Peace and Myakka River Water Quality Summary 2002 - Southwest ...

More documents

Recommendations

Info

The largest estimated flow-adjusted loads of TSS were observed at the followingstations:• Saddle Creek at Structure P-11 (1998, 1999, 2000)• Peace River at Bartow (1999, 2000)WATER QUALITY IN TIDAL (ESTUARINE) AREASBetween January 1993 and December 2000, as part of a larger Charlotte Harbormonitoring program, the District conducted monthly water quality monitoring at sevensites in the tidal reaches of the Peace and Myakka rivers. The sites were located atgeographic coordinates which were at or near locations that had been sampled by theU.S. Geological Survey (USGS) in an earlier monitoring program conducted during the1980s.Near-Surface SalinityThe most upstream stations in both river systems (CH-001 in the tidal Myakka and CH-029 in the tidal Peace) were located in oligohaline areas, with median salinities 20 ppt).Median near-surface salinities at the remaining stations were generally mesohaline,ranging between 10 and 25 ppt. Stations CH-002 (Myakka) and CH-004 (Peace)exhibited similar median values, of between 10 and 22 ppt. Stations CH-02B (Myakka)and CH-05B also exhibited similar median values, between 13 and 24 ppt. Highestmedian salinities (18–26 ppt) occurred at station CH-005, near the mouth of the PeaceRiver.Near-Surface ColorNatural water color, produced as a result of decomposition of leaf litter and otherrefractory organic matter, is known to be an important source of light attenuation in thePeace and Myakka river systems and portions of Charlotte Harbor.Among the stations sampled during water years 1994-2000, median near-surface colorlevels varied inversely with median near-surface salinities. Color levels were quite highat the most upstream stations, fell by about 50% between those stations and the nextdownstream sampling locations, and declined another 20-40% at the highest-salinitystations.Color levels in estuaries are affected by a variety of physical and chemical processes.The simplest physical process is dilution, which occurs when highly colored river watermixes with sea water containing much lower concentrations of the dissolved andcolloidal humic acids and other compounds that contribute to water color. Humicmaterials are also removed from the water column through two physical-chemicalprocesses — flocculation and adsorption — whose rates increase when the materialsx
are transported from fresh to more saline waters. In estuaries, flocculation of humicacid colloids reportedly occurs preferentially at salinities between 0 and 5 ppt.Median color values for Florida rivers and estuaries, as reported by Friedemann andHand (1989) based on a survey of several thousand records retrieved from the U.S.EPA STORET database, are 70.0 and 20.0 pcu, respectively. Values observed in thetidal reaches of the Peace and Myakka river systems during water years 1994-2000were substantially higher than these statewide medians.Dissolved OxygenAnnual median dissolved oxygen concentrations varied over a relatively narrow range,between about 5.7 and 7.7 mg/L. Concentrations in the “stressful” (< 4 mg/L) rangewere recorded at least once during most years at every site. Concentrations in the“hypoxic” (< 2 mg/L) range, which are potentially fatal to organisms that cannot move toareas of higher oxygen availability, were observed at the following stations:• CH-02B (water years 1995, 1999, 2000)• CH-004 (all years)• CH-05B (1994, 1995, 1998, 1999)• CH-005 (all years)Chlorophyll-aChlorophyll-a concentrations, which provide estimates of phytoplankton biomass in thewater column, are helpful indicators of a waterbody’s trophic state. Annual medianconcentrations ranged between1.0 µg/L and 13 µg/L at the tidal Myakka River stationsand between 2.3 and 10.6 µg/L in the tidal Peace River. The statewide medianchlorophyll-a concentration for Florida estuaries, as reported by an FDEP surveyconducted in the mid-1980’s, is 8.5 µg/L.Algal blooms (indicated by chlorophyll-a concentrations > 20 µg/L) occurred at everyPeace and Myakka River station at some time during the monitoring period.Pronounced blooms, with chlorophyll concentrations > 50 µg/L, were observed at threesites.Annual mean chlorophyll-a concentrations observed at several stations during wateryears 1994-2000 exceeded 11 µg/L, a value that has been adopted by the State ofFlorida as indicating potentially impaired water quality conditions in the State’s estuarinewaters. Stations and years where the annual mean exceeded the 11 µg/L ‘impairment’level included:• Myakka River site CH-002 (water years 1995, 1999)• Myakka River site CH-02B (1995, 1998, 1999)• Peace River site CH-029 (1995, 1996)• Peace River site CH-004 (1994, 1995, 1996, 1999)• Peace River site CH-05B (1999)• Peace River site CH-005 (1994).xi
Page 1 and 2: Peace and Myakka RiverWater Quality
Page 3 and 4: CONTENTSExecutive Summary .........
Page 5 and 6: REPORT ORGANIZATION AND SCOPEThe pr
Page 7 and 8: “Good” water quality conditions
Page 9 and 10: The primary manmade influences incl
Page 11: Yields of total suspended solids (T
Page 15 and 16: LIST OF FIGURESFigure 1. Map showin
Page 17 and 18: 1.0 INTRODUCTION1.1 BACKGROUNDDurin
Page 19 and 20: maintaining water quality at levels
Page 21 and 22: on the initial day of field work; t
Page 23 and 24: Figure 1. Locations of USGS gaging
Page 25 and 26: ANNUAL RAINFALLANNUAL STREAMFLOW% O
Page 27 and 28: For this study, annual average WQI
Page 29 and 30: • Big Slough Canal near Myakka Ci
Page 31 and 32: Table 2. Annual WQI values for non-
Page 33 and 34: Peace River at Zolfo Springs (USGS
Page 35 and 36: Horse Creek near Myakka Head (USGS
Page 37 and 38: Myakka River near Sarasota (USGS ga
Page 39 and 40: 3.0 CONSTITUENT LOADS AND YIELDSEst
Page 41 and 42: Table 3. Estimated annual TN loads
Page 43 and 44: Table 5. Estimated annual NO 2+3 -N
Page 45 and 46: Table 7. Estimated annual TP loads
Page 47 and 48: Table 9. Estimated annual TSS loads
Page 49 and 50: Myakka City gaging station (in wate
Page 51 and 52: PEA CE CREEK CANAL nr WAHNETASADDLE
Page 53 and 54: PEACE CREEK CANAL nr WAHNETASADDLE
Page 63 and 64:
PEACE CREEK CANAL nr WAHNETASADDLE
Page 65 and 66:
PEACE CREEK CANAL nr WAHNETASADDLE
Page 67 and 68:
###TidalMyakkaRiverTidalPeaceRiverS
Page 69 and 70:
Median color values for Florida riv
Page 71 and 72:
ecorded at least once during most y
Page 73 and 74:
5.0 REFERENCESCanfield, D., and M.
Page 75 and 76:
Water Quality Conditionsand Polluta
Page 77 and 78:
TURBIDITY (NTU), BY STATION AND WAT
Page 79 and 80:
TURBIDITY, BY STATION AND WATER YEA
Page 81 and 82:
TSS, BY STATION AND WATER YEARGAGE_
Page 83 and 84:
COLOR (PCU), BY STATION AND WATERGA
Page 85 and 86:
COLOR, BY STATION AND WATER YEARGAG
Page 87 and 88:
pH, BY STATION AND WATER YEARGAGE_N
Page 89 and 90:
SPEC. COND. (uS/CM), BY STATION AND
Page 91 and 92:
SPEC. COND., BY STATION AND WATER Y
Page 93 and 94:
DO, BY STATION AND WATER YEARGAGE_N
Page 95 and 96:
CHLA [MONOCHROMATIC, uG/L], BY STAT
Page 97 and 98:
CHLA [MONOCHROMATIC], BY STATION AN
Page 99 and 100:
NH4-N, BY STATION AND WATER YEARGAG
Page 101 and 102:
NO23-N (MG N/L), BY STATION AND WAT
Page 103 and 104:
NO23-N, BY STATION AND WATER YEARGA
Page 105 and 106:
TKN, BY STATION AND WATER YEARGAGE_
Page 107 and 108:
PO4-P (MG P/L), BY STATION AND WATE
Page 109 and 110:
PO4-P, BY STATION AND WATER YEARGAG
Page 111 and 112:
TP, BY STATION AND WATER YEARGAGE_N
Page 113 and 114:
TOC (MG/L), BY STATION AND YEARGAGE
Page 115 and 116:
TOC, BY STATION AND YEARGAGE_NUM WY
Page 117 and 118:
Near-surface salinity (ppt)SITE WY
Page 119 and 120:
Near-surface salinity (ppt)SITE WY
Page 121 and 122:
Near-surface color (PCU)SITE WY N M
Page 123 and 124:
Near-surface TSS (mg/L)SITE WY N Mi
Page 125 and 126:
Near-surface TSS (mg/L)SITE WY N Mi
Page 127 and 128:
Near-surface turbidity (NTU)SITE WY
Page 129 and 130:
Secchi depth (m)SITE WY N Minimum 2
Page 131 and 132:
Secchi depth (m)SITE WY N Minimum 2
Page 133 and 134:
Near-surface pHSITE WY N Minimum 25
Page 135 and 136:
DO (mg/L) - all depthsSITE WY N Min
Page 137 and 138:
DO (mg/L) - all depthsSITE WY N Min
Page 139 and 140:
Near-surface PO 4 —P (mg P/L)SITE
Page 141 and 142:
Near-surface DIN (mg N/L)SITE WY N
Page 143 and 144:
Near-surface DIN (mg N/L)SITE WY N
Page 145 and 146:
Near-surface chlorophyll-a (µg/L)S
show all

Peace and Myakka River Water Quality Summary 2002 - Southwest ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?