The Timnath Reservoir is an active reservoir that is used by the New Cache La Poudre Irrigation Company (CLP) for irrigation purposes. The Town leases the recreational and surface use rights to the reservoir for the benefit and enjoyment of the Town’s residents. Every year the CLP distributes water from Timnath Reservoir to their water shareholders for agriculture purposes.

Those shareholders own the water in the reservoir and rely upon that water to irrigate their farms. Each year, around the beginning of July, this distribution of water commences and continues for the remainder of the growing season. The amount of water distributed depends upon the demand, the amount of rainfall, and the amount of water available in the basin.

2020 is shaping up to be a year where the distribution of water may be significant. You will start to see the water levels dropping in the reservoir due to this situation. The use of the reservoir will continue, however, new hazards may present themselves. Nontoxic floating algal mats (comprised of filamentous green algae) may begin to appear near the shore. The shoreline will begin to move outward exposing potential hazards that were once below the water’s surface, including areas where rooted aquatic plants may interfere with boat operations. Portions of the reservoir that were under several feet of water may now be exposed including the dock and ramps, which will start to become more exposed and less accessible. There may be a point in time where the dock will be unusable, and the ramps will be fully exposed and also unusable.

This will be a progression over several weeks depending on weather and the amount of water being released from the reservoir. Please be aware of these conditions and be extra vigilant while using the reservoir to avoid these hazards.

In addition to the declining water levels, there is another concern that presents itself this time of year. That concern is the presence of blue-green algae. Blue-green algae can come in various types. Some types may be toxic to humans and animals if you come into contact or ingest it. Symptoms may include diarrhea, vomiting, abdominal pain, allergic reactions, respiratory issues, eye and skin irritation and rashes. Certain types of blue-green algae have also been known to cause death to pets and livestock if ingested. The Town samples and analyzes the water for the presence of blue-green algae and conducts further testing to determine if it is toxic. Blue green algae forms when the weather is warm. Each July the reservoir sees a rise in blue-green algae that may persist for several weeks until weather conditions change.

2020 conditions suggest that blue-green algae will begin to present itself. The Town is closely monitoring the water for the potential presence and health risks associated with coming into contact with the blue-green algae. The Town has not yet determined that the toxic variety of blue-green algae is present in the reservoir since those tests take additional time to complete. However, in an abundance of caution, the Town is notifying reservoir users that toxic blue-green algae could be present and to use caution while using the reservoir.

If you see algae on the surface of the water, it is advised that you avoid contact with it and that you do not allow pets to drink or enter into the water. If, after being in the reservoir, you or your animals have sudden or unexplained sickness call you doctor or veterinarian. As additional testing is completed, and as new or different information is acquired by the Town, that information will be distributed through similar means.

People often ask about the treatment options for the blue green algae within the reservoir. Treatment options have been explored in the past, however since the primary use of the reservoir is agricultural and not for consumption and the reservoir is so large in size, the cost of treatment is prohibitive.

We’ve also received questions about retaining the water for recreational use throughout the season. Since the Town does not own the actual water, this is not feasible.

Thank you for your understanding regarding this dynamic situation.