1. Urban Watershed Delineation: Incorporation of Storm Sewer Networks James Bornemann Undergraduate Student Dept. of Geodesy and Geomatics Engineering University of New Brunswick

2. 2 of 17 Background Fredericton Area Watersheds Association (FAWA) Community based monitoring and research City of Fredericton Population ~ 50,000 Environmental management by watershed Socioeconomic and biophysical conditions Need: Accurate watershed boundaries

3. 3 of 17 The City of Fredericton

4. 4 of 17 Social Ecological Conditions

5. 5 of 17 Previous Delineations New Brunswick DELG small scale delineation Wade MacNutt Local scale Combined automatic and manual method

6. 6 of 17 Storm Sewer Networks Are storm sewer networks significant to watershed delineations? Historical Evidence Ditch to divert headwaters of the swamp ~155 acres for development Unknown location of early pipes Size vs. land use of area

7. 7 of 17 Historic Map – The Swamp

8. 8 of 17 Watershed Delineation Methodology Digital Terrain Model Based on Digital Terrain Model (DTM) Analyze topological relationships to model hydrological processes Assumption: Surface Flow Only

9. 9 of 17 Topographical Watershed Delineation Filled DTMFlow DirectionAccumulation Grid Generated StreamsIdentify OutletsWatershed Delineation

10. 10 of 17 Storm Sewer Delineation Other Considerations Roads Other Drainage Networks Delineate Catch Basin WatershedsIdentify Storm Sewer Network Final Delineation

11. 11 of 17 Watershed Comparison

12. 12 of 17 Types of Watersheds 3 Types of Watersheds: Urban-Topographic Composite Shared Maps of the 3 types

13. 13 of 17 Accuracy Process vs. Accuracy Precision of elevation data +/- 10 ft. Vertical <100 ft. Spacing of Elevation Data

14. 14 of 17 Environmental Management Application Require good information to make good management decisions Overlay watersheds and land use to help determine cause and affect Corbett Brook Watershed Management Example…

15. 15 of 17 Corbett Brook Land Use

16. 16 of 17 Summary Methodology for delineating urban watersheds with storm sewer networks Storm sewer networks can significantly alter watershed boundaries Accuracy must be considered Land use of additional area can be as important as the increase in area

17. 17 of 17 Questions? Contact: James Bornemann, d191d@unb.ca