Assessing Cumulative and Secondary Point and Non-Point Pollution Sources at Jobos Bay Watershed

Basic Project Information:

Problem and Research Objectives

The Jobos Bay National Estuarine Research Reserve (JBNERR) is located in the south oast of Puerto Rico. Most of the land north to the reserve is devoted to the agriculture, although there is a high demand fot udban and industrial development. Surface runof and groundwater flow is toward the seachore, where the reserve is located. Changes in the land use, irrigation methods,and the increase in groundwater extraction, due to industrial and urban development, represent a serious threat to the overall water supply and water quality of the area. For this reason, JBNERR needs a tool to assess and manage there types of problems.
The U.S. Environmental Protection Agency developed a computer software package to perform watershed water quality based studies. The Better Assessment Science Integrating Point and Nonpoint Sources, BASINS, is a multipurpose environmental analysis system that deals with data storage and data manipulation when working with pooint and nonpoint source pollution.

• Facilitate examination of environmental information
• Provide an integrated watershed and modeling framework
• Support analysis of point and nonpoint source management alternatives

The use of BASINS in JBNERR will provide a useful tool for assessing and ebvaluating the impact of land use changes (urbanization, agricultural practies, et.) within the watershed. One drawback is that the required database is not urrently available in Puerto Rico. The data needs to be collected form different sources and onverted into the BASINS format so the model can be applied.

There are three main objectives to this project. The achievement of the objectives will allow JBNERR's tehnical staff to use BASINS as a watershed management tool to assess specific agricultural practices and proposed urban development over the quality of the waters reaching the reserve area.
These objectives are:

• Develop the database required by BASINS and document it's development so other users can benefit from this effort.
• Adapt the BASINS program package to JBNERR.
• Assess the point and nonpoint sources of specific pollutants within the watershed.

Methodology

First ther required data and format for BASINS was identified, and an internet search was done for the data available. The data was downloaded and stored locally. For the data nbot available online, potential sources of data were contacted, including key government agency personnel.
All collected data was converted into the required format as follows:

Hardcopy Data:
• Maps: Hardcopy maps were digitized into GIS format using a digitizing table.
Tables: Hardcopy tables were converted into dBase format so they ould be joined to GIS files. The tables were scanned and converted into a digital file using optical character recongnition (OCR) software.
Digital Data:
• GIS files were convertedto a common map prejetion in the ARC overage or ARC shape GIS file format. THe progectuion used was State Plane NAD 27. The changes in coordinates were done using ERDAS IMAGIN 8.4 and the ArcView projetion utility.
• Spreadheets and other digital tables were converted into the dBase file format so they could be joined or assoiated to the GIS files.