7D - Information Item: Update on potential mussel introduction to Boulder Reservoir (aquatic invasive species) Attachment C
WEEKLY INFORMATION PACKET
MEMORANDUM
To: Mayor McGrath and City Council
From: Stephanie A. Grainger, Interim City Manager
• Paul Fetherston, Deputy City Manager
Maureen Rait, Executive Director of Public Works
Ned Williams, Director of Public Works for Utilities
Jan Geden, Director of Parks and Recreation
Mike Patton, Director of Open Space and Mountain Parks (OSMP)
Bret Linenfclser, Water Quality Coordinator, Utilities
Betty Solek, Water Quality Planner, Utilities
Matt Claussen, Urban Resource Manager, Parks and Recreation
Stacy Cole, Acting Boulder Reservoir Manager, Parks and Recreation
Eric Fairlee, Integrated Pest Manager, Open Space and Mountain Parks
Date: August 14, 2008
Subject: Information Item: iJpdate on Potential Mussel Introduction to Boulder Reservoir
EXECUTIVE SUMMARY:
Zebra and quagga mussels were first found in the United States (Great Lakes) in 1988. Since
their discovery, these aquatic invasive species have been causing environmental, infrastructure
maintenance and water quality issues in the east and midwest. These issues have resulted in
substantive financial and environmental impacts. Earlier this year, they were discovered in
Colorado reservoirs for the first time. The Boulder Reservoir Watershed Management Group
(F3RWMG), which is made up of staff from three departments, has been coordinating to develop
short- and long-term action plans to address potential introduction of the mussels. Key
information includes:
1. Recent discovery of zebra mussels in Pueblo Reservoir and quagga mussels in Lake
Powell and Lake Granby have raised concerns for the possible transport of these species
into Boulder Reservoir from boats and other watercraft.
2. To date, monitoring results for Boulder Reservoir and Carter Lake are negative for
mussel presence, but monitoring continues.
3. F3ased on general guidelines, Boulder Reservoir water quality, specifically calcium levels,
is suitable to support zebra and quagga mussel populations and reproduction. Colorado
State Parks and tl~e Division of Wildlife are currently monitoring Boulder Reservoir for
evidence of zebra and quagga mussel introduction.
4. Zebra and quagga mussel infestation cause increased maintenance issues, clogging intake
structures and pipelines which then require routine and expensive maintenance
(,4ttachment B).
AGENDA ITEM
5. 'These species create conditions that degrade the quality of water in the reservoir for
drinking water purposes.
6. Mussel infestation causes impacts to recreational activities: coating shorelines of
reservoirs, making them unattractive or unsuitable for recreation and harming boat
motors.
7. City of Boulder Parks and Recreation, Open Space and Mountain Parks and Utilities staff
have instituted and recommend additional preventative measures to address potential
mussel infestation of Boulder Reservoir.
FISCAL IMPACT:
2008-2009
This proposed action for the 2008 boating permit season requires minimal upfront capital cost for
the tagging supplies ($830). Additional staff will also be necessary to carry out the inspection,
cleaning and tagging program, to provide increased patrol for bait fishing restrictions and to
carry out the administrative and public education needs. Staffing costs for the balance of the
current boating permit season (through February 2009) are dependent on number of entry points
monitored. Staffing estimates range from $54,800 for inspections at two south shore entry points
to $144,370 to effectively address all south shore entry points.
Response to Infestation
If Boulder Reservoir were to be infested with zebra or quagga mussels, the initial actions taken
to combat this problem would be:
1. Replace Boulder Water Treatment Facility intake screens with copper screens
2. Install chemical feed systems to keep veligers (young, free-floating mussel larval stage)
from attaching to the intake pipeline and outlet works
3. Periodically operate the isolation valves to prevent accumulation of zebra mussels on the
valve components to ensure their ability to seal water tight
4. Increase the frequency of intake structure/pipeline inspections
5. Clean the interior of the pipelines.
These actions all will have on-going staffing requirements in addition to current operations.
Increased capital costs are currently estimated at greater than $400,000 and annual operating
costs are estimated at greater than $200,000.
COM,VIUNITY SUSTAINABILITY ASSESSMENTS A'~TD IMPACTS:
• Economic: If Boulder Reservoir becomes infested with the zebra/quagga mussel, there is
a potential for a change in the fishery and overall recreational opportunity on the
reservoir. This change could also result in a diminishment of the recreational value of
Boulder Reservoir and loss of a portion of the recreational revenue that supports the
recreation facilities. There may also be revenue losses to local community businesses that
support the boating visitors to Boulder Reservoir. Economic impacts on infested
drinking water infrastructure include lost production, time and effort expended to
remediate clogged systems, the replacement of damaged components, capital retrofit
projects to prevent future fouling, and long-term control and management activities.
AGENDA (TEM #1~D
• Environmental: Zebra mussel infestations can result in a significant shift in the ecology
of a lake or reservoir. In general, the presence of quagga and zebra mussels increases the
amount of algae growth in reservoirs due to the increased amount of water that is exposed
to light and the increased availability of nutrients. Other impacts on lakes from quagga
and zebra mussels include an increase in the aquatic plant growth due to increased water
clarity. The impact of zebra mussels on fisheries depends on the type of fish and their
feeding methods.
• Social: Actions to remedy or reduce the problem may include major, costly changes to
the treatment processes. The resulting costs and change in taste would have impacts on
all parts of the community. Users of the reservoir include city residents as well as
regional visitors from various demographics. Restrictions to recreational opportunities
can affect individual activities, age levels and specific programs currently offered.
BACKGROUI\~:
Regional Context
Zebra mussels are an invasive species that have recently arrived in the western U.S. This small
mussel has resulted in significant impacts to water providers, ecosystems and recreationists. The
quagga mussel is similar and related to the zebra mussel. Quagga mussels can have an even
greater impact on aquatic systems than the zebra mussel. This memorandum will. refer to both
zebra and quagga mussels interchangeably.
The zebra mussel was first found in the U.S. in 1988 and has subsequently spread through much
of the Eastern and Midwest portions of the country. They have infested waters in 23 states and
two Canadian provinces cast of the Continental Divide. in 2007, zebra and quagga mussels were
first found west of the Rocky Mountains and are now colonising in more than a dozen water
bodies including Lake Mead and Lake Powell. Phis year, the discovery of zebra mussels in
Pueblo Reservoir and quagga mussels in Lake Granby has raised new concerns regarding
potential introduction to Boulder Reservoir because they are now known to exist in popular
recreational waters within a day's drive of Boulder Reservoir. This issue is now a high priority
for Boulder.
Basic Mussel Biology
A mature female zebra mussel can produce a million eggs per year. Veligers are the free-
swimming larvae of the adult zebra and quagga mussel. Veligers and young adults can spread
via flowing water or by various types of watercraft that have not been thoroughly drained and
dried.
The veligers disperse in the water much like algae and attach to any hard service such as inlet
and outlet structures, boats and even aquatic species with hard shells. (See Attachment B.)
Water intake structures serve as an excellent habitat for mussel colonization. The continuous
flow of water into intakes carries with it a continuous source of food and oxygen and carries
away the mussels' wastes, while the structures themselves protect the mussels from predation,
siltation, and wave and ice scour. Mussels spread rapidly and can dominate a water body in a
year. Densities of over 70,000 individuals per square meter have been reported.
AGENDA ITEM
Environmental Changes
Zebra mussel infestations can result in a significant shift in the ecology of a lake or reservoir.
Mussels filter a large quantity of water. A single zebra mussel can filter one quart of water per
day. Given the large densities and the ability to filter, a significant amount of water is affected
daily, which increases the clarity of the water. Quagga and zebra mussels increase the amount of
algae growth in reservoirs due to the increased amount of water that is exposed to light and the
increased availability of nutrients due to their filtering processes.
Quagga and zebra mussels feed on particular types of algae upsetting the natural food chain in
lake systems. Other impacts on ecosystems from quagga and zebra mussels include;
• The increase in the aquatic plant growth in lakes due to increased water clarity.
• Fish species and their reproduction are diminished due to vegetative changes and
decreased food availability.
• Direct and in-direct impacts to other aquatic-dependent species such as birds,
amphibians and vegetation (e.g. bird botulism, lack of nesting areas, increase of non-
native plants).
• Blankets of blue green algae blooms can get washed onto shorelines and create odor
problems when the algae begin to decompose.
• Accumulations of decaying mussels and bottom-growing f lamentous algae can also
result in significant odor problems.
Transportation of Species
Mussels are transported between water bodies mostly by human-related mechanisms. The
overland transfer of boats and boat trailers containing zebra mussels is thought to be a primary
means of long-distance overland dispersal. Fishing equipment and bait buckets arc also known
transport mechanisms. Mussels adhere to components of a boat and can live outside of water for
several days. In addition, young mussels can be present in undrained portions of boats (live
wells, bilge wells, bait tanks, etc.).
Another potential transport mechanism is via canals and water transmission facilities from
infected reservoirs. The primary source of raw water to Boulder Reservoir is delivered from the
Colorado-Big Thompson project via Boulder Feeder Canal. The Colorado-Big Thompson (CBT)
system, including Boulder Feeder Canal, is managed by Northern Colorado Water Conservancy
District (NCWCD). Quagga mussels were positively identified in Granby Lake, ahigh-elevation
reservoir in the Colorado-Big Thompson system. (See Attachment A.)
'T'here is potential for mussels to be transmitted via the CBT system, but there are questions about
the ability of the mussel to survive in the water quality conditions of this high-elevation
reservoir. The interconnections of the CBT system illustrate the need to coordinate regionally on
prevention efforts-
aGEIVDA ITEM
Effects on Recreational L~se
In addition to the impacts to water transmission and treatment facilities, infestation of Boulder
Reservoir by mussels would impact recreation operations as well. Mussel shells can accumulate
on shorelines and beaches. Mussel shells are sharp and can cut people's feet and fishermen's
lines.
Zebra mussels can. attach to boat motors and props, affecting engine performance and sometimes
jamming steering equipment. Expensive motor damage can be caused if veligers are taken into
the cooling system. There, they can attach, grow and block intake screens, internal passages,
hoses, seacocks and strainers. (See Attachment B.)
Effects to Water Infrastructure
Fouling and clogging of raw water systems begins at the point of intake and can extend
throughout a facility to any discharge. At the point of intake, submerged intake cribs, trash racks,
pipelines and tunnels, and shoreline forebays and pumping wells are subject to severe fouling.
Once inside a drinking water treatment facility, the mussels can colonize any surface up to the
first oxidation or filtration stage where they are either killed or filtered from the water.
In the reservoir, these mussels have a taste for what we would consider the "good" algae and
reject the "bad" blue green algae. This encourages the growth of blue green algae, which
produces taste and odor issues. The taste and order impacts can be addressed through water
treatment but at an added cost.
A\ALYSIS:
Uncc these mussels are introduced to a water body, they are almost impossible to eradicate.
Preventative measures are essential to implement. Responsive actions and costs in the event of
introduction are also important to identify.
Preventative Measures
The following preventative efforts have been initiated by the Water Utility, Parks and
Recreation, and OSMP staff to-date:
1. Suspended one-day boat permits for power boats.
2. Host boaters open house on potential impacts of zebra and quagga mussels on July 29,
2408.
3. City press release on Aquatic Nuisance Species concern at Boulder Reservoir.
4. Educational signs advising of Aquatic Nuisance Species installed at boat ramps, north
shore and Coot Lake.
5. Evaluate options and funding for boat inspections and boat quarantine.
6. In progress: emergency regulations (per Boulder Revised Code 8-3-3, City Manager's
Rule) for Boulder Reservoir for regulatory enforcement capability of boating restrictions
as they relate to the prevention, inspection and monitoring for invasive species.
7. Restriction of walk-in watercraft (canoes, kayaks, etc.) from the north shore of Boulder
Reservoir and Coot Lake to encourage use of reservoir main entrance for monitoring and.
information dissemination.
AGENDA ITEM
8. Investigation of preventive actions that other nearby agencies, such as Westminster and
NCWCD, arc developing or implementing.
Response to Infestation
If infestation occurs, the Water utility will incur significant financial impacts. zebra or quagga
mussel growth and buildup in the city's water collection and treatment infrastructure would
prompt capital replacement and long-term maintenance costs for the Boulder Reservoir Water
Treatment Facility. Staff has developed very preliminary cost estimates to address mussel
impacts to the treatment facility, which include the intake structures from Boulder Feeder Canal
and Boulder Reservoir. Annual operating costs are estimated to increase by more than $200,000
for increased inspections, maintenance, cleaning and repair. Capital costs could increase by as
much as $400,000. These estimates are based on comparison of costs and facilities to those
developed for the City of Westminster Standley Lake facilities and must be refined as staff
continues investigation of potential vulnerabilities specif c to Boulder Reservoir and the water
treatment facility.
This change could also result in a diminishment of the recreational value of Boulder Reservoir
and a Loss of a portion of the recreational revenue. The revenue generated from 2008 boat permit
revenue as of mid-July is $294,500. There may also be revenue losses to local community
businesses that support the boating visitors to Boulder Reservoir.
NEXT STF;PS:
City staff are developing ashort-term plan to manage boating during the balance of the boat
permit season (August 2008- February 2009). Experience in other states has shown that
inspecting and cleaning boats greatly reduces the chances of contamination, but only a drying
period will effectively kill zebra and quagga mussels. The short-term plan would include the
following elements:
• Apply inspection and quarantine procedures at Boulder Reservoir to alt boats, including
untrailered boats such as kayaks, canoes and sailboats.
• Implement tagging program to document compliance with inspection and quarantine
procedures.
Minimal staffing costs for the balance of the boating permit season are estimated to be $54,800
to implement this short-term plan and will be shared equally between the Parks and Recreation
Department and the Water Utility.
A long-term plan for continued prevention and potential response is also under development.
This plan will include an evaluation of other management agencies' preventative actions.
For additional information, please contact Betty Solek at soleke@bouldercolorado.gov.
Attachment A: Figure of Northern Colorado Water Conservancy District System
Attachment B: Pictures of Mussel Impacts
AGENDA ITEM
Attachment ll
Northern Colorado Water Conservancy District System
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AGENDA ITEM #]~eD
Attachment E
PICTURES OF MUSSEL EFFECTS
WIP ATTACHMENT
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AGEIVQA iTEiN
Attachment E
PICTURES OF MUSSEL EFFECT'S
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AGENDA ITEM
Attachment E
PICTURES OF MliSSEL EFFECTS
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AGENDA ITEM #~I-D