CEE 371 Fall 2009

Homework #1   Water Demands and Population Projections

Table 1 contains water demand and population data for Amherst, Massachusetts.  This data is to be used in answering the questions for this assignment.  This is an individual assignment

Table 1. Average Daily, Maximum Daily & Peak Hourly Demands, and Population for Amherst, MA, 1960 -2000

# Year

Annual Average Daily

Demand

(MGD)

Maximum Daily Demand

(MGD)

Peak Hourly Demand

(MGD)

Population

1960

1.34

1.91

3.62

13,718

1970

2.90

4.25

7.25

26,331

1980

3.19

4.24

9.57

33,229

1985

3.73

4.75

9.24

34,537

1990

3.95

5.27

9.85

35,228

1995

3.97

5.43

10.4

35,065

2000

4.15

5.81

10.1

34,874

1.      Prepare a figure showing the average daily and maximum daily water demand data provided in Table 1 Put two plots on the same figure; one plot showing average daily demand and the other showing maximum daily demand.  Use units of MGD for the demands with a scale from 0 to 8 MGD, and the time scale should go from 1950 to 2030.  Based on the plots (no calculations), what is your estimate of the average daily and maximum daily demands for 2010 and 2020?

2.      Prepare a figure with two plots showing the ratios of maximum to average daily demand and of peak hourly to average daily demand using all the available data in Table 1. Plot these ratios (scale: 0 to 4.0) versus year (scale: 1950 to 2010).  Compute the minimum, maximum, and mean value for each ratio and compare the mean values to the national averages presented in class.

3.      Using population data and Amherst water demand data from Table 1, compute the minimum, maximum, and mean for the average daily per capita demand in gpcd.  Prepare a figure plotting average daily per capita demand (scale of 80 to 120 gpcd) versus year (scale of 1950 to 2010).  Compare the mean value to the U.S. national average presented in class.

4.      Using the historical population data for Amherst in Table 1, make population projections for 2010 and 2020 using the linear growth mathematical model and one other mathematical model.  Give reasons for the second type of model that you choose.  Clearly explain your approach and state all assumptions.

5.      Using your population projections from part “4”, calculate the average daily and maximum daily demands (in MGD) for 2010 and 2020.  Select an average per capita daily demand value and a ratio of maximum daily to average daily demand based on your analysis of the Amherst data from parts “2” and “3” above; indicate why you chose the value of each parameter.

6.      Calculate the fire demand needed for Amherst for 2020 using your population projections from part “4”. Express answers in units of gpm and MGD.

Assigned: 16 Sept 09

Due: 23 Sept 09