Lake Angelo
Lake Angelo is a sandy-bottomed 'ridge' type lake with somewhat good to fair water quality for a lake of this type. Lakewatch data indicate that there has been somewhat of a decline in water quality since 1996. Nutrient levels, particularly phosphorus, have increased, resulting in an increase in algae concentrations and therefore a decrease in water clarity. Phosphorus levels are within an acceptable range for a ridge lake, ranging from 8 to 33 ppb (parts per billion) and averaging 18 ppb. Nitrogen levels range from low to somewhat high for a ridge lake, with values from 380 to 1370 ppb, averaging 780 ppb. Typical nitrogen values for a ridge lake range from 400 to 800 ppb N. Nitrogen levels in Lake Angelo appear to fluctuate naturally and do not show as much increase in recent years, unlike phosphorus - which now has almost double the concentration of P found in lake water in 1996-1999. Algae levels, as measured by chlorophyll concentration, show a general increase since 1999, probably due to the increase in P concentration. Chlorophyll levels range from 3 to 66 ppb, averaging 12 ppb. There was an algae bloom (dramatic increase in algae compared to 'normal' lake levels) in July of 1998 and another bloom in the summer of 2001. Occasional blooms are expected in lakes. However, algae levels have also approximately doubled since 1999 and nutrient levels appear to be increasing, even though concentrations are still typical of a ridge lake. Water clarity, as measured by the depth to which a standardized 'secchi' disc can be seen when lowered into the water, has declined as algae levels have increased. Secchi depths range from 2 to 12 feet and average 7 feet. However, water clarity has declined by about half since 1999. Lake Angelo is still in relatively good condition, but water quality is deteriorating and further investigation may be necessary. Click here to view water quality graphs by year.