Advancing Water Resources Research and Management

Nueces River Authority:
Data Management for the Texas Clean Rivers Program
for the
Nueces River Basin and the Nueces Coastal Basins

By Rocky A. Freund
Information Systems Administrator
Nueces River Authority

Introduction

The Nueces River Authority (NRA) was created in 1935 by special act of the 44th Texas Legislature. Under supervision of the Texas Natural Resource Conservation Commission (TNRCC), NRA has broad authority to preserve, protect, and develop surface water resources including flood control, irrigation, navigation, water supply, wastewater treatment, and water quality control. It may develop parks and recreational facilities and may acquire and dispose of solid wastes. The NRA is governed by a Board of 21 directors appointed for staggered, six year terms by the Governor with the advice and consent of the Texas Senate. The NRA has two offices; the Main office is located in Uvalde, Texas, and the Coastal Bend Division is located in Corpus Christi, Texas.

The Texas Clean Rivers Program (CRP) is administered by 14 agencies under the supervision of the TNRCC. The goal of the CRP is to maintain and improve the quality of water resources within each river basin in Texas through an ongoing partnership involving the TNRCC, state agencies, river authorities, regional entities, local governments, industry, and citizen groups. The program uses a watershed management approach to identify and evaluate water quality issues, establish priorities for corrective action, and work to implement those actions.

With respect to the CRP, the NRA is responsible for the Nueces River Basin, the San Antonio - Nueces Coastal Basin, and the Nueces - Rio Grande River Basin (Figure 1) (Adobe Acrobat Format).

Surface Water Quality Data

Surface water data are collected quarterly at eight stations in the Nueces River Basin, ten in the San Antonio - Nueces Coastal Basin, and two in the Nueces - Rio Grande River Basin by the NRA. The other stations are sampled by the TNRCC. The rivers and water bodies are divided into segments, and the goal is to have at least one monitoring station per segment. The water samples are analyzed at local labs for:

Field parameters that are also measured include:

The data, both NRA's and TNRCC's, along with station location and description information, are stored in an Oracle database housed on the Texas A&M University-Corpus Christi campus.

Data Storage

The database is comprised of four primary tables. One that contains station location information, one that contains station description information, one that contains sampling event and result information, and one that contains information about the parameters that are measured.

The information stored in the station_location and station_description tables are designed as name-value pairs:

The first field, stnid, contains a station's five-digit identification number.
The second field, code, contains a single character identification code. "S" is used to indicate that a station is part of the Surface Water Quality Monitoring (SWQM) network.
The third field, param, contains a description of stored information.
The fourth field, parmval, is the value for param.

For example, the following is the information contained in the station_location and station_description tables for SWQM station 12964:

The tables are organized in this manor to optimize disk space. There is redundancy on the part of the station identifier and code, but there are no empty fields in the table. For example, if the station does not have a corresponding USGS stream flow gauge, the record with a param of "usgsid" will not exist.

The parameter table is organized in the same way, but the parameter codes (TNRCC refers to these as storet codes) are used in place of the station identification number. The code is still used to designate between surface water and wastewater parameters.

The event_result table is organized in a slightly different manner:

The first field, stnid, contains a station's five-digit identification number.
The second field, code, contains a single character identification code.
The third field, tag, contains a event identification number. This number uniquely defines a sampling event - station, time, and depth.
The fourth field, storet, is the parameter for which data are collected.
The fifth field, gtlt, contains either "=", "<", or ">". This indicates if the measured value is the actual value, or is outside of the accepted range.
The sixth field, parmval, is the measured value.

For example, the following is the information contained in the event_result table for the sampling that took place on March 08, 1999 for SWQM station 12964:

Data Access

The data are accessible to the public via the NRA's home page. The user does not have to know anything about how the database tables are structured nor any database commands. To access the data, click on "Clean Rivers Program" then "Data Access." The data access page gives the user several options as to how to retrieve information:

All stations within a specific county

All stations within a specific basin

All stations within a specific stream segment

All stations within the three basin area

As seen on the data access page, the database also includes wastewater facility and permit information, and these data are accessed in the same way.

The user retrieves a list of stations via one of the above options. This example lists all the monitoring stations in Nueces County. The same information is retreived for all four options: station identification number and station name / description. This list includes SWQM station 12964 that has been used in the previous examples. The station numbers are linked to information about that particular station.

Still using 12964 as an example, the user is able to view all the information from both the station_location and station_decription tables. The information is listed in table form with more descriptive headings than the "param" field value. The page also lists all the dates for which there are data in the event_result table. The monitoring information for March 8, 1999 is shown in table format. The first field is the value; the second field is a description of the measured parameter; the third field is TNRCC's storet code.

The data and information are extracted from the database using embedded SQL within Perl CGI scripts and output to HTML pages. All text and numeric formatting take place within the Perl scripts.

Planned Improvements

As with most web sites, the pages for the NRA and the CRP are periodically updated, modified, and improved. Three major improvements that are planned are to

1. Allow the user to request a range of dates for which to retrieve data for a given station.
2. Allow the user to request specific parameter information from multiple stations.
3. Allow the user to download the data for use in reports and / or spreadsheets.

Contact Information

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