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The water testing results have come back from Anatek Labs. I have attached an *excel spreadsheet (this is shown as an insert below) with the 2008 testing result and the 2011 results. This is the first year of the BOD test that also includes the NO3 and NO2 tests. I have also included the report from Anatek.

Based on the BOD (Biological Oxygen Demand) testing, the lake is in good health and considered very clean water given our reading of <2 mg/L. See reference below.

Biological Oxygen Demand (BOD) : BOD is typically reported as 5 day BOD and ultimate BOD at 20 C and reported as milligrams of oxygen consumed per liter (mg O/L). BOD 5 is used by regulatory agencies for monitoring wastewater treatment facilities and monitoring surface water quality. BOD is the biochemical oxygen demand of the water and it is related to the concentration of the bacterial facilitated decomposable organic material in the water. A sample with a 5 day BOD between 1 and 2 mg O/L indicates a very clean water, 3.0 to 5.0 mg O/L indicates a moderately clean water and > 5 mg O/L indicates a nearby pollution source. BOD is a laboratory test that requires a oxygen sensing meter, incubator, nitrifying inhibitors, and a source of bacteria.

I’m not trained in this field, however given the latest results and my research, I would put Diamond Lake someplace between a Oligotrophic and Mesotrophic classification leaning more toward Oligotrophic, which is very good.

Jeff – DLIA

*the image below is of the excel spreadsheet referenced in the letter:

Beaver dams are not new to Diamond Lake. Throughout the 70's and 80's, there was concern that beaver dams may be obstructing the inlet flow of water from the southwest end of the lake. In 1973, the DLIA hired Sewell & Associates to conduct a survey of the beaver area. The survey found that the beaver dams were changing the direction of the flow of water that otherwise would have been flowing into Diamond Lake. The main dam was destroyed in 1982, resulting in a flow of water into the lake at approximately 500 GPM. However in 1988, residents believed that beaver dams at Carter Creek were again obstructing the lake's water flow.

In September 2005, the DLIA began exploring the possibility that beaver dams might be obstructing the flow of water into the lake. Concern that dams may be altering water distribution prompted members Bill Miller, Debbie and John Harkness, Tom Wimpy and Steve and Laurie Petroni to visit the suspect area at the southwest end of the lake. Recent beaver activity was observed. Beavers had recently felled trees, constructed two dams, five lodges and created a pond with approximately two feet by twelve acres of water. Economic and ecological values of the Beaver have been the subject of many debates.

Beavers create habitats for other wildlife. Deer and elk frequent their ponds to eat the shrubbery that grows bushier after beavers cut trees. Water birds use the ponds as nesting areas and resting stops when migrating. Ducks and geese often nest on top of beaver lodges because they offer warmth and protection. Beaver ponds create diverse aquatic ecosystems. Beaver dams help reduce erosion in rivers and streams. Despite an appreciation for beavers and best intentions to live with them, conflicts with humans may arise.

Beaver activity can cause unwanted flooding, slow the flow of water, cause silt to build up, prevent water from flowing where it otherwise would, damage roads, trees, fences, decks, shrubs and crops.

The mere presence of beavers is often seen as a problem when, actually there may not be a problem. Control actions must be assessed fairly and objectively. Are they causing damage? Creating hardships? What type of damage or problem are they causing? If a problem exists, we must consider what would be the most appropriate and cost-effective controls. Once it is determined that a problem exists there are three control options, prevention, relocation and lethal control.

Working with beavers often gives the best results. If beavers are removed from a fertile area, others will generally move in. Allowing beavers to stay while addressing specific problems preserves the benefits from beavers. Using proven, cost-effective techniques to solve beaver problems often allows beavers and humans to live in harmony.

Beaver's legal status is protected by the WDFW. Information regarding prevention control methods and regulations can be obtained through the local wildlife office.

In the 1700's and 1800's hats made from beavers were very popular. The people who made these hats used arsenic in tanning the hides. They became ill. Thus, the phrase "Mad as a hatter" developed.