Help keep ROLLINS AND SCOTTS FLAT RESERVOIRS MUSSEL FREE by cooperating with NID's new boat seal program.

• Boat Launching Protocols 
• Where and When Can I Get My Red Seals? 
• Where Can I Get My Blue Seals?   
• Watercraft Decontamination           
• Quagga, Zebra and Golden Mussel Facts       
• What Makes Golden Mussels So Invasive?

Frequently Asked Questions (FAQ), click here to download

Boat Launching Protocols

Effective March 20, 2025, NID has adopted new protocols for boat launching at Scotts Flat and Rollins reservoirs. 

NID tagging system and 30-day quarantine

Owners of any motorized watercraft wishing to launch must check in with NID on-site staff to be logged into the Watercraft Inspection and Decontamination (WID) program, which is administered by the California Department of Fish and Wildlife (CDFW).

Staff will attach a RED quarantine seal, which must remain for 30-days. The watercraft will not be permitted to launch at that time. The seal must remain intact, and the watercraft will not have been launched in any other waterbody during the quarantine period.  Boats with ballasts, bilges or live water tanks will have a 60-day quarantine.

Vessels that have finished the 30/60-day quarantine may return to the reservoir and have the seal removed by NID staff. Then they will be allowed to launch.

Can I decontaminate my boat instead?

Any watercraft wishing to launch sooner than the required 30-day quarantine period must have a hot-water decontamination performed by an authorized entity using the Watercraft Inspection and Decontamination (WID) program. These watercrafts are allowed to launch immediately following decontamination. Decontamination will not be valid unless a seal is applied to the watercraft and documentation is provided.

Blue seals permit re-entry without additional quarantine

Upon exit from the reservoir, all wataercrafts must have a BLUE seal attached by NID staff to be allowed to return and freely launch at District foothill reservoirs (Rollins and Scotts Flat). Otherwise, the watercraft will need to undergo another quarantine period or decontamination.

Non-motorized watercraft, such as kayaks and paddleboards, are not subject to participate in the NID quarantine program, yet are encouraged to be inspected by paddlers and arrive Clean, Drained, and Dry.

Why is this necessary?

The golden mussel was recently identified in the Sacramento-San Joaquin Delta and is the first known occurrence of these invasive species in North America. This species poses a significant and immediate threat to the ecological health of NID reservoirs and infrastructure, as well as all waters of the state, water conveyance systems, infrastructure, and water quality.

Where Can I Get My Red Seals?

You can get your red seal applied for free at the following boat launches at Rollins and Scotts Flat reservoirs:

• Rollins Orchard Springs - Thursday, Friday and Saturday (7:30AM – 4PM)
• Rollins Long Ravine - Thursday, Friday and Saturday (7:30AM – 4PM)

• Scotts Flat - Thursday, Friday and Saturday (7:30AM – 4PM)
• Cascade Shores - Wednesday and Friday (12 noon – 2PM) and Saturday (9AM-12 noon)

Where Can I Get My Blue Seals?

When you have concluded your 30/60-day quarantine, you may launch at either Rollins or Scotts Flat, as long as the RED seal is still attached to your boat. An NID employee will be able to remove that seal and the watercraft will be allowed to launch. A BLUE seal will be placed on your watercraft when your watercraft exits the water and upon departure.

Please note that to receive the BLUE seal, your boat must depart the lake during regular hours determined by NID.

How to Schedule a Watercraft Decontamination

At this time NID does not offer decontamnation services.  Shortly though, there will be services available at Rollins reservoir.  Greenhorn Campground is in the process of setting up their decontamination station, which includes a dip tank.  There are a few private enterprises, local and non-local, that provide decontamination to boats.  

Quagga, Zebra and Golden Mussel Facts

Physiology & Ecology of Golden Mussels 

Physical Description: Golden Mussels are sessile (non-moving) bivalves (two-shelled mollusks) whose color varies from a light golden to darker yellowish-brown and brown hues. Adult shells are typically 2-3 cm in diameter, with some reaching sizes of >4 cm. Golden Mussels typically grow in dense, reeflike colonies containing as many as 200,000 organisms per square meter.

Habitat: Originating from China and southeast Asia, Golden Mussels now inhabit shallow (< 10 m), freshwater aquatic environments worldwide. They tolerate many environmental stressors including wide ranges of temperature, pollution, and low oxygen. Preferring fresh water, Golden Mussels can nevertheless tolerate salinity of up to 10 ppt for as much as 30 days (Sylvester et al., 2013).

Life History: Mussel larvae develop into mobile veligers that propagate through a water body before reaching the settling (plantigrade) phase roughly 11-20 days after spawning. They then colonize hard surfaces and grow into adult mussels. Once attached, they remain sessile indefinitely.

Ecosystem Impacts: Golden Mussels are highly-effective ecosystem engineers, with the potential to catalyze broad-scale environmental change equivalent to invasions by Zebra or Quagga Mussels. They can dramatically reduce the abundance of both zooplankton and phytoplankton, leading to widespread food web impacts. Mussel invasions elsewhere have been associated with an increased frequency of potentially toxic blooms of Microcystis. Their propensity to rapidly colonize any available hard surface jeopardizes built infrastructure in any infested water bodies.

Monitoring Notes: Golden Mussel colonies typically attach to solid substrates, preferring piers, moorings, rocks, downed trees, or other submerged objects. The do not grow in soft, unconsolidated sediments and are therefore unlikely to be detected using typical methods for monitoring the benthos (e.g., grabs and cores).

Quagga & Zebra Mussels

Quagga Mussels (Dreissena rostriformis bugensis) are a small freshwater mollusk.  They are an invasive species native to Russia and Ukraine and are thought to have been transported to the Great Lakes region in the ballast water of transoceanic ships. They have some diagnostic features to identify them from zebra mussels.  The quagga’s shell has a rounded angle, a convex ventral, and their color varies from black, white, cream, but they are generally paler (U.S.G.S.). The quagga causes problems because they are “water filterers” and are able to remove large amounts of phytoplankton and suspended particulates from lakes and streams (Sea Grant Michigan). This can have a potential to alter the balance of the aquatic food web.  The mussels’ tissues also trap contaminants, which can be exposed to wildlife if they are eaten.  Like zebra mussels, the quagga also clogs water structures that can reduce pumping capabilities for water treatment (Sea Grant Michigan).

Zebra mussels, a native species of Eastern Europe, were first introduced in the United States through ballast water released into the Great Lakes in the late-1980s. Quagga mussels soon followed.

Great efforts have been made to prevent the spread of these freshwater mollusks west of the 100th Meridian. In January 2007, Quagga mussels were discovered in Lake Mead and later in other reservoirs of the Lower Colorado River. Quagga mussels were discovered by Metropolitan Water District divers on Wednesday, Jan. 17, 2007 at Lake Havasu, and again on Friday, Jan 19, 2007 about 14 miles to the north. In January 2008, Zebra mussels were discovered in San Justo Reservoir in San Benito County, California. The spread of these mussels to additional California waters will seriously impact the state’s aquatic environment and water delivery systems, endangering recreational boating and fishing.

What Makes Golden Mussels So Invasive?

There are four primary characteristics that make these mussels incredibly invasive:

• FREE SWIMMING LARVAE – Larval mussels swim in the water column for the first month of their life. Because they are free swimming and extremely small, they can be drawn into engines, ballast tanks, live wells and bilges, and be easily transported from one body of water to the next.
• BYSSAL THREADS – Zebra, quagga and golden mussels have byssal threads that allow them to attach to any stable substrate in the water including rocks, plants, fiberglass, plastic, cement, steel, and even onto other mussels creating a thick layer as seen in some of these photos.
• RAPID REPRODUCTION RATE – They have a very rapid reproduction rate, spawning year-round (if conditions permit), where 1 single female can produce up to one million eggs in a year.
• FILTER FEEDERS – Feeding off of plankton (the foundation of the aquatic food chain). It has been observed that a mussel can filter up to a liter in a day. Anything they have filtered through that they do not eat is rejected as a mucous known as pseudofeces. This pseudofeces is known to decrease DO and increase pH.

What to do if you think you have been to an infested waterbody?