Yes, Virginia, there is a water quality model. But don't think of it as some sort of Santa Claus that's going to give you everything you wish for, or you may be in for a big disappointment.

This is the message I tried to get across when I spoke to a large gathering of Virginians gathered together by the James River Association recently to help develop a tributary strategy for nutrients in the James. Similar groups are meeting to discuss all the rivers south of the Po-tomac, which are required to have strategies in place by certain dates under Commonwealth law.

Back in 1992, when all of the Bay Program partners agreed to using tributary strategies to meet our nutrient re-duction goals, a model run was completed which divided the inflows of all the rivers of the Chesapeake into three groups.

As a group, the rivers below the Potomac seemed to have minimal effects on oxygen deficiencies and other problems in the mainstem of the Bay. So it was decided to set as an interim goal the 40 percent reduction (from 1985 to 2000) being used in other rivers, and to use the next generation of the water quality model to help set permanent goals in these Virginia rivers at a level needed to support and restore the living resources in their own tidal portions. These tidal river segments in Virginia are not small potatoes; the James, for example, has a tidal area equivalent to the Chesapeake above Baltimore!

Some progress has been made toward the interim goal of a 40 percent reduction in controllable loads (controllable was defined in 1992 as point and nonpoint sources, but did not include air and other sources we now know are, in fact, capable of being reduced). Phosphorous from the James was to be reduced from 6.5 million pounds per year to 4.0 million; the level of 4.2 million pounds had already been reached by 1996, and the 2000 estimate is 4.1 million pounds. Progress with nitrogen has not been as impressive.

The reduction from 1985-2000 is to be from 44 million pounds per year to 30 million pounds; by 1996, 40 million pounds had been reached, but the estimate for 2000 is still 36 million pounds.

But 40 percent is an interim goal until one more appropriate for the recovery of the James and other rivers can be set. And that's become the basis for a lot of discussion because the James appears to raise a number of special issues. Its tidal and current interactions with the Bay and the Atlantic Ocean are very complex and much of its lower estuary is subject to turbulence. Because of this and other reasons, sediment may be a more important factor than nutrients in some parts of the James system.

Dis-solved oxygen and benthos do not seem to be as reduced as in other rivers, and there is not an evident summer oxygen deficiency problem. So the James ex-hibits some unique conditions which support the idea of goals that might be different from other Chesapeake tributaries in both degree and character.

A number of people seem to be relying on the new model to settle these issues. But a model is merely a tool to test options. If those options have been worked out ahead of time, it can help. If folks think that it will plunk out an answer like 37 percent for nitrogen, or 42 percent for phosphorous, or 50 percent for sediment, they are going to be disappointed.

The new model will be the best estuarine water quality model on earth; it will tell us the effects of loadings from the James on water quality, oxygen and living resources like grasses and bottom-dwelling benthos in its tidal portions. But that means nothing if there is not agreement on the living resource response Virginians want to see, or if there is no consensus on how to control the various sources of the loadings.

So, we need to develop a list: "What to do while the model is coming." First, Virginians must decide what they want to be the habitat and living resource goals for the James and other rivers. They need to draw upon the vast store of historic information about what was there before - the oyster reefs, the grass beds, etc. They need to use the concentration of top estuarine scientists in Virginia's universities to reach consensus on the living resource focus of the recovery of the river. The model is useless unless it can report how close a given set of actions upstream will come to an agreed upon resource response.

Second, there must be a more sophisticated look at the interactions of the James with the Bay and the ocean. This will be aided by the early availability of the hydrodynamics portion of the model this winter, several months in advance of the full model coming on line. We plan to carry out a set of "tracer runs" that will give Virginians a much more detailed understanding of just how much the influx of the Bay and the ocean affects the tidal James and vice versa.

Third, there must be a focus on real and perceived enrichment issues and the sources of the problems. A better understanding of all sources and their relative contributions, including nitrogen from the air, will provide the basis for defining logical and supportable reduction scenarios.

Fourth, there must be a concerted effort to identify and resolve potential "roadblock issues" now. For example, getting to the bottom of the nutrients vs. sediment issue with the best available science as soon as possible is the key to working out the role that wastewater treatment plants will play in the strategy.

If it is decided that sediments rather than nutrients should be the focus, then the point sources will have substantially less to do. If nutrients are the key, point sources are a cost-effective solution with immediate results and the cost spread over a large number of individuals. The model will not help on this issue; in fact, if the debate is not resolved early on by the science, the model will then become part of the argument and a target for some to discredit. That will help no one.

Fifth, the management options for loadings reductions need to be identified before the model is ready. That way, the model can be used to test the various scenarios which have been put together. If you wait for the model to identify the scenarios for you, the result will be failure, because everyone will spend their time arguing over what should be in the data input decks. We all know about "garbage in, garbage out"; if there is not agreement on the practicality and feasibility of the options being loaded into the watershed model to feed into the water quality model, then folks will focus on finding the garbage rather than the solutions.

Sixth, once identified, the scenarios for loadings need to be narrowed to a few which can set the parameters for action and can test a couple of options within the range. There is neither time nor money to run dozens of scenarios through the model, so the options need to be shaken down to a realistic number.

These are all things that not only can be done while waiting for the model - currently scheduled to go operational in the spring - they must be done if the model is to be of any value to Virginians. A final thought: We should not be alarmed by the imperfect knowledge we have at this stage. In the words of Sir Francis Bacon, who was at his height during the reign of the very King James after whom the River was named, "If a man can begin with certainties, he shall end in doubts. But if he will be content to begin with doubts, he shall end in certainties."

There are no easy answers here, certainly not if we hope to rely on a model to do our thinking for us. But we can use the model to help us turn our knowledge and our doubts into goals with the requisite certainty for the James and its sister rivers.