standard_description: Construct a function to model a linear relationship between two quantities. Determine the rate of change and initial value of the function from a description of a relationship or from two (x, y) values, including reading these from a table or from a graph. Interpret the rate of change and initial value of a linear function in terms of the situation it models, and in terms of its graph or a table of values.
problem_activity: Task
California is in the fifth year of a drought. Towns have been asked to decrease water use across the state. The graph below shows the water storage in Lake Sonoma, a reservoir in Northern California from 1988, shortly after it was first filled, until February 1, 2015.
What questions do you have looking at the graph?
Describe some of the features of the graph.
What might explain these features?  (Consider data collection, weather events and reservoir management decisions.)
Based on the given information, should the region that depends on Lake Sonoma for water use implement additional water conservation measures?
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aligns: no