METHODS AND APPROACH 

 Data Sources 



Hydrographic data for this analysis were obtained from 

 a variety of sources, including the Texas Coastal Ocean 

 Observing Network (TCOON) marine monitoring 

 system of Texas A&M University-Corpus Christi 

 Conrad Blucher Institute (CBI), the weather station 

 network administered by the National Weather Service 

 (NWS) and the national stream flow gauging program 

 conducted by the U.S. Geological Survey (USGS) 

 (Table 3-1). 



Table 3-1: SummatY of hydrographic data sources. 



surface in Nueces Bay is in response to meteorology, 

 tides and river hydrographs, this is negligible in 

 comparison to the temporal excursions in water level 

 in the river and marsh. Therefore, stage data from the 

 White Point gauge was regarded as an acceptable 

 indication of the general coincident elevation of 

 Nueces Bay. 



The USGS gauges from which data were obtained 

 included the Nueces River at Calallen (Station 

 0821 1500) (Calallen gauge) and Rincon Bayou near 

 Calallen (Station 08211503) (Rincon gauge). The 

 Calallen gauge was located on the Nueces River, about 

 0.64 km upstream from Calallen Diversion Dam 



Data Source 



Parameter 



Measurement Location 



Data Type 



Nueces River at Calallen, 

 USGS 



TCOON system, CBI 



Corpus Christi Bay NWS 



Rincon Bayou near Calallen, 

 USGS 



Estimated daily flow 



Water level 



Wind direction and velocity 



Salinity 



Daily precipitation 



Water level 

 Current velocity 

 Calculated flow 



Daily precipitation 



Nueces River 



Nueces and Corpus Christi 

 bays 



Corpus Christi International 

 Airport 



upper Rincon Bayou 



Data recorded at 

 15-minute intervals 



Data recorded as 

 6-mlnute averaged 

 values 



Data archived as daily 

 values 



Data recorded at 

 15-minute intervals 



Data archived as daily 

 values 



Data obtained from the TCOON system included 

 salimty and water level. For each of these parameters, 

 hourly measurements were obtained from the CBI data 

 archive, and, for the analysis reported here, subjected 

 to 24-hour averaging to obtain daily mean values. The 

 salinity data used were from the CBI SALT03 gauge, 

 which is situated due south of VCTiite Point in the 

 center of the bay about equidistant from the mouth of 

 Rincon Bayou and the mouth of the Nueces River 

 (Figure 3-1). This gauge responds to flow from both 

 conveyances. Salinity concentrations are measured by 

 robot conductivity sensor and converted to salinity, 

 reported in parts per thousand (ppt). 



Water level in Nueces Bay was that measured at CBI's 

 White Point gauge, nearer the mouth of Rincon Bayou. 

 While there is no doubt some slope to the water 



(Figure 3-2) and about 3.05 km upstream from the 

 entrance of the Nueces Overflow Channel. Flow data 

 were obtained from both gauges, and stage and 

 precipitation data were also obtained from the Rincon 

 gauge. There are significant limitations to the accurac)' 

 of the flow data from the Calallen gauge at higher 

 values for two primary reasons. First of all, the gauge 

 ceases to represent the total flow of the Nueces River 

 above about 56.63 cubic meters per second (m'/s) 

 (2,000 cubic feet per second (cfs)) due to activation of 

 additional flow channels in the floodplain. Second, no 

 reliable field observations of discharge values are 

 available above 77.87 m'/s (2,750 cfs), so all daily flow 

 values in excess of 77.87 m'/s (of which there were 

 3 in the record under review) were estimated by 

 extrapolation. 



3-2 



«* 



Hydrography 



