Think about this. Suppose that if a new tax bill is passed today, the Federal budget surplus will be $100 billion next year and $400 billion the year after that. What is the effect of the tax bill on the surplus? Does the tax bill increase the surplus?
You can't say unless you know what the surplus would have been without the tax bill. If the baseline projection - with no tax bill, but all other factors considered - called for a surplus of $200 billion next year and $600 billion the year after that, then you could conclude that this tax bill reduces future surpluses (even though they are still increasing, they are not increasing as much).
Water resources planners help communities find and implement the "best" plan for managing water in the future. What's "best" is decided by comparing the expected benefits and costs of alternative plans, and scoring is based on how well the alternative compares to the baseline. The baseline starts with current conditions and continues with expected future conditions (not counting the changes the study team could instigate, which will be considered as alternatives to the baseline condition).
The baseline condition is typically not static, but it reflects only those changes that are beyond the control of the planning team. In Federal planning rules, the baseline is called the without project condition because the team is in charge of that part of the future. Wet and dry weather, population change, and changes in land use are all parts of a baseline condition that usually change over time.
In the Fairweather example, the baseline future includes increased population along with a slight reduction in per capita weather use because of a gradual shift to water conserving plumbing fixtures.
After describing the baseline, quickly go back over the work you've done previously. Are the planning objectives still appropriate? For example, if the projections are for the mill and refinery to close down, do you still want to increase the reliability of navigation channel depths? Are the constraints still appropriate, or does the baseline projection suggest that the team should develop an alternative that would relax a constraint? For example, if Fairweather is planning to spend $1 billion on a plan to reduce Total Maximum Daily Loads by 90%, is it still necessary to impose a minimum instream flow for dilution of wastewater?
Now consider the specific metrics you've chosen for evaluating the alternatives. Does the baseline condition need to be better established? For example, if one of the measures of comparison is the effect that plans will have on recreation, you may decide you need to determine if there will be an increased demand for boating in the future.
The Fairweather Baseline
In the original problem description, the regional population and growth rate were given. The baseline would encompass the following assumptions: 1) no system expansion in the future, 2) per capita water consumption remains the same, 3) water use restrictions and pricing are not planned, and 4) population increases as projected. The baseline should be fleshed out as completely as possible in terms of the metrics the team will use to compare alternatives.
As you look over the Fairweather baseline, consider what you will have to do to develop the baseline for the real problems you are faced with. List the likely components of the following inventories as well as the sources you would consult to define these components in greater detail. For example -
- Facilities Inventory
- Resource Inventory, Legal Inventory
- Management Inventory
- Policy Inventory
- Economic Inventory
- Demand Inventory
- Hydrological Data
Consider the uncertainty surrounding the future projections. Long term forecasts are never right; the question is, how much do they have to be "off" before the recommendations from the planning process would change? You must always assess this risk; the effort spent on risk assessment depends on the sensitivity of the evaluation to the uncertainties in the projections. The adversarial relationships in even the best water resources planning teams will help locate the critical uncertainties in your baseline projections.