Dr. Martin T. AuerMichigan Tech

Department of Civil & Environmental Engineering

SurfaceWater Supply

Taking it for granted …Part I

Taking it for granted …Part II

Water Supply &The Hydrologic Cycle

Units = 1012 m3 per year

1 “1012 m3 per year” = 1 Lake Superior per year

… water. We got it.

Drinking Water Sources

Approximately two-thirds of the population of the U.S. receives its supply from surface waters. However, the number of communities supplied by groundwater is four times that supplied by surface water. This is because large cities are typically supplied by surface waters and smaller communities use groundwater.

Kankakee River Basin

The Hydrograph

Dis

char

ge

Time

DirectRunoffHydrograph

BaseFlow

Surface Water Supplies

Lakes

Rivers

Reservoirs

… now you see it … now you don’t

Supply This!

Reservoir Designby the Rippl Method

1976Flow Demand DS SDS

Month (cfs) (cfs) (ft3) (ft3)

J 69 60 2.52E+07 0.0F 128 60 1.65E+08 0.0M 117 60 1.53E+08 0.0A 134 60 1.92E+08 0.0M 120 60 1.61E+08 0.0J 66 60 1.58E+07 0.0J 39 60 -5.60E+07 -5.60E+07A 36 60 -6.43E+07 -1.20E+08S 114 60 1.40E+08 1.97E+07O 283 60 5.97E+08 0.0N 152 60 2.38E+08 0.0D 131 60 1.90E+08 0.0

annual requirement = 1.2x108 ft3

in out

dS= Q -Q

dt

Reservoir Designby the Rippl Method

0.0E+00

5.0E+07

1.0E+08

1.5E+08

2.0E+08

2.5E+08

3.0E+08

3.5E+08

4.0E+08

An

nu

al R

eq

uir

em

en

t (c

ub

ic f

ee

t)

0.0E+00

1.0E+08

2.0E+08

3.0E+08

4.0E+08

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Re

se

rvo

ir V

olu

me

(c

ub

ic f

ee

t)

Probability of Meeting Annual Requirement

Water Use Restrictions