3
Kings Valley Rd. Pond*99.254243.33
3
Golden Meadow Pond*73.253443.66
4
Golden Valley Rd/Boone Ave Pond*98.664433.66
4
KFC Pond*75.53443.66
4
West Ring Pond974343.66
4
Georgia Pond944444
4
Medley Park Pond*904444
4
Spirit of Hope Church Pond*854444
4
Strawberry Pond1004444
4
*Denotes a constructed pond.Table 6.
Golden Valley pond assessment.
As part of our measurement protocol, exhaustive vegetation inventories were taken at
each pond. In total, we counted 41 different invasive/aggressive species (Appendix C).
Our inventories show that the most common nuisance species were Common
Buckthorn and Reed Canary Grass. Because these two species are generally fast
spreading and are tolerant of non-ideal conditions, they have the ability to not only
out-compete native vegetation but other invasive/aggressive vegetation as well. This
being said, it is fortunate that there are only a few dominant invasive species. Though
these species spread quickly and are difficult to control, the amount of work that will
be required to control them is substantially lessened by the fact that they are the two
most prevalent species.
Public Perception
Public perception of ponds plays a large role in determining which ponds should be
restored and which ones should not. Public perception in turn is largely influenced by
how well informed citizens are. In addition to the data that was collected, we were
given information, by way of interview, that led us to believe that the citizens of
Golden Valley were not well informed about invasive species and the impacts of
nonnative vegetation on stormwater ponds. As a specific example of this, we were told
that many individuals considered the East and West Ring Ponds to be in good health
and were very proud of how aesthetically pleasing the ponds were. As it turns out,
these two ponds are nearly 70% and 97% invaded respectively (Table 5).
This example highlights the way in which Golden Valley citizens think about
vegetation; they are under the false impression that a green plant is a desirable plant.
As mentioned above, there were 41 different invasive/aggressive species observed at
the 25 pond locations. The ability to identify common invasive/aggressive species
plays a major role in the public’s misconception of what desirable plants are. It is our
belief that if individuals had the ability to identify common invasive species, their
perception of vegetative buffers would be altered and would therefore be more
supportive of restoration projects. At this time however, public perception of
stormwater pond aesthetics remains positive.
Maintenance Agreements
As mentioned above, the city Golden Valley along with the Basset Creek Watershed
District requires maintenance agreements for private pond owners (Personal
communication). These agreements specifically state,
“The Owner shall be solely responsible for the maintenance of the facility, and
shall bear all costs of such maintenance. If the Owner does not undertake the
necessary maintenance within thirty (30) days of notification by the City, the City
may contract such maintenance, but the costs reasonably incurred by the City for
16
contracting such maintenance shall be reimbursed to the City by the Owner”
(Appendix E).
Prior to data collection, several ponds were visited in order to narrow down our
criteria for choosing sampling locations. Through direct observation we were able to
determine that the vast majority of the privately owned ponds were not in good
condition. We were also told prior to beginning our project that enforcement of
maintenance agreements was limited due to finite resources. It occurred to us that the
poor condition of privately owned ponds could potentially be due to this lack of
enforcement and that some form of reminder may be needed to motivate private pond
owners to comply with their agreements.
Recommendations
As a result of all data analyses it was determined that the City of Golden Valley needs
to follow in the footsteps of its neighboring cities and incorporate a vegetative
management inspection plan that will combat the growing concerns of nuisance
vegetation around the city’s stormwater ponds. This inspection plan shall include
biannual inspections of individual city subdivisions. The subdivisions shall follow the
current inspections program set forth by the city for storm sewer inspections. The
intention was to use the current subdivisions already in place to make it more
adaptable for the city. Each year, the city should inspect all of the ponds with
maintenance agreement in one of the three subdivisions. They should perform two
inspections throughout the growing season; the first will determine the status of the
vegetation of the pond. Then the city shall issue a report to the pond owner indicating
the measures that the owner needs to take in order to be compliant with the regulations
set forth by the city. The second inspection should take place later in the growing
season and will ensure that the pond owners met the requirements as outlined in a
report. In order to be even more efficient, the inspector should also inspect the pond
for its functionality by ensuring that water is flowing into the pond and that
sedimentation and erosion are not occurring.
In order to accommodate an inspector the city should take advantage of its current
summer help or implement an internship for university students. Grants are available
for nuisance vegetation control and some classes offer a service-learning component
that uses volunteer students to accommodate environmental needs and services of
local businesses and organizations.
Once the city is split up into individual sections for pond assessment efficiency, it is
recommended that each pond is evaluated using the degree of degree of invasion
method mentioned above. By observing each pond for nonnative species richness,
species abundance, proximity to invaded areas, and proximity to managed lands a
value ranging from 1 to 4 can be backed out to determine how invaded or prone to
17
invasion a pond is. This method is again mentioned above in the “Methods” section.
Ponds that score a 1 have very little degree of invasion and therefore need to be
monitored for invasive plants, to ensure that they do not encroach on the pond. Ponds
that score a 2 to 3 or range from 25 to 75% comprised of invasive species should be
focused on removing any invasive plant species and reintroducing native plant species.
A number of different control options can be helpful in executing this removal
process. The removal of many plants can be done through wrenching, stump cutting,
and the use of herbicides. We recommend a combination of all three of these processes
in order to ensure complete eradication of invasives in these areas. However because
Golden Valley is dealing with a sensitive buffer zone, herbicides that are meant for
aquatic use, such as Rodeo, must be used to ensure the chemicals do not spread into
the pond itself. Using grants listed above should ensure the replanting of vegetation
around ponds. This process can also be outsourced to agencies such as Prairie
Restoration. In order to manage ponds with a score of 4, we felt that too much time
and resources would go into the area without seeing very drastic results over a short
time; unlike the previous scores. We recommend trying to limit the spread of invasives
out of the region through creating larger managed areas around it, in order to save
those areas and prevent the spread out of the area. By using the risk assessment to
determine which ponds, need to be monitored for invasive species, effective
management practices will be maximized due to the organization and focus on critical
areas.
Ideal plantings for stormwater management ponds vary according to location variables
such as soil, sunlight, and other species. They provide an ideal natural setting while
also accomplishing the goals of stormwater infiltration and buffering. In addition to
forbs, grasses, and flowering plants, trees and woody vegetation are also effective for
stormwater management. Trees are valuable for their ability to reduce water volume
and peak flow of runoff which in turn reduces flooding and erosion (Shaw 2003). For
an extensive list of native plantings for the state of Minnesota, including descriptions
of ideal range, water levels, tolerances, sensitivities, and wildlife use, please refer to
the latest volume of Plants for Storm Water Design: Species Selection for the Upper
Midwest by Daniel Shaw and Rusty Schmidt.
The group has also identified two grants that would assist the city of Golden Valley in
implementing the recommendations above. These grants are sponsored by Great
River Greening and the National Fish and Wildlife Foundation, if received these
grants could assist in putting these recommendations into action without city funds.
Information on these grants can be found in Appendix I.
18
Conclusion
Golden Valley is a community that places great pride in taking care of their natural
resources. They have an abundance of natural and constructed water bodies that add to
the value of their surroundings. In order to enhance this commitment to the
environmental and aesthetic value that their natural resources bring, Golden Valley
can further the extent of their responsibility by addressing the currently unmanaged
stormwater ponds throughout the city. The steps outlined in this report provide the
framework for taking on this large task.
References
The City of Golden Valley. 2003. Natural Resource Inventory.
Davis, M. A. 2005. Degree of invasion: the local mechanism driving community
assembly and species diversity. Ecography 28(5). Retrieved from:
http://onlinelibrary.wiley.com/doi/10.1111/j.2005.0906-7590.04205.x/pdf
Department of Natural Resources. n.d. Storm Water Basins - Using Natural
Landscaping for Water Quality and Esthetics. By JoAnn M. Gillespie and D. Litt.
n.d. University of Wisconsin - Extension, 2005. Web. 19 Sept. 2012. http://clean-
water.uwex.edu/.
Eckman, Eric. October 9, 2012 (Personal Communication)
Guo, Q. 2008. A two-part measure of degree of invasion for cross-community
comparisons. Conservation and Biology 22(3):666-672.
Metropolitan Council. 2012. Community Profile for Golden Valley. Retrieved
September 22, 2012 from
http://stats.metc.state.mn.us/profile/detail.aspx?c=02394924.
Minnesota Pollution Control Agency. n.d. Plants for Storm water Design: Species
Selection for the Upper Midwest. By Daniel Shaw and Rusty Schmidt. Ed. Sam
Brungardt. 2003. Print.
The National Invasive Species Council (NISC). 2006. Invasive Species Clarification
and Guidance White Paper. What is an Invasive Species? Retrieved from:
www.invasivespeciesinfo.gov/docs/council/isacdef.pdf
US Environmental Protection Agency (EPA). 2001. An Ecological Assessment of
Invasive and Aggressive Plant Species in Coastal Wetlands of the Laurentian
Great Lakes: A Combined Field-Based and Remote Sensing Approach. U.S. EPA
National Exposure Research Laboratory.
Yencha, A. 2004. Options for open space. SouthEast Fox River Partnership.
University of Wisconsin System. Accessed 23 Sept. 2012.
http://basineducation.uwex.edu/southeastfox/projects/openspace.htm.
19
20
Appendices
Appendix A: Vegetative Species Common to Minnesota
Genus Species Common Name
Canopy Trees (>10 m)
Acer saccharum Sugar maple
Betula papyrifera Paper-birch
Carya cordiformis Bitternut hickory
Fraxinus pennsylvanica Green ash
Fraxinus nigra Black ash
Ostrya virginiana Ironwood
Populus tremuloides Quaking aspen
Prunus serotina Black cherry
Quercus rubra Northern red oak
Quercus alba White oak
Quercus macrocarpa Bur oak
Tilia americana Basswood
Ulmus americana American elm
Ulmus thomasii Rock elm
Ulmus rubra Slippery elm
Understory Trees
Acer saccharum Sugar maple
Acer negundo Box elder
Betula papyrifera Paper-birch
Carpinus caroliniana Blue beech
Carya cordiformis Bitternut hickory
Celtis occidentalis Hackberry
Fraxinus pennsylvanica Green ash
Fraxinus nigra Black ash
Ostrya virginiana Ironwood
Populus grandidentata Big-toothed aspen
Populus tremuloides Quaking aspen
Prunus serotina Black cherry
Quercus rubra Northern red oak
Quercus macrocarpa Bur oak
Quercus alba White oak
Tilia americana Basswood
Ulmus rubra Slippery elm
Ulmus americana American elm
Ulmus thomasii Rock elm
21
Shrubs
Amelanchier cmx. Juneberry
Cornus alternifolia Pagoda dogwood
Cornus racemosa Gray dogwood
Corylus cornuta Beaked hazelnut
Corylus americana American hazelnut
Diervilla lonicera Bush honeysuckle
Dirca palustris Leatherwood
Lonicera dioica Wild Honeysuckle
Lonicera canadensis Fly honeysuckle
Prunus virginiana Chokecherry
Ribes cynosbati Prickly gooseberry
Ribes missouriense Missouri gooseberry
Sambucus racemosa Red-berried elder
Sambucus canadensis Common elder
Staphylea trifolia Bladdernut
Symphoricarpos cmx Snowberry
Viburnum rafinesquianum Downy arrow-wood
Viburnum lentago Nannyberry
Viburnum opulus High-bush cranberry
Zanthoxylum americanum Prickly ash
Low Shrubs
Rubus idaeus Red raspberry
Rubus cm1 Blackberry
Toxicodendron rydbergii Poison ivy
Vines
Celastrus scandens Climbing bittersweet
Clematis virginiana Virgin's bower
Lonicera prolifera Grape honeysuckle
Menispermum canadense Canada moonseed
Parthenocissus spp. Virginia creeper
Smilax hispida Green-briar
Vitis riparia Wild grape
Forbs
Actaea rubra Red baneberry
Allium tricoccum Wild leek
Allium tricoccum Burdick's leek
Amphicarpaea bracteata Hog-peanut
Anemone quinquefolia Wood-anemone
Anemone acutiloba Sharp-lobed hepatica
Anemone americana Round-lobed hepatica
Aplectrum hyemale Putty-root
Apocynum androsaemifolium Spreading dogbane
Aquilegia canadensis Columbine
Aralia nudicaulis Wild sarsaparilla
Aralia racemosa American spikenard
22
Arisaema triphyllum Jack-in-the-pulpit
Asarum canadense Wild ginger
Asclepias exaltata Poke milkweed
Aster cordifolius Heart-leaved aster
Aster macrophyllus Large-leaved aster
Aster sagittifolius Tail-leaved aster
Aster lateriflorus Side-flowering aster
Campanula americana Tall bellflower
Campanula rotundifolia Harebell
Cardamine concatenata Cut-leaved toothwort
Caulophyllum thalictroides Blue cohosh
Circaea lutetiana Canada enchanter's nightshade
Cryptotaenia canadensis Honewort
Desmodium glutinosum Pointed-leaved tick-trefoil
Dicentra cucullaria Dutchman's-breeches
Dioscorea villosa Wild yam
Eupatorium rugosum Common snakeroot
Fragaria virginiana Common strawberry
Galium triflorum Three-flowered bedstraw
Galium aparine Cleavers
Galium concinnum Elegant bedstraw
Galium boreale Northern bedstraw
Geranium maculatum Wild geranium
Geum canadense White avens
Hackelia cmx. Stickseed
Helianthus pauciflorus Stiff sunflower
Hydrophyllum virginianum Virginia waterleaf
Impatiens cmx. Spotted touch-me-not
Lactuca spp. Wild lettuce
Laportea canadensis Wood-nettle
Lilium michiganense Michigan lily
Maianthemum canadense Canada mayflower
Polygonatum pubescens Hairy Solomon's-seal
Polygonatum biflorum Giant Solomon's-seal
Prenanthes alba White rattlesnake-root
Pyrola elliptica Common pyrola
Ranunculus abortivus Kidney-leaf buttercup
Ranunculus recurvatus Hooked crowfoot
Rudbeckia laciniata Goldenglow
Sanguinaria canadensis Bloodroot
Sanicula marilandica Mariland black snakeroot
Sanicula gregaria Gregarious black snakeroot
Smilacina racemosa Racemose false Solomon's-seal
Smilax cmx. Carrion-flower
Solidago flexicaulis Zig-zag goldenrod
Strophostyles helvola Wild bean
Thalictrum dioicum Early meadow-rue
Thalictrum thalictroides Rue-anemone
23
Trillium cernuum Nodding trillium
Trillium grandiflorum Large-flowered trillium
Triosteum perfoliatum Horse-gentian
Uvularia grandiflora Yellow bellwort
Uvularia sessilifolia Pale bellwort
Veronicastrum virginicum Culver's root
Viola cm4 Violet
Viola cm1 Violet
Viola cm3 Dog violet
Zizia aurea Golden alexanders
Zizia aptera Heart-leaved alexanders
Grasses, Rushes and Sedges
Brachyelytrum erectum Bearded shorthusk
Bromus altissimus Broad-glumed brome
Carex pedunculata Long-stalked sedge
Carex pensylvanica Pennsylvania sedge
Carex blanda Charming sedge
Carex radiata Stellate sedge
Carex gracillima Graceful sedge
Carex deweyana Dewey's sedge
Carex rosea Rolled-up sedge
Carex intumescens Bladder sedge
Carex sprengelii Sprengel's sedge
Carex peckii Peck's sedge
Carex leptonervia Fine-nerved sedge
Carex sparganioides Sparganium-like sedge
Carex hirtifolia Hairy-leaved sedge
Elymus hystrix Bottlebrush grass
Elymus virginicus Virginia wild rye
Festuca subverticillata Nodding fescue
Leersia virginica White grass
Milium effusum Woodland millet grass
Oryzopsis racemosa Black-fruited rice-grass
Oryzopsis asperifolia Moutain rice-grass
Schizachne purpurascens False melic grass
Ferns and Fern Allies
Adiantum pedatum Maidenhair fern
Athyrium filix-femina Lady-fern
Botrychium virginianum Rattlesnakefern
Cystopteris fragilis Fragile bladder-fern
Cystopteris bulbifera Bulblet bladder-fern
Equisetum spp. Horsetail
Equisetum pratense Meadow horsetail
Onoclea sensibilis Sensitive fern
Osmunda claytoniana Interrupted fern
24
Exotic Invasive Species - Do Not Plant
Alliaria petiolata Garlic-mustard
Ambrosia artemisiifolia Common Ragweed
Arcticum minus Burdock
Asclepias syriaca Common Milkweed
Biddens Spp Beggar’s Tick
Carduus nutans Thistle
Digitalis lanata Grecian Foxglove
Elytrigia repens Quack-grass
Erigieron strigosus Rough Fleabane
Euphorbia esula Leafy Spurge
Glechoma hederaceae Creeping Charlie
Lotus corniculata Bird’s-foot Trefoil
Lythrum salicaria Purple Loosestrife
Medicago lupulina Black Medic
Mentha arvensis Field Mint
Oenothera biennis Evening-primrose
Phalaris arundinacea Reed canary-grass
Phleum pretense Timothy
Poa pratensis Kentucky Bluegrass
Polygonum convolvulus Black bindweed
Rhamnus cathartica Common buckthorn
Setaria Spp Foxtail Grasses
Solanum dulcamara Bittersweet nightshade
Solidage gigantean Smooth Goldenrod
Sonchus Spp Sow-Thistles
Taraxacum spp. Common dandelion
Tragopogon Spp. Goat’s Beard
Trifolium pretense Clover (red, white, alsike)
Urtica dioica Stinging Nettle
Verbascum thapsus Common mullein
Vicia cracca Cow Vetch
Information obtained from: Southern Mesic Oak-Basswood Forest Native Plant
Community. Great River Greening. Retrieved October 8, 2012 from:
http://www.greatrivergreening.org/plant_communities.asp
25
Appendix B: Degree of Invasion Field Sheet
26
Appendix C: Observed Species List
American Elm
Amur Maple
Big Bluestem
Black Ash
Black Eyed Susan
Black Locust
Black Walnut
Box Elder
Broad Leaf Plantain
Buckthorn
Bull Thistle
Bur Oak
Burdock
Canada Bluejoint
Canada Thistle
Cattail
Common Lambsquarters
Common Milkweed
Cottonwood
Creeping Charlie
Curly Dock
Fringed Brome
Garlic Mustard
Goldenrod
Gooseberry
Green Ash
Green Headed Coneflower
Grey Osier Dogwood
Hackberry
Honeysuckle
Kentucky Bluegrass
Lilac
Little Bluestem
Marsh Milkweed
Mint
Maiden Grass‐‐Miscanthus
Mulberry
Mullein
Nightshade
Northern White Cedar
Ox‐Eye Daisy
Paper Birch
Paper Birch
Poison Ivy
Poison Water Hemlock
Purple Loosestrife
Ragweed
Red Maple
Red Oak
Red Osier Dogwood
Reed Canary Grass
River Birch
Rough Fleabane
Scots Pine
Siberian Elm
Silver Maple
Smart Grass
Smooth Brome Grass
Sow Thistle
Spike Rush
Stinging Nettle
Sugar Maple
Sumac
Swamp White Oak
Switch Grass
Tamarack
Trembling Aspen
Violet
White Pine
White Poplar
Wild Grape
Willow
Yellow Foxtail
27
Appendix D: Map of City Subdivisions for Maintenance
Inspections
28
Appendix E: General Maintenance Agreement
STORM WATER QUALITY TREATMENT FACILITY
MAINTENANCE AGREEMENT
THIS AGREEMENT is made this ____ day of ______________, 2008 by and between
the City of Golden Valley, Minnesota, a municipal corporation (hereinafter referred to as
“City”) and _______________, (a Minnesota corporation or an individual) (hereinafter
referred to as “Owner”) with reference to the following facts and circumstances:
A. _________________________________ is/are the fee owner(s) of certain real
property situated in the City of Golden Valley, Hennepin County, Minnesota,
legally described as follows:
(Type Legal Here)
(hereinafter referred to as “Property”)
B. As a condition of its approval of the development of the Subject Property, the City
has required that the Owner enter into an agreement for the maintenance of the
Storm Water Quality Treatment Facility for the Property. This Storm Water
Quality Treatment Facility is located within the boundaries of the Property on
construction plans prepared by Owner.
C. The Owner desires to set forth his/its agreement with respect to the maintenance
of the Storm Water Quality Treatment Facility and the cost of such maintenance.
NOW THEREFORE, in consideration of the foregoing facts and circumstances, and for
other good and valuable consideration, the receipt and sufficiency of which is hereby
acknowledged, the parties hereto agree as follows:
1. For the purposes of this Agreement, maintenance of the Storm Water Quality
Treatment Facility shall include, but not be limited to, annual inspection, annual
maintenance reporting and certification by a professional engineer (provided by
Owner) that the facility is functioning in accordance with the approved plans and
minimum maintenance standards set forth by the City.
2. If necessary, Owner shall undertake at his/its expense periodic dredging or
removal of silt buildup and other deposited materials within the Storm Water
Quality Treatment Facility to maintain its treatment capacity and proper
operation, as established in the construction plans. Any maintenance needs
required by the Engineer shall occur within 30 days of the certified inspection.
3. Upon receipt of the annual certification of inspection and maintenance report, the
City will inspect the facility to ensure that the facility meets the minimum
maintenance standards. Annual inspection of the facility shall not render the City
responsible for identifying ongoing maintenance needs.
4. The Owner shall be solely responsible for the maintenance of the facility, and
shall bear all costs of such maintenance. If the Owner does not undertake the
29
necessary maintenance within thirty (30) days of notification by the City, the City
may contract such maintenance, but the costs reasonably incurred by the City for
contracting such maintenance shall be reimbursed to the City by the Owner.
5. The Owner, for itself/himself and respective successors and assigns, hereby
waives any statutory right which he/it may have to contest any assessment for
costs hereunder by the City.
6. The terms and conditions of this Agreement shall be binding upon, and shall
inure to the benefit of, the parties hereto and their respective successors and
assigns.
IN WITNESS WHEREOF, the parties hereto have caused this document to be
executed as of the day and year first above written.
TYPE FEE OWNER(S) NAME IN CAPS
By:
Its
STATE OF MINNESOTA )
) ss.
COUNTY OF HENNEPIN )
The foregoing was acknowledged before me this ____ day of ______________,
2008, by _____________________________________, the
_______________________________ of
______________________________________, a
____________________________________ under the laws of Minnesota, on behalf of
the ________________________________________.
Notary Public
30
CITY OF GOLDEN VALLEY
By:
Linda R. Loomis, Mayor
By:
Thomas D. Burt, City Manager
STATE OF MINNESOTA )
) ss.
COUNTY OF HENNEPIN )
The foregoing instrument was executed and acknowledged before me on this
____ day of ____________ 2008, by Linda R. Loomis and Thomas D. Burt, Mayor and
City Manager, respectively, of the City of Golden Valley, a Minnesota municipal
corporation.
Notary Public
This instrument drafted by:
BEST & FLANAGAN LLP (MVP)
4000 U.S. Bank Place
601 Second Avenue South
Minneapolis MN 55402-4331
31
CITY OF GOLDEN VALLEY
ENGINEERING STANDARDS FOR STORM WATER
TREATMENT FACILITIES
Pond Maintenance Requirements
1. Annual inspection, maintenance reporting and certification by a professional
engineer
(Provided by Owner). Information must be submitted to the City annually.
2. Excavate pond to original design capacity when one half (1/2) of the wet volume
of the pond is lost due to sediment deposition.
3. Remove floatable debris in and around the pond area including, but not limited
to: oils, gases, debris and other pollutants.
4. Maintain landscape adjacent to the facility per original design, including but not
limited to: maintenance of the buffer strip and other plant materials as per original
plan design.
5. Maintenance of all erosion control measures including but not limited to: rip rap
storm sewer outlets, catch basin inlets, etc.
Environmental Manhole Maintenance Requirements
1. Annual inspection, maintenance reporting and certification by a professional
engineer
(Provided by Owner). Information must be submitted to the City annually.
2. Maintenance should be performed once the sediment or oil depth exceeds the
established requirements recommended by the manufacturer.
3. Maintenance should occur immediately after a spill takes place. Appropriate
regulatory agencies should also be notified in the event of a spill.
4. Disposal of materials shall be in accordance with local, state and federal
requirements as applicable.
Rain Garden Maintenance Requirements
1. Inlet and Overflow Spillway – Remove any sediment build-up or blockage and
correct any erosion.
2. Vegetation
a. Maintain at least 80% surface area coverage of plants approved per plan.
b. Removal of invasive plants and undesirable woody vegetation.
c. Removal of dried, dead and diseased vegetation.
d. Re-mulch void or disturbed/exposed areas.
3. Annual inspection and maintenance efforts must be documented and submitted
to the City.
32
Appendix F: Maintenance Agreement Reminder Letter
Dear Maintenance Contract Holder,
The City of Golden Valley is reminding all maintenance agreement holders regarding
the responsibility of maintaining the storm water features on your property. These
ponds are important for maintaining the water quality of our local streams and lakes
by helping to filter pollutants and hold sediments.
As property owners with maintenance agreements, you are required to ensure that
these storm water features are meeting our standards for water quality and
vegetation management. As a private property owner, consistent maintenance is
necessary in order for these standards to be effective. Ponds that are managed
effectively for bioretention, infiltration, and water quality should include inspection of
the following:
Erosion along banks and structural components
Sedimentation within basin
Presence of invasive and aggressive native vegetation
Presence of healthy and abundant native vegetation
In order to maximize potential of your pond, here are some helpful “tips” to keep your
pond working in an effective manner
Aerate vegetation to increase infiltration
Store snow piles near filtration basins
Perform annual degree of degree of invasion inspections
More detailed information outlining the maintenance requirement can be found in your
maintenance agreement. A terminology list will be included within this letter as well for
your convenience. Please contact us if you have any questions or concerns regarding
management issues or your agreement.
The City of Golden Valley realizes that these maintenance agreements can often be
overlooked. Our hope is that you can recognize the importance of these storm water
features and comply with the rules and regulation set forth by the people of Golden
Valley.
Sincerely,
The City of Golden Valley
(763) 593-8030
33
Terminology
Best Management Practice – Method or technique found to be the most effective
and practical for means to obtain an objective
Bioretention – Best Management Practice (BMP) which utilizes soils and woody
and herbaceous plants to remove pollutants from storm water runoff
Erosion – Three step process involving detachment, transportation, and deposition
of soil particles
Filtration basin – Shallow depression utilized to retain and filter water before it
moves downstream
Invasive vegetation - Exotic plant adapted to very similar growing conditions as
those found in the region to which it is imported
Noxious Weeds-
Sediment - Loose particles of sand, clay, silt, and other substances which settle at
the bottom of a body of water
34
Appendix G: Invasive Plant Guide
Buckthorn (Rhamnus cathartica)
Structure/Size: Woody shrub to tree up to 23 feet tall.
Fruit/Seed: Black berries attached at leaf base.
Leaves: Elliptic in shape and glossy on the leaf surface. Tree retains green foliage well
into the late fall.
35
Amur Maple (Acer ginnala)
Structure/Size: Woody shrub to tree that reaches around 20 feet in height.
Fruit/Seed: Seeds are about an inch long and have two wings, they are quite numerous on the
tree.
Leaves: Leaves are longer than wide and have three toothed lobes. They turn a bright red in the
fall
36
Garlic Mustard (Alliaria petiolata)
Structure/Size: A small herb that can reach 2-4 feet in height.
Fruit/Seed: Has white four petalled flowers in May and has long slender seed capsules.
Leaves: Immature plants have several round leaves with scalloped edges. Mature plants have
alternately arranged triangular leaves with the same scalloped edges.
37
Burdock (Articum Spp.)
Structure/Size: A biennial herb that reaches up to 5 feet in height.
Fruit/Seed: Seeds are a sphere covered in velcro like spikes.
Leaves: Leaves are quite large and alternately arranged, large ruffled and triangular in shape.
Leaves are soft and fuzzy on the underside.
38
Creeping Charlie (Glechoma hederacea)
Structure/Size: Small ground cover herb, reaches 8 inches in height. Creeping stems create a
network over the invaded area.
Fruit/Seed: Blooms with small violet trumpet shaped flowers.
Leaves: Small round leaves, ruffled leaf edges.
39
Thistle (Cicerbita plumieri)
Structure/Size: Herb that grows up to 6 feet in height.
Fruit/Seed: Flowers are purple, produce small seeds with cottony parachutes.
Leaves: Easy to identify leaves covered in sharp spines,
40
Goldenrod (Solidago speciosa)
Structure/Size: A tall standing herb that is usually between 3-6 feet.
Fruit/Seed: Flowers are yellow and occur in large clumps at the end of the stem.
Leaves: Leaves are lanceolate and have toothed edges.
41
Smooth Bromegrass (Bromus inermis)
Structure/Size: A grass, reaching up to 3.5 feet in height.
Fruit/Seed: Seeds in separate spikes that droop from the end of the stem.
Leaves: Alternate on stem and 10 inches long on average, leaves less rigid than other grasses.
42
Reed Canary Grass (Phalaris arundinacea)
Structure/Size: A grass growing between 2-6 feet in height.
Fruit/Seed: A cluster of seeds on the end of a stem that is above the leaves.
Leaves: About a half inch wide at the base and waxy on the leaf surface.
43
Appendix H: Interview Process
Questions:
What are your predictions for what will lead to the best storm water management plan based on
your past experiences?
What future challenges and opportunities do you see for storm water vegetation management?
What do you believe are important points regarding public perception and management options?
44
Appendix I: Grant Information
Metro Conservation
Corridor Partnership
Habitat Restoration
Program
Great River Greening
Great River Greening is seeking partners to implement habitat restoration
on
protected lands and waters, with priority given to projects that 1) protect
and
restore water quality (projects must include monitoring), 2) protect,
restore, and
enhance land and habitat, and 3) reduce the spread of invasive species
along
streams, rivers, and land transportation routes.
Partners can be counties, watershed districts, cities, non-profits
and others within the 12-county metropolitan area. Projects must
be within a mapped Metro Conservation Corridor 1:1 match is suggested.
Applications due by February 1,
2012, but funding is allocated as
projects come in.
Wayne Ostlie
Director of Conservation Programs
Great River Greening
Saint Paul MN 55107
651-665-9500 x19
45
Pulling Together
Initiative
National Fish &
Wildlife Foundation
Program to help control invasive plant species, primarily through the work
of
public/private partnerships such as Cooperative Weed Management
Areas.
To be competitive, a project must:
-Prevent, manage, or eradicate invasive and noxious plants through a
coordinated program of public/private partnerships; and
-Increase public awareness of the adverse impacts of invasive and
noxious
plants.
Applications are accepted from private non-profit (501)(c)
organizations,local, county, and state government agencies, and
from field staff of federal government agencies.
It is anticipated that the Pulling
Together Initiative will award a
total of $1 million in 2012, with
the average award ranging from
$15,000-$75,000.
Pre-proposal deadline is May 25,
2012.
http://www.nfwf.org/AM/Template.cfm?Section=Charter_Programs_List&
CONTENTID=24713&TEMPLATE=/CM/ContentDisplay.cfm
Teal Edelen at 202-857-0166