Water Quality Analysis 1999 vs. 2004-2006 (3 year average)

                                                                             

 

PHOSPHORUS

 

Elevated levels of phosphorus stimulate algal growth in lakes and streams and often lead to undesirable conditions.               High levels of algae can lower oxygen levels in lakes/streams and cause a loss of aquatic life, high levels can also cause toxins to form in water resulting in death to animals that ingest the contaminated water.

Phosphorus levels in the Hawk Creek Watershed have seen      dramatic reductions since the implementation of Best Management Practices (BMPs). 

The main stem of Hawk Creek still needs some work on reducing phosphorus levels. The Chetomba Creek and West Fork Beaver Creek subwatersheds are close to the target level of set by the Pollution Control Agency. 

The main contributors of Phosphorus are point sources (municipal and industrial discharges) and non-point sources (runoff from agricultural land and urban areas).

 

      

TOTAL SUSPENDED SOLIDS

 

Total Suspended Solids (TSS) refers to the amount of sediment/soil present in the water column.  This is also called Turbidity. The greater the amount of TSS in the water, the murkier it appears. This reduces the amount of light and can harm aquatic species and favors algae growth.  TSS can also inhibit recreation potential for swimming, boating and other activities.

Hawk Creek has seen a substantial decrease in the amount of TSS in the streams.  The average concentration standard set by the Minnesota Pollution Control Agency is 58 mg/L for the Hawk Creek eco-region.       

 

As of 1999 the TSS average for the whole watershed was 204 mg/L.  This is 3 times higher then the standard.  Due to the efforts and cooperation of landowners in the watershed from 2004 through 2006 the 3 year average was 66 mg/L. 

          

                                                                                    

                               NITROGEN

 

The most common form of nitrogen is nitrate.   Excessive levels of nitrogen can stimulate algal growth in lakes and streams. In addition to algae growth, nitrogen can cause  methemoglobinemia, or blue-baby syndrome.  Nitrogen is also thought to be the main cause of the  hypoxia zone in the Gulf of Mexico.

Nitrogen concentrations vary across Hawk Creek; in 1999 the concentrations were fairly stable except the Chetomba Creek subwatershed where the concentrations were 10 mg/L. Since 1999 the concentrations have increased. 

 

The subwatersheds shown in yellow and orange have exceeded the 10 mg/L standard for drinking water, and the red subwatershed is exceeding 15 mg/L. 

 

 

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