THE SANDERSON PROJECTFinding the S vs. Q relationshipBy: Cody Hudson

SITES Background Water Resources “Site”

Analysis Program Developed for NRCS Performs hydrologic

and hydraulic analyses of water control structures

Calculates spillway stability

Single Event Analysis Used to simulate

design storm through existing structures

Calculates Inflow HydrographOutflow HydrographSpillway StabilityStorage/Outflow

Hydrology (Inflow)

Enter Rainfall or Hydrograph

Calculate SCS Hydrograph based on Basin characteristicsRainfall amountRainfall distribution

Elevation-Storage

E(S)=Elevation function of storage

dE(S)

Hydraulics(Outflow) Principal Spillway

Orifice flowWeir flow

L

WD

Hydraulics(Outflow) Auxiliary Spillway

Open Channel FlowWidthSide SlopeChannel SlopeLengthManning’s n

2/13/2 SARnkQ

Watershed Schematic

Structure

Reach

UncontrolledSubwatershed

Junction

Sites ModeloCN=60o6hr 100 year rainfall = 5.11 inoPeak Flow = 10,323 cfs @ 8.6 hr

Sites ModeloCN=74o6hr 100 year rainfall = 5.11 inoPeak Flow = 18590 cfs @ 6.5 hr

Site 11

Questions