1. Using a Digital Terrain Model to Analyze a Watershed in Order to Match Inlets with their Respective Outfalls
Aspen Navarro, Project Manager, GIS Analyst
Michael Jones, Assistant Project Manager, GIS Analyst
William Perry, Project Designer, GIS Analyst

2. Outline Purpose Scope Revised Timeline Challenges and Concerns
Remaining Task
Conclusion

3. Purpose New methodology
Watershed analysis using a digital terrain model (DTM)
-Identify where inlets fall within the watershed of specified outfall
-narrows down where pollution is coming from
Create a cartographic model for backup and reference
DTM looks at the Earths surface, excluding any objects
Why the network analysis didn’t work and what were doing now moving forward

4. Graph showing the scope of the project
Graph showing the scope of the project. West of San Antonio in Bexar county

6. Showing the problems with the underground channel
-why we changed our method

7. Revised Timeline
Major delays included data processing issues and interoperability Issues, leading to a larger amount of time spent on pre-processing and a lower time spent on analysis. Four major dates; two meetings, a progress report, and a final project on Dec 7th.
Activity
Week Date
5-Sep
12-Sep
19-Sep
26-Sep
3-Oct
10-Oct
17-Oct
24-Oct
31-Oct
7-Nov
14-Nov
21-Nov
28-Nov
5-Dec
Week Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Meeting with client ; research
Data collection; manipulation
Preprocess data
Analysis and integration
Edit; finalize
Final report
Final presentation
*Important dates
*Meeting 1
*Meeting 2
*Progress Report
*Final

8. Remaining Task
Task 1: Organize data for analysis and delineate project area
Minimize data
Use data to delineate Westside Creeks
Task 2: Watershed analysis
Fill  Flow direction  Flow accumulation  Snap pour point  Watershed
Task 3: Matching inlets with respective outfalls
Identify inlets within each outfall watershed boundary

9. Watershed Analysis Challenges and Concerns
Surface elevation will make results inaccurate
Sewer pipes do not have curves
Many of the outfalls are close together
A digital terrain model (DTM) is required for an accurate watershed analysis
Matching ALL inlets to outfalls within the timeline

10. Screenshot showing the cluster of outfalls

11. Images comparing DEM to DTM
Image on the left is the newest DEM nick provided us, image on the right is the DTM

12. Conclusion Increased accuracy of connecting inlets to outfalls
Split up workload to catch up on lost time
Moving forward with or without a DTM