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Standley Lake Trailered Boating FAQs

The decision to cancel permits for trailered boats and restrict this type of recreation on the lake is due to increased concerns about infestation from zebra and quagga mussels (ZQM). These invasive species   are spreading to bodies of water throughout the United States. The mussels often spread by attaching to boats or trailers.

Many boats that are launched off a trailer are powerboats that are equipped with ballast tanks. Ballast tanks are located within the boat’s hull and fill with lakewater to keep the boat lower in the water as its speed increases. The tanks cannot be fully drained or visually inspected to confirm they’re clean. This provides an opportunity for ZQM to remain inside the tanks and enter new bodies of water. Additionally, many boat trailers allow water to enter their frames. The inside of the frames also cannot be sufficiently drained.

Preserving water quality at Standley Lake is staff’s highest priority as this is the drinking water supply for three cities and more than 300,000 people.  Multiple studies have shown that the largest threat to the transport of ZQM from one body of water to another is a trailered boat that has ballast tanks. Both trailers and ballast tanks trap water that is undetectable and can harbor ZQM larvae for extended periods making them unable to decontaminate 100% effectively. 

Paddle boards, canoes, kayaks, and inflatable rafts do not have internal compartments, like ballast tanks, and do not require a trailer to transport. These vessels can easily be decontaminated and inspected and do not hold water that is undetectable. 

In addition to decontamination, trailered boats have been subject to a 35-day quarantine before being allowed to launch at Standley Lake. The length of the quarantine is based on a 2013 study that found ZQM can potentially survive up to 27 days in ballast tanks.

Westminster staff reviewed boat launch data for trailered boats with a 2018 Standley Lake permit and found as many as 24 boats had circumvented the quarantine and decontamination program. In most cases, this was a result of a small number of permit-holders tampering with quarantine measures. Trespassing notices were issued.

After months of discussion and deliberation involving a community-driven process in which staff and a citizen taskforce  worked closely to create and review potential solutions, none were found and the city decided in November 2019 to prohibit trailered boating on Standley Lake.

Recreation on Standley Lake

Allowed: Car top boats and paddle craft (car top vessels are those that can be lifted onto and taken from the top of a passenger vehicle or from the bed of a truck), multi-chambered inflatable devices and electric trolling motors. Maintenance, rescue and patrol boats operated by City personnel will also continue to be allowed on the water but are subject to decontamination and if necessary, quarantine protocols.

Prohibited:Trailer-hitched boats, motorized gas-powered boats and engines, sailboats, belly boats, single-chambered flotation devices (including inflatable rafts, inner tubes and inflatable mattresses, pool toys or any floating device not designed for open water use).

Yes. These types of watercraft will still be allowed provided they can be launched without a trailer and go through the mandatory decontamination spraying process just like in previous years. Decontamination of these types of watercraft has been extremely effective in removing ZQM from surfaces that can make contact with the water.

Staff shares the concern that the type of vessels mentioned can more easily be launched in remote areas outside of the boat launch. This is an issue that staff at Standley Lake will continue to diligently monitor and control. Staff is in agreement, it is not acceptable to be able to launch vessels anywhere on the lake. The ANS program is intended to regulate all types of boats, not just some.         

Many boats that are launched off a trailer are powerboats that are equipped with ballast tanks. Ballast tanks are located within the boat’s hull and fill with lakewater to keep the boat lower in the water as its speed increases. The tanks cannot be fully drained or visually inspected to confirm they’re clean. This provides an opportunity for zebra/quagga mussels (ZQM) to remain inside the tanks and enter new bodies of water. 

Additionally, many boat trailers allow water to enter their frames. The inside of the frames also cannot be sufficiently drained.

Preserving water quality at Standley Lake is staff’s highest priority, as this is the drinking water supply for three cities and 300,000 people. Multiple studies have shown that the largest threat to the transport of ZQM from one body of water to another is a trailered boat that has ballast tanks. Both trailers and ballast tanks trap water that is undetectable and can harbor ZQM larvae for extended periods making them unable to decontaminate 100% effectively. 

Paddle boards, canoes, kayaks, and inflatable rafts do not have internal compartments, like ballast tanks, and do not require a trailer to transport. These vessels can easily be decontaminated and inspected and do not hold water that is undetectable.

As zebra and quagga mussels spread to more bodies of water in Colorado and the west, the level of risk increases, and that makes the prospect of returning trailered boats to Standley Lake increasingly unlikely.

Please remove any Westminster tag you may currently have on your boat. All tags are invalid until further notice. Should a boating program resume in the future, instructions regarding boat permitting will be provided.

Westminster collected approximately $480,000 in revenuefrom trailered boat permits in 2018. This revenue will not be available in thefuture. However, Westminster has increasingly worked to develop expandedrecreational programs at Standley Lake, which continue to grow and thrive. In2019, following the initial ban on trailered boating, Standley lake saw a 35 percent increase in lake visitation.

All full-time staff at the lake hold state certifications as Stage II Inspectors and Decontaminators and have been certified annually since the inception of the state program (2008). Being a certified WID (watercraft inspection and decontamination) site provides access to the state’s mobile WID application. This application has been utilized by Standley Lake staff for the last four years to verify other agency tags that were placed on a boat previous to coming to Standley Lake. This allowed boats entering Standley Lake to bypass the decontamination and quarantine requirements because staff was able to verify that the boat had not launched on another water body since the previous season (staff would not allow the bypass of the quarantine and decontamination if the boat had launched on any water body after the winter season had ended). Staff did not utilize the WID application at the boat ramp because the application did not provide data in “real-time” when logging the information into the application.

Based on conversations with the state over the past two months, staff were notified by the state that the application was recently updated and would now be able to deliver search results in “real-time” as the boat information was logged. Standley Lake staff were already committed to utilizing the State WID mobile application at the boat ramp for the 2019 season.

Westminster is a leader in adopting decontamination spraying routines and imposing quarantines on boats. These measures have been adopted at other lakes to prevent zebra and quagga mussel larvae from getting established. In addition to staff experts, the city has brought in outside experts to verify the risk of acquiring zebra mussels as well as determine the impact of an infestation. The immediate conclusion is that the threat is just too great to move forward with the policies that are in place.

The National Marine Manufacturers Association (NMMA) has made aquatic nuisance species (ANS) a top priority and recently came to Colorado, visited several Watercraft Inspection and Decontamination (WID) sites, and created a digital essay, titled "Keeping Colorado Waterways Clean and Sustainable." View the essay, watch a mini-documentary on the efforts out west and a view a walk-through of the decontamination process.

Barr Lake State Park 
Directions: Take I-76 northeast from Denver, exit on Bromley Lane. Go east to Picadilly Road, then south to the park entrance. 
Fee: Please see Barr Lake State Park Fee Information for additional information. 
Boating: Only sailboats, hand-propelled craft and boats with electric trolling motors or gasoline motors of 10 horsepower or less are permitted on Barr Lake. A boat ramp is located adjacent to the north parking lot. |
Fish: Channel catfish, smallmouth and largemouth bass, rainbow trout, walleye, bluegill, wiper and tiger muskie are among the species that have been stocked at Barr Lake by the Colorado Colorado Parks & Wildlife. 
Water Acres: 1,918 
Elevation: 5,100 feet 
Managing Agency: Colorado Parks & Wildlife. For more information, call 303-659-6005. 

Bear Creek Lake 
Directions: 1/8 mile east of Highway C-470 on Morrison Road. 
Fee: $10 per vehicle 
Boating: 10 horsepower maximum 
Fish: Tiger muskie, rainbow trout, smallmouth bass and saugeye. 
Water Acres: 110 
Elevation: Lake: 5,558 feet; Mt. Craven: 5,779 feet 
Managing Agency: City of Lakewood. For more information, call 303-697-6159. 

Boulder Reservoir
Directions: From Highway 36, go north to the Longmont Diagonal (Highway 119) and turn northeast. At Jay Road turn west and then north almost immediately onto 51st street. 
Fee: See Boulder Reservoir Fees
Boating: All watercraft require permit, must launch from south shore after going through inspection
Fish: Walleye, channel catfish, black crappie, bluegill, largemouth bass, yellow perch and rainbow trout 
Water Acres: 540 
Elevation: 5,173 feet 
Managing Agency: City of Boulder Parks and Recreation. For more information, call 303-441-3461.

Boyd Lake State Park 
Directions: Exit I-25 west at U.S. 34 near Loveland, turn north onto Madison Avenue, then follow the signs. 
Fees: Please see Boyd Lake State Park  fees.
Boating: Two paved launch ramps. A six-lane ramp is located north of the swim beach, while a two-lane ramp is located just north of the group picnic area. The entire lake is open to boating and sailing. Only the south end of the lake is open to water-skiing. The ski pattern is counterclockwise. 
Fish: Bass, catfish, crappie, perch, rainbow trout and walleye 
Water Acres: 1,750 
Elevation: 4,958 feet 
Managing Agency: Colorado Parks & Wildlife. For more information, call 970-669-1739. 

Carter Lake 
Directions: I-25 north to Colorado Highway 56 (Berthoud exit) west, follow the signs to Carter Lake. 
Fee: $6 daily fee; $6 daily boat fee; $7 camping 
Boating: No restrictions 
Fish: Kokanee salmon 
Water Acres: 1,140 
Elevation: 5,760 feet 
Managing Agency: Larimer County. For more information, call 970-679-4570.

Chatfield State Park 
Directions: From Denver, take Wadsworth Blvd. (Colorado Highway 121) south past C-470, and turn left into the Park at the Deer Creek entrance. As an alternate route, take Santa Fe Blvd. south to Titan Road, turn west on Titan Road to Roxborough Park Road, and turn north to the Plum Creek entrance. 
Fees: Please see Chatfield State Park Fees. 
Boating: Three boat ramps, water-skiing, sailboarding and personal watercraft 
Fish: Trout and bass, channel catfish, yellow perch, crappie, bluegill, sunfish and carp. The lake is periodically stocked with rainbow trout and other fish by the Colorado Parks & Wildlife.  
Water Acres: 1,550 
Elevation: 5,430 feet 
Managing Agency: Colorado Parks & Wildlife. For more information, call 303-791-7275. 

Cherry Creek State Park 
Directions: One mile south of I-225 on Parker Road, adjacent to south Denver.
Fees: Please see Cherry Creek State Park Fees. 
Boating: Two boat ramps, water-skiing, personal watercraft and sailboarding 
Fish: Trout, walleye, bass, crappie, pike, carp and catfish, state record walleye have been caught at the reservoir 
Water Acres: 880 
Elevation: 5,550 feet 
Managing Agency: Colorado Parks & Wildlife. For more information, call 303-699-3860.

Horsetooth Reservoir
Directions: Take I-25 to the Fort Collins exit (Harmony-Tinmath), go west on Harmony, then north on Taft Hill Road about 1 mile to County Road 38E, take County road 38E west to the reservoir. 
Fee: $7 daily 
Boating: No restrictions 
Fish: Largemouth and smallmouth bass, walleye, saugeye, white bass and wiper 
Water Acres: 2,000 
Elevation: 5,400 feet 
Managing Agency: Larimer County. For more information, call 970-679-4570.

Boats that did not return to Standley Lake were not included in the 24 boats mentioned. Boat launch data from the state indicates 312 launches by 84 different permit holders on other lakes. Only the 24 that returned and launched without going through the proper decontamination and quarantine were listed. Regarding the violations, the permit holders that were verified to have violated the program were given trespass from Standley Lake, with a 30-day review process (which is standard with the trespass program).

The information that staff requested from the Colorado ANS Specialist regarding the 2018 Standley Lake boat permit holders was received by staff on Jan. 31, 2019. This was the first time that staff requested this information from the State of Colorado ANS Program. The intent of gathering this information was to verify that the current ANS program in place at Standley Lake was working and effective. Staff did not expect the information that 24 boats had violated the ANS program at Standley Lake. The violators will go through the city’s due process of being issued a trespass notice with a 30 day window to dispute the charges. After that process, final decisions will be made on trespass.

No documentation has been lost. As noted in the City of Westminster's response to Colorado Open Records Act (CORA) requests: “disclosing the names, addresses, etc. of specific users of Standley Lake is also denied, based upon:

C.R.S. 24-72-204(3)(a)(IX) - The custodian shall deny the right of inspection of "[n]ames, addresses, telephone numbers, and personal financial information of past or present users of [...] public facilities, or recreational [...] services that are owned and operated by" the City.

The city did respond to a request for records that don’t exist, as follows:  “Please note that the City is not and never has been in possession of data related to the makes/models of boats, as this information is not collected by the City and there are no responsive documents which could provide such information.”

Zebra and Quagga Mussels

Once ZQM are established in a body of water, they will begin to attach to every hard surface. This includes drinking water infrastructure. Standley Lake is Westminster’s sole source for drinking water. Water from the lake enters Westminster’s treatment system directly, so an infestation of ZQM in the lake would threaten to clog intake pipes and spread inside other pipes. ZQM can also create algae blooms that can cause taste and odor issues in drinking water, or more seriously, allow for toxic algae blooms that can render a water supply unusable.

View the 2010 Quagga/Zebra Mussel Risk Assessment and Treatment Study

All impacts to water quality are reviewed on a constant and ongoing basis.  ZQM was not a concern when the Intergovernmental Agreement (IGA) was drafted 25 years ago. It is a significant concern for Colorado now. In January 2007, quagga mussels were detected in Lake Mead and Lake Powell. In the following decade, ZQM spread reservoir by reservoir across the West.

In 2017, quagga mussels were detected in Green Mountain Reservoir, which is fewer than 100 miles away from Standley Lake. Thanks in part to strict ZQM programs across the state, the majority of the cases of ZQM-positive tests have not resulted in established populations; however, the number of lakes testing positive for ZQM is rising. Standley Lake provides ideal conditions for ZQM and can support a thriving ZQM population.

Standley Lake Regional Park is known throughout the nation for implementing proactive measures to address ZQM threats. The city has been dedicated to researching ZQM threats and has been proactive in implementing measures (e.g. extended quarantine period, spray enhancements, spraying all watercraft that touch the lake, etc.) to protect our water quality since the inception of the boating program.  

A ZQM infestation in Standley Lake would require new systems to be developed to prevent the mussels from clogging essential water infrastructure. City staff estimate these systems would cost approximately $10 million to install and $3 million to operate each year. These costs would impact rates for Westminster water customers. Westminster, Northglenn and Thornton have all committed, through a recreational intergovernmental agreement, to mutually protect the drinking water supplies that all three cities rely on. ZQM infestation could translate to a meaningful increase in monthly water rates for Westminster residents.

The lake’s ecosystem would also be severely impacted. ZQM populations can filter massive amounts of water, but in doing so would eliminate the microscopic organisms that form the base of the food chain. This would cause a chain reaction up the food chain resulting in destruction of the now healthy ecosystem in Standley Lake. Additionally, changes in water chemistry would cause the existing invasive aquatic plant, Eurasian milfoil, to increase in density as the beneficial milfoil weevils population declines.

Ultimately, the cost mitigating a ZQM infestation would be borne by the water rate payers and taxpayers of the City of Westminster. Once established, a ZQM infestation can only be mitigated, not eliminated. This means that a ZQM infestation would result in permanent and significantly increased water rates for lower quality water.

Standley Lake Regional Park and Wildlife Refuge is a valued recreation destination for thousands of local residents. Since ZQM was first identified as a threat to Colorado waters in 2007, Westminster has had a ZQM protection plan in place for the lake. This protection plan was the first of its kind in Colorado, and Westminster has been a leader in its approach. However, as more information has become available over the years, and key information came to light over the winter about ZQM, staff has identified that even this robust program is not capable of being fully protective of the lake. The risk is too large to accept.

Westminster Public Works and Utilities Department tests for the presence of zebra and quagga mussels in Standley Lake throughout the year. So far, testing has not detected these species in Standley Lake. Testing will continue into the future.

Composite samples are taken at 5-6 locations across the lake. This is done twice every month as long as there isn’t ice on the water, which prevents sampling. There is also an annual shoreline survey that looks for adult mussels that have adhered to hard structures. Generally a quarter of the shoreline is surveyed annually.
No. There has never been a positive test result for zebra or quagga mussels (either veliger or adults).

Green Mountain Reservoir (in Summit County) tested positive for quagga mussels on Aug. 18, 2017 and is currently listed as a “containment” reservoir. Lake Pueblo tested positive for mussel larvae, know as veligers, in 2007, 2008, 2009 and 2011, but, after several years of clean reports, it was delisted from so-called containment protocol in January. 

Blue Mesa, Granby, Shadow Mountain, Willow Creek, Tarryall and Jumbo reservoirs and Grand Lake tested positive for zebra or quagga veligers in 2008, but all were delisted in 2014 and are now considered free of the invasive species. There are several important factors to consider with these positive test results. Testing does not determine how many veligers were present in the lake.  It is possible that there were not enough veligers to establish a sustained population.  It is also possible that the veligers were not living. Also, despite significant work with multiple experts, there is always the possibility that there is something else at play. 

That said, based on best available information from multiple sources, Standley Lake is well within the habitable limits of zebra/quagga mussels.

There is no way to treat for zebra/quagga mussels once they are introduced, and the impact to water infrastructure would be significant. The most feasible way to limit infrastructure impacts is by introducing chlorine at the infrastructure. This would cause an increase in disinfection byproducts (which are regulated carcinogenic compounds) into our drinking water supply. We also know that the current ANS program has shortcomings. Standley Lake is a water supply for 300,000.  Westminster water rate payers, specifically, bare all of the financial risk of ANS introduction (specifically $10 million in capital costs plus $3 million annually in perpetuity), and the water delivered to those 300,000 people would be impacted if zebra/quagga mussels were to establish.  Colorado has, to date, not had a sustained infestation. This is true, but the risk to the water supply remains very real.

Standley Lake Boating Taskforce

City staff worked diligently, in cooperation with the boating community, to find a solution to restore trailered boating without compromising water quality. Considerable staff time and financial resources were spent working with the Standley Lake Boating Taskforce (SLBT). 

Although finding an acceptable solution to restoring trailered boating was not found and will no doubt be disappointing to the group, staff entered into this effort with the belief and directive to find a solution together, and hope that the relationships built during the process will be helpful moving forward.

Extensive documentation of SLBT meetings, including meeting recordings and supporting materials, is available on the city's SLBT page. The SLBT purpose and objectives were clearly outlined prior to the start of the group’s work and can be found on the SLBT page.

This is a city staff decision. The Standley Lake Boating Taskforce is an advisory body. The SLBT Memorandum of Understanding states: “The SLBT will be an advisory body rather than a decision-making body. Consensus will be the goal for recommendations.”

The stated purpose of the group was to “evaluate options for restoring trailered boats to the lake without compromising the quality of the water.”

The main criteria used in making this decision included:

  • Standley Lake is the source of drinking water for 300,000 people. The city's number one priority is providing reliable, quality drinking water.
  • There is a growing threat of ZQM infestation in Colorado waters from trailered boating. The number of mussel-infested boats intercepted by Colorado Parks and Wildlife has more than tripled since 2017.
  • Months of discussion and evaluation by the Standley Lake Boating Taskforce, boaters and staff preceded this decision. A solution has not been identified to allow trailered boats back on the lake without the risk of compromising water quality. This was affirmed in a 4-1 vote by the Standley Lake Boating Taskforce on Tuesday, Oct. 15, and through continued testing by staff since that time.
  • The Standley Lake Intergovernmental Agreement (“IGA”) governs the use of the lake. We are working with our partners, Northglenn and Thornton, on a renewed IGA. Both partners have expressed concerns about trailered boats on the lake.
  • If ZQM establish in Standley Lake, the cost of aquatic nuisance species remediation for Westminster alone is estimated at $10 million in capital expenses and $3 million in annual operating costs, significantly increasing the cost to deliver water.
  • The establishment of ZQM will permanently change the ecology of Standley Lake, resulting in taste and odor issues and a reduction in water quality.

The Standley Lake Boating Taskforce (SLBT) met on Tuesday. Oct. 15, 2019. A full audio recording of the meeting is available on the SLBT web page. The primary purpose for calling that meeting was for the tagging subcommittee to provide a recommendation to the SLBT (the subcommittee had split opinions on the solutions evaluated to date) and for the SLBT to make a recommendation to the city regarding trailered boating. The agenda for this meeting included this information:

The recommendation from the tagging subcommittee was split. Staff provided an update on the false reports generated by the Noke system and explained how aspects of the hardware solutions they reviewed could be circumvented. Friends of Standley Lake (FOSL) felt that, while the hardware could be circumvented, it was detectable enough to be considered a solution. 

SLBT was expecting to make a recommendation for the 2020 season based on the presentations by the tagging subcommittee. Because FOSL asked at the meeting for new hardware to be considered, SLBT voted on three recommendations.

  • Based on the solutions evaluated and tested by the tagging subcommittee in the months prior to this meeting, and presented to the SLBT that day, would SLBT recommend returning trailered boats back to the lake? SLBT voted 4-1 that they would not make that recommendation.
  • Does the SLBT recommend continued vetting of the new potential solutions brought forward for the first time at the Oct. 15 meeting? SLBT voted 5-0 to vet these options.
  • After vetting, if these solutions are recommended by the subcommittee (staff and FOSL), would SLBT recommend putting trailered boats back on the lake with these solutions alone and without Noke (a technology solution that showed promise, but has technical issues that the company is working to resolve). SLBT voted 4-1 that they would recommend moving forward without Noke if the other solutions are recommended by the subcommittee.

Standley Lake Recreational Intergovernmental Agreement

The Standley Lake Recreational Intergovernmental Agreement (IGA) is an agreement between Westminster, Northglenn and Thornton that governs the use of the lake. The current IGA allows for recreational uses at Standley Lake that all three cities agree on, and also gives all three cities a framework for resolving disputes related to the water supply instead of litigation, which would be the only recourse in the absence of the IGA. [HR1]

The current IGA was drafted 25 years ago and city staff from all three cities are working on the details of a renewed IGA. Preliminary communication regarding the new IGA has begun between the three cities. No decisions have been made about the future of boating at Standley Lake as part of this process.

The City of Westminster is the sole provider of all recreation activities at Standley Lake. The other IGA partners have never been involved in recreation activities and are not resourced, including staffing, in this regard.
Westminsterseeks to negotiate a renewed IGA that allows for the continued operation ofrecreational activities at Standley Lake which prevent less of a threat to thewater system, while also addressing the distribution, control over, andliability for risks to those systems from recreational activities.