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

• Sect. 3 Constituent Loads and Yields – provides estimates of annual loads(metric tons/year), yields (kg/ha/yr), and flow-adjusted loads (kg/L) of selectedwater quality constituents using data collected at the non-tidal monitoring stationsduring water years 1998 – 2001;• Sect. 4 Water Quality at Tidal Stations – summarizes monthly water qualitydata collected by the District in the tidal reaches of the Peace and Myakka riversduring water years 1994 – 2000.2.0 WATER QUALITY AT NON-TIDAL STATIONS2.1 METHODSIn order to characterize current water quality conditions, monthly monitoring wasconducted at a number of sites in the Peace and Myakka River basins during wateryears 1998, 1999, 2000, 2001 (Table 1).The water quality monitoring stations were co-located with long-term USGS streamgaging stations (Fig. 1). At each gaging station the USGS collects continuous recordsof stream stage, makes periodic measurements of stream discharge throughout a rangeof stages, and computes an estimate of daily mean stream discharge based on thecontinuous stage records and the measured stage-discharge relationship.Co-location of water quality monitoring and stream gaging stations is important for atleast three reasons (NRC 1999):• Concentrations of water quality constituents often vary with stream stage, andadequate information on both concentration and stage is needed to allow thesedynamic relationships to be documented and understood;• Records of stream discharge (volume/time) and constituent concentrations(mass/volume) are necessary for the calculation of constituent loads (mass/time),which are important indicators of the effectiveness of water quality managementefforts; and• Watershed management efforts are more likely to succeed if managers have anadequate understanding of relationships between the quantity and quality ofsurface water flows within the watershed, and relationships between thesevariables and other ecosystem components.Monthly water quality monitoring began in the Peace River watershed in October 1997,and in the Myakka River basin in October 1998. Water samples were collected bySWFWMD field staff over a three-day period during the first week of each month.Stations located in the northern portion of the Peace River basin were normally sampled4