Water Quality Monitoring at Whiskeytown

Water quality sampling locations around Whiskeytown lake.

NPS

To protect the health and safety of our visitors, the National Park Service at Whiskeytown National Recreation Area monitors water quality at our designated swim beaches every Monday during the summer months. On holidays such as Memorial Day, July 4, and Labor Day, testing is done on Sunday's in order to capture the most accurate peak visitation times. Please see below for the testing site locations and the current status:

• Brandy Creek Beach

• Brandy Creek Marina

• East Beach

• Whiskey Creek Group Picnic

• Oak Bottom Beach

• Clear Creek (Tower House Historic District)

Green states that measurable contaminates are below the threshold of concern.
Yellow is a single test with results that are at or exceeding the threshold of concern. Results of a follow up test are pending.
Red is multiple, daily tests have returned results that are at of exceding the threshold of concern.

E. coli is an indicator bacteria used to identify fecal pollution from human, pet, or wildlife waste. Most strains of E. coli are harmless, but elevated levels indicate that pathogens could be present and sicken swimmers and other users of the creek.

To reduce the probability of illness from water borne pathogens, samples are gathered weekly at our swim beaches from May through September and the results are compared to state and federal water quality standards. Although uncommon, sometimes water quality standards are exceeded, and swimming advisories are posted. Since 2005 this has occurred twice, once at Brandy Creek Beach (2018) and once at Whiskey Creek Group Picnic Area (2021).

The primary source for degraded water quality includes humans, pets, and wildlife, specifically Canada geese which can be prolific at our beaches during the summer. A single Canada goose can poop 1 to 3 pounds per day!! Please do your part to keep our beaches and lake clean by abiding by the following practices…

• Don’t feed wildlife or leave food unattended.

• Bag your pet’s poop and place it in the trash.

• Keep your pet off the official swim beaches - they are not allowed.

• Always use the restrooms provided.

• Shower before and after getting into the lake. Brandy Creek Beach and Oak Bottom Beach offer shower facilities.

• Check and change diapers before allowing infants into the lake and check frequently while in the lake.

Why is Whiskeytown Lake Usually Clean and Clear?

Whiskeytown Lake has two separate sources of water: 1) Clear Creek and its tributaries and 2) during the summer, Clear Creek Tunnel, a manmade tunnel that connects Whiskeytown Lake with the Trinity River watershed at Lewiston Lake. Trinity Lake and Lewiston Lake act as a “settling pond” for sediment before the water is transferred to Whiskeytown Lake. Additionally, Whiskeytown Lake has two water levels, winter and summer, which minimizes shoreline erosion to two levels as compared to constant water level changes at other reservoirs.

Whiskeytown Lake generally has very good water quality and a major reason for this is because all the water flowing into the lake comes from rural, mountainous, forested landscapes. While agricultural land as well as urban and suburban environments pollute waterways substantially, since there is very little agriculture and only a few small towns upstream of Whiskeytown Lake and Lewiston Lake, Whiskeytown Lake is clean. Furthermore, most of this upstream land is protected from significant human development because it is held in trust by the federal government for the American people; the land is specifically managed by the U.S. Forest Service and Bureau of Land Management.

Swimmers Itch

Although not an indicator of poor water quality, the NPS sometimes receives complaints about swimmers itch during the summer season and most complaints come from swimmers at Brandy Creek Beach. Most people are not sensitive to swimmer’s itch and victims are encouraged to consult a physician.

Swimmer’s itch, also called cercarial dermatitis, appears as a skin rash caused by an allergic reaction to certain microscopic parasites that infect some birds and mammals. These parasites are released from infected snails into fresh and salt water (such as lakes, ponds, and oceans). While the parasite’s preferred host is the specific bird or mammal, if the parasite comes into contact with a swimmer, it burrows into the skin causing an allergic reaction and rash. Swimmer’s itch is found throughout the world and is more frequent during summer months

The adult parasite lives in the blood of infected animals such as ducks, geese, gulls, swans, and certain mammals such as muskrats and raccoons. The parasites produce eggs that are passed in the feces of infected birds or mammals.

If the eggs land in or are washed into the water, the eggs hatch, releasing small, free-swimming microscopic larvae. These larvae swim in the water in search of a certain species of aquatic snail.

If the larvae find one of these snails, they infect the snail, multiply and undergo further development. Infected snails release a different type of microscopic larvae (or cercariae, hence the name cercarial dermatitis) into the water. This larval form then swims about searching for a suitable host (bird, muskrat) to continue the lifecycle. Although humans are not suitable hosts, the microscopic larvae burrow into the swimmer’s skin, and may cause an allergic reaction and rash. Because these larvae cannot develop inside a human, they soon die. (Centers for Disease Control and Prevention Website, 2021).The symptoms of swimmer’s itch are:

• Tingling, burning, or itching of the skin.

• Small reddish pimples.

• Small blisters.

For treatment recommendations of swimmer’s itch visit the Centers for Disease Control and Prevention (CDC) Website or consult a physician.What can be done to reduce the risk of swimmer’s itch?

• Do not swim in areas where swimmer’s itch is a known problem or where signs have been posted warning of unsafe water.

• Do not swim near or wade in marshy areas where snails are commonly found.

• Towel dry or shower immediately after leaving the water.

• Do not attract birds (e.g., by feeding them) to areas where people are swimming.

• Encourage health officials to post signs on shorelines where swimmer’s itch is a current problem.

For questions about Whiskeytown’s water quality monitoring program, email us at [e-mail].

 

A park resource management specialist reaching into the water to test water quality at Brandy Creek Beach. Frequent water testing at swim beaches makes sure that Whiskeytown's waters stay clean and clear.