Update to the 1992 Dry Creek Watershed Flood Control Plan CESI/RBF RR/KM

Dry Creek Watershed Study Update Technical Analysis Status Calibration Analysis Complete 6 Storm Centering Locations Selected which generate peak flows for 12 key locations within the watershed. Base Predictive Models have been run (1992, Current and Future) …Issues with PDP and SWMM

Dry Creek Watershed Study Update Technical Analysis Status Calibration:

Dry Creek Watershed Study Update Technical Analysis Status Base Model “100-year Current” Results:

Dry Creek Watershed Study Update Technical Analysis Status Looked into Precipitation Generation Logic and found some anomalies: –PDP Spatial Adjustment Inverted Hyetograph –PDP interpolation (Log-Log should be numeric- log) –Raw Precipitation Values published in SWMM

Dry Creek Watershed Study Update Technical Analysis Status PDP Spatial Adjustment Inverted Hyetograph

Dry Creek Watershed Study Update Technical Analysis Status PDP Spatial Adjustment Inverted Hyetograph for Peak 1-hour

Dry Creek Watershed Study Update Technical Analysis Status PDP Spatial Adjustment Inverted Hyetograph for Peak 1-hour

Dry Creek Watershed Study Update Technical Analysis Status PDP Spatial Adjustment Inverted Hyetograph for Peak 1-hour – SOLUTION LOGIC

Dry Creek Watershed Study Update Technical Analysis Status Humps at 3 to 6-hour precipitation?

Dry Creek Watershed Study Update Technical Analysis Status Raw Precipitation Values published in SWMM

Dry Creek Watershed Study Update Technical Analysis Status Raw Precipitation Values published in SWMM

Dry Creek Watershed Study Update Technical Analysis Status Raw Precipitation Values published in SWMM

Dry Creek Watershed Study Update Technical Analysis Status Raw Precipitation Values published in SWMM

Dry Creek Watershed Study Update Technical Analysis Status Recommend: –Make changes to PDP for minimum ARF values –Make Changes to PDP to use Normalized Precipitation Value of 2.49 –Make Changes to PDP for Interpolation Issues –Make Changes to PDP for 150 foot elevation. –Republish SWMM precipitation TABLES as an Amendment to the SWMM

Dry Creek Watershed Study Update Technical Analysis Status Recommend:

CESI-RBF Tool Box Provides Technical Advantages PDP and Storm Centering: –GIS Automated Spreadsheets for Input

HEC-1/PDP/HMS Toolbox Option 2