| Report Year: 2009 |
| Beaver Lake, Dallas County |
| Summary Data Table |
| Parameter | 7/13/2009 | 6/8/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 11.8 | 11.1 | 11.5 | - | - | 12.4 | 12.6 | 12.5 | 12.5 | 13.2 | 12.5 |
| Thermocline Depth (m) | 5.3 | 5.8 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 0.6 | 1.1 | 0.8 | - | - | 0.6 | 0.6 | 2.0 | 1.2 | 1.9 | 0.9 |
| Temperature(oC) | 23.7 | 19.8 | 21.7 | - | - | 23.8 | 22.2 | 22.2 | 23.9 | 24.6 | 25.2 |
| Dissolved Oxygen (mg/L) | 7.1 | 9.2 | 8.1 | - | - | 11.8 | 12.1 | 7.7 | 9.7 | 7.8 | 7.7 |
| Dissolved Oxygen Saturation (%) | 84 | 100 | 91.9 | - | - | 138.6 | 141.4 | 86.1 | 114.6 | 94.8 | 93.1 |
| Specific Conductivity (μS/cm) | 290.0 | 320.0 | 305.0 | - | - | 262.6 | 278.8 | 311.2 | 287.0 | 314.8 | 349.9 |
| Turbidity (NTU) | 9.2 | 9.3 | 9.2 | - | - | 34.4 | 48.2 | 11.4 | 13.3 | 6.0 | 11.8 |
| Chlorophyll a (μg/L) | 64.0 | 22.0 | 43.0 | - | - | 104.1 | 75.3 | 18.1 | 36.5 | 11.6 | 23.9 |
| Total Phosphorus as P (μg/L) | 92 | 57 | 75 | - | - | 92 | 110 | 81 | 66 | 65 | 162 |
| SRP as P (μg/L) | - | 1 | 1 | - | - | 1 | 25 | 1 | 4 | - | - |
| Total Nitrogen as N (mg/L) | 1.94 | 1.49 | 1.72 | - | - | 2.70 | 3.44 | 2.21 | 1.51 | 1.88 | 1.33 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 16 | 52 | 33 | - | - | 16 | 63 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 7.1 | 14.6 | 10.8 | - | - | 2.5 | 13.5 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.33 | 1.42 | 0.88 | - | - | 1.41 | 2.25 | 1.14 | 0.35 | 1.06 | 0.14 |
| TN:TP ratio | 21 | 26 | 24 | - | - | 39 | 34 | 33 | 25 | 32 | 8 |
| pH | 9.3 | 9.0 | 9.2 | - | - | 9.0 | 8.9 | 8.6 | 8.8 | 8.2 | 7.6 |
| Alkalinity as CaCO3 (mg/L) | 110 | 185 | 148 | - | - | 106 | 119 | 84 | 112 | 128 | 155 |
| Silica as Si (mg/L) | - | - | - | - | - | 3.27 | 5.24 | 2.41 | 2.46 | - | - |
| Dissolved Organic Carbon (mg/L) | 4.35 | 5.36 | 4.86 | - | - | 3.80 | 11.89 | 10.45 | 8.84 | - | - |
| Inorganic Suspended Solids (mg/L) | 6 | 3 | 4 | - | - | 7 | 7 | 2 | 5 | 3 | 8 |
| Volatile Suspended Solids (mg/L) | 11 | 11 | 11 | - | - | 29 | 11 | 5 | 7 | 2 | 5 |
| Total Suspended Solids (mg/L) | 17 | 13 | 15 | - | - | 36 | 18 | 7 | 13 | 5 | 13 |
| Carlson Trophic State Index (Secchi)* | 69 | 59 | 63 | - | - | 69 | 67 | 50 | 57 | 51 | 61 |
| Carlson Trophic State Index (Chl a)* | 71 | 61 | 67 | - | - | 76 | 73 | 59 | 66 | 55 | 62 |
| Carlson Trophic State Index (TP)* | 69 | 62 | 66 | - | - | 69 | 72 | 67 | 65 | 64 | 77 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |