REGION H WATER PLANNING GROUP MEETING
DECEMBER 1, 1999
CITY HALL, CONROE, TEXAS
MEMBERS PRESENT: James Adams, Chairman, Gary Oradat, Roosevelt Alexander, John Bartos, Robert Bruner, Judge Mark Evans, Mary Alice Gonzalez, Commissioner Jack Harris, David Jenkins, Judge Tom Manison, James Morrison, Ronald Neighbors, Ernest Rebuck, Jack Searcy, Jr., Steve Tyler, C. Harold Wallace, Kerry Whelan
PRESIDING: James Adams
Substitutes: Jimmie Schindewolf for Judge Robert Eckels, Terry Thomas for Carolyn Johnson, Jace Houston for Marvin Marcell, Skip Thomas for James Murray, Denis Qualls for Tom Ray, Carole Baker for Michael Sullivan, and Robert Stevens for Danny Vance.
APPROVE MINUTES OF NOVEMBER 3, 1999 MEETING:
Motioned by Ron Neighbors. Seconded by Alexander Roosevelt. Motion carried.
CONSULTANTS UPDATE ON WATER DEMAND:
Letters sent to Regions C and G for verification of numbers. Awaiting response to incorporate into Task II water demand table.
PRESENTATION BY GARY POWELL OF TWDB, A DETERMINATION OF FRESHWATER INFLOW NEEDS FOR GALVESTON BAY AND THE TRINITY-SAN JACINTO ESTUARY:
I am the Director of the Hydrological and Environmental Monitoring Division, which is the data collection and analysis group in Austin. We worked with the Parks and Wildlife Department, TNRCC, about 13 different parts of Texas A&M University, University of Texas, Rice
University, University of Houston, and a number of professors in collecting data and developing procedures, methods, and protocols to advance our understanding of the science of collecting physical, chemical, and biological data in these large coastal basins which are producing seafoods and fisheries.
We have gone through two legislative mandates to produce results. In the report to the Legislature, we admitted some of the critical parts of the analysis were based on unbelievable data, because it was a short-term record and possibly did not represent the bays; therefore, we had problems using those numbers for actual management purposes.
The national consensus among scientists and engineers is that you have
to have about 30 years of data in order to understand the estuary, and you see the cycles between wet periods and dry periods; and they get wet again and dry. You must understand how each of these is occurring, and what the impacts are. In the current situation, we are trying to optimize these flows by using the minimum amount of flows to achieve the maximum amount of fisheries.
The Legislature specified that we must look at the critical elements of: Sediments, nutrients, salinity gradients, biological productivity, and fisheries. So, that became a key element of our work in Texas. Biological information, inflows/salinity relationships, and inflows/production relationships, sediment, physical constraints, nutrients, nutrient cycling, these are the budgeting done for these estuaries. There is an oceanographic model that calculates circulation and salinity patterns important to the plants and animals that live in the bays. We go through an optimization procedure where we put in constraints and limits and state management objectives based on what the law says we're supposed to be doing, and we express those mathematically. We put the results into the optimization model, along with the results from other models so we have one model that is consuming the results of the other models. From that we get a feasible solution, a solution that is within the constraints and the limits and meets the objectives. We check the salinity regime and make sure that the flows are having their intended effect. If this amount of flow is achieved, the patterns of salinity and circulation created by the solution we’ve calculated match up with the actual location and zonation of the plants and animals in the system -- the brackish areas are brackish, the estuaries are estuaries, and the marine environments are more marine -- we consider the solution to be verified.
Verification is something ongoing. You never go into your future using year old numbers. You continue to monitor the physical, chemical, and biological properties of the bay. You can see if the factor management schemes are having their intended affects and if there is any mid-course corrections that are required.
The oceanographic model is for Galveston Bay. This bay has 600 nodes of one square nautical mile. The bay is roughly 600 square miles of estuary with 600 computational cells that the model runs on. One aspect of the bay that doesn't receive enough emphasis is quality. Nutrients are very important.
The inflow that we are concerned about is the shaded circle. You have to fill in the rest, along with the transfer rates, in order to figure out how many nutrients are needed to maintain a positive balance. If there is a decrease in productivity at the end of the summer for even short periods, let alone weeks or months, it can create a noticeable down-tick in the productivity. In a drought, estuaries suffer because the bay is not receiving enough water to sustain itself and will have a lower level of productivity. Nutrients are gained and lost in the system.
One of the essential parts of doing a nutrient balance is running the compartment model and summing up numbers for losses and ways in which nutrients are gained by the system. The largest amount of nutrients come into the system through combined inflow from surface drainages,
gauged rivers, ungauged bayous and creeks, wastewater, nutrients coming in on the rising tide from the Gulf through the Mississippi River or Sabine Lake, direct rainfall, nitrogen fixation, tidal export to the Gulf. Those exports are estimated with oceanographic and hydrographic models originally built to look at salinities and where fish, larvae, and eggs are transported, and how well they survive. It is also used in the nutrient analysis to budget the estuary. After looking at the long-term budget, we compute an estimated minimum budget required to maintain that estuary at 4.8 million-acre feet.
Fisheries analyses match animals up. The harvest is supposed to represent a year, but freshwater inflows are not in the same year because these animals may take three to five years to grow up. It is that grow-up period you need to know how well the fresh waters impacted them when they finally got to be adult animals and were then harvested. By the time they are adults, it takes an extreme event to affect an adult; but you can have major effects on babies. Most of the mortality is in the young of these organisms. You make a small change, a couple of percentage points in the survivability of the babies, you make a huge difference in the number of adults that turn up later. It is important that these bays have nursery areas, and nursery areas require the right salinity, food, and cover, which we estimate through our salinity and fisheries analyses.
The flow in the wintertime (January/February) is important. Many animals have negative signs on the coefficient. All of them for which that season is important that it reach statistical significance and enter the equation, all of those signs are negative. It is not true that more freshwater is always better. In fact, where there is too much freshwater in the wintertime and you have cold temperatures, and you wind up with low salinity and low temperatures, these estuarial organisms tend to have high mortality. It is too much stress. They can stand low temperature as long as the salinities are not too low. They can stand low salinity as long as the temperatures are not too low. If you have them occurring in the same season, that is bad.
May, June, July, and August have positive signs. Many organisms are relating to seasons in predictable ways, and they do not necessarily all reinforce each other. In some seasons some animals are relating positively to freshwater inflows and some are relating negatively, which means you must do some sort of management balancing, something in the analysis so that you do not artificially calculate that you are going to grow tremendous amounts of oysters and nothing else. We found our solutions by making sure the ratios of production predicted by the model for the future are the same ratios that the bay has actually produced in the past. If it produces 20 pounds of shrimp for every pound of fish, we ensure that that ratio is respected.
Salinity is set at a number of control points? The mixing zone in Trinity Bay, Red Bluff, Dollar Point, we set upper and lower bounds for salinity. As we began to look at these animals' life cycles and their chance of surviving, growing, and reproducing, it became apparent that we couldn't hit their preferences. We had to choose limits in between based on their ability to undergo all three life processes: Survival, growth, and reproduction. That means these plant and animal communities will do fine under a salinity regime that stays within those bounds.
The relationship between the amount of nutrients that feed the system and the productivity that comes out is so complicated by intervening factors that no relationship has been shown. We adjusted the scales to see if there was a relationship between harvest and nitrogen loading, not raw loading. We multiplied the amount of nitrogen coming in by the residence time, how long it would remain in the estuary before it got flushed out, and this is what we call an effective loading as opposed to raw loading. This is the way the ecosystem views that loading. When you make that calculation and you adjust those scales, you get the harvest and the nutrient loading to the system and their proximity to each other. If you have several estuaries, you can compare them.
Trinity, in the Galveston Bay system, matches up fine. Lavaca is fine. Nueces is less productive than you would expect based on the amount of nutrients it is receiving. They just completed a natural estuary program and found they had an inordinate amount of habitat destruction. The houses that the animals need to live in are not there. The sea grass beds and marshes have been lost. As a result, the system is not producing up to par. Mission Aransas estuary has the opposite problem. It is more productive than you would expect. The harvest is above where the nutrient circle is, based on the amount of nutrients being loaded into it. San Antonio Bay has no pass to the ocean. All the flows coming in go north and exit through Matagorda Bay or flow south through the Mission Aransas system. The Mission Aransas estuary is being subsidized by the next estuary, which is providing 25 to 30 percent surplus input to it. One estuary is subsidizing another one, and more important these things are related.
The cumulative flow plot adds the amount of flow that comes in each year to the previous amount of flow in the system. If the axis of the plot swings off to the lower end, you have got a trend of decreasing inflows to your estuary. If it goes to the upper side and creates a curve that indicates the system is inputting more water from another basin.
The hydrologic method says there is no relationship of increasing or decreasing freshwater inflows. Freshwater inflows to this estuary have been stable over this long term period of half a century, and the only thing that could change that in the future would be a massive change in climate or a massive change in water management practices.
A frequency analysis of those flows indicates the mean average flow at 10 million-acre feet. The mean average flow is based on dividing the total number of whatever you have got by the number of observations you have. Divide it, and you get a volume. That is the average volume that comes in. There is no time quotient in computing an average. To find the most common normal event, you calculate a median, which is a 50-percentile flow where half the flows are larger and half are smaller or a modal value, which tells you that this is the most frequent event. The difference between the average and the median is the difference between 10 and 7 million-acre feet. It is important to understand that the average may not be the correct value. It may be considered an improper measure of the central tendency, depending upon the distribution of flows. When we look at the distribution of the estuary, the median is much closer to being a proper or a correct estimate of central tendency. So, your system is not getting 10 but about 7 million-acre feet on a frequency basis. Since that is what the fish are seeing, that is good.
The other thing is how we work the problem. We had to decide on the management zone on a science policy basis what zone of the operations we were going to try to solve for, the most production you can get in a wet year, in a dry year, try to look at production in the zone we could have some impact on, which was between the median (50 percentile) and the 10 percentile as set by inner governmental agreement with the other agencies. We were looking for the amount of flow that we have to provide from our operations in our basins that would maintain these estuaries and provide good production. We can not count on extreme droughts or floods to help us. We are looking at a normal condition. In months where there is a negative relationship between flow and harvest, that number is going to be driven down. When the model hits the bottom limit, that is the 10 percentile. We did not want to predict maintenance during an extreme drought with really low flow depth; the same thing in a positive season where there is a lot of positive relationships, animals and their production and the flows coming in. The model is going to want to increase those flows to reach that maximum harvest (MaxH) and we have to cap that somewhere or the model blows up. Those cases where the model would have kept going, the solution is capped at the 50 percentile.
Between the MinQ and the MaxQ, all of the solutions on that curve are feasible solutions calculated for the estuaries. Each point along the curve is a separate analysis. At each point that is the maximum harvest that you can get given that amount of flow. We have a peak in the curve at maximum harvest. There are a million-acre feet where it does not seem to matter because you are at an optimum level of production.
There are systems that are freshwater sensitive. The mathematics will compute a real point for that optimization. In estuaries where freshwater is not normally limited, you wind up with broad flat curves. The same thing in the analysis of Matagorda Bay, Lavaca River, and the Colorado River flowing into it. In normal years, it gets plenty of flow. The result is that we get a broad curve. You do not have to pick maximum harvest or MinQ. There are solutions in between that can be investigated. The MinQ south is not a competent flow, does not provide the sediments, the nutrients, salinity gradient, biology, and the productivity in the fisheries. We turned off the other parts of the model and ran the salinity requirements to allow these animals to survive, grow, and reproduce, and calculated how much water it would take to keep the salinity within those bounds. This is the number that came out, 2.51 million-acre feet. Although the fisheries and nutrients equations were turned off, once you get that solution, you can run that through the fisheries equations and get a harvest of around 9.3 million pounds. Since we were able to generate a fisheries and a flow number, we plotted it on the rest of the curve so we could see where it was. The only problem is that when we do our analysis on the higher points of the range, we limit the operations of these equations, so there is no extrapolations. We trap the solutions within zones that we are pretty sure the equations are working. We had to violate that to generate those solutions for MinQ south, so I do not have as much confidence that you would get 9 million pounds of production.
The only number that we really have not had an opportunity to sit down with the Water Development Board and talk about is the MinQ SAL number. In years when you have 2-1/2, 3-1/2 million-acre feet of flow, this system produces about 5 to 6 million. There is a big overestimation caused by statistical extrapolation. One scientist who reviewed this material said that optimization curve is really kind of a fake because it gives the impression to people that when you see that curve and you look at the amount of flow, that that is the way it should be; and that is not it at all. This is the way it is calculated.
We calculate the means on a monthly basis for every month independently. We add it up to get the total, which is plotted on the curve; but there is a big difference between the MaxH and the MinQ in some seasons (May/June) where in order to get maximum harvest we have to have water all the way up to the median; but the MinQ still provides a good solution at a lower flow. In the wintertime additional diversion might not be a bad thing. It would provide additional water and improve the estuary, but we are not estimating as high a flow in this system in the wintertime as the system actually gets. Because it is MinQ and because it produces lower amounts of fisheries does not mean it is a bad solution. Even the MinQ meets the state management objective to maintain fisheries.
All points on that curve are at or above the average amount of production in the system, all of those solutions are accurate, and you can pick any one of those that you need for your management purposes. In good times you can afford to be more generous; in drier times you would have to be more cautious in your use of the water, but it is possible to safely operate diversion projects without affecting your yield and still produce benefits for receiving systems downstream.
The requirements in the statutes do not talk for short term. We are supposed to compute solutions that will maintain the full functionality of these systems over the long term. In dry times it would be important for us to know where the lower limits are for keeping animals alive, not giving them an opportunity to reproduce or grow, but just to keep them alive we need some critical flow level.
The recommendation was to look at how high the salinities could go in the system before there were large impacts on the plants and animals, and it is 2.5 million. You can see how much less that is than the amount of flow that it takes to maintain fisheries production in the system at or before its current levels.
We have investigated such things as expanding harvest relationships, extending the statistical models for harvest versus inflow, providing a better basis for the specification of inflow and salinity constraints. We have actually changed the constraints. We have done sensitivity testing. We have broadened the constraints. We have narrowed the constraints. Through this process we have achieved a balance between our desire to constrain the solution and our desire to produce a range of solutions that are broad enough to fit into water management schemes. All of these suggestions relate to things that we would do to improve our calculation of the freshwater inflow requirement.
This last one is different because when we finish and give a community or river basin an amount of flow that is desirable for the estuary, there is a whole other analysis adopted that they have to do, and that is operations. There is an infinite number of ways that you can do your operations and come up with a scheme that is suitable. The operational management tends to be a big thing and is often overlooked; and we are advising people, like river authorities, that if they have some extra time or money they should certainly start giving this one a look because now we have three or four solutions available for them that would be appropriate at different times. Some are good time solutions for when times are normal or above norm. Some are for when you get into a dry time. Others for emergency conditions that we might call drought. You have a multistage operation. You need some sort of scheme for operating so that you are doing the right thing at the right time at the right step in the normal hydrological cycle.
Implementation of beneficial inflows into practical project operations: We are continuing to get good recommendations for ways to improve the analysis, but the truth is that conditions do change in bays. You change your ship channels, realign things. As the bay changes, further analysis of inflows needs to be done. Your inflow may go up or down. You may need to adjust some parameter for changes in the fisheries. You do not want to get trapped with an unrealistic solution and then have that poured in concrete and never be able to study it or look at it again.
Feasible and adequate solutions are solutions which meet the constraints of the model: Salinity limits for viability of the animals where the animal does not die or fail to reproduce; state management objectives, which are the objective functions expressed mathematically, such as maintaining the fisheries; the statutes call for maintaining the productivity of the system and specifies economically important and ecologically characteristic species. We look at commercial fisheries or sports fishing where there is a lot of money involved in a species like red fish or oysters. Those animals are economically important, but we do not want to neglect one of the others that plays a major role in the food chain but is not really harvested. It may be the food item to something else that is harvested.
Each estuary is different. They have certain characteristics in what they produce and the ratios they produce it in, so that becomes a consideration in looking at the ecological characteristics and their economical importance. Maintaining their production is a legislative goal and the one we have tried to express mathematically by stating the average harvest of these commercially important species, plus or minus 20 percent, and also setting the salinity limits for these plants and animals.
When we say there is 5 million pounds of harvest, that is based on reported records of harvest, and that is a conservative number; but there was more harvest than that. It did not get reported in the statistics. It was not double or anything. You can not hide that much fish. The actual amount of production that came out of the system is not all accounted for.
When we use data that is conservative, that is called capitalization of industry. If there are enough boats, equipment, and people out there shrimping, the industry is capitalized. As long as the industry is fully capitalized, you can trust your statistics. You can tell the difference in their landings from a good year to a bad year. Commercial harvest data is an industrial data and does not measure up to scientific requirements. It is inaccurate, but it is the only database that runs for 30 years. We do not have 30 years of scientifically independent sampling from the bay to produce records to show how oysters, red fish, crabs, and shrimp change from year to year. We know what the problems are with the fisheries data and do extra testing with the Parks and Wildlife fishery independent database, which is a monitored scientific database they have been collecting for ten years. We look at ratios between fish and shrimp and see if those ratios are similar with the system, and the commercial operations ratios are matching up and are reliable in producing ratios that actually represent what the system is producing. We look at the fresh water inflows on the sampling they do. Their sampling network primarily samples juveniles. We use their bag seining records. The harvest records are adults. The adult animal records are based on several years of grow-out, whereas the sampling data from the bag seining are more immediate. Changes in the amount of animals in the bag seining sample are related directly to an immediate event, and we adjust the analysis for that when we relate inflows to production.
One recommendation was additional comparison of harvest fluctuations from year to year with bag seining or monitoring data that is collected by Parks and Wildlife. They use 20 to 30 years of fishery data to verify that the amount of freshwater available to create the right kind of habitat to salinity grade for the system matches up. They look at relative abundance in distribution of plants and animals. Parks and Wildlife and the TNRCC actually pick the point on the curve that they think balances the needs of man and nature at that condition. They might pick some point off that curse for a dry weather condition so that they will have the proper management goals at the different times of the hydrological cycle. For me MinQ is the minimum feasible solution, but Parks and Wildlife starts in good years with more assurity. They back up and create a zone of comfort, because that is the last feasible solution. You go beyond that point, you get into solutions that will not maintain the estuary. If you have 10 percentile occurring in all months, you cannot maintain the estuary; but our solutions suggest there are months that you cannot only tolerate it, it is actually the optimum amount of flow through there. In every system you will find that one month or more will bottom out, and we have let it bottom out at the 10 percentile and not let it go lower; and it does not appear to be too low. It meets the sediment, nutrient, fishery, and salinity requirements.
The tables to be used by consultants for the final report as directed by the Water Development Board omit bay and estuary inflow numbers but do include some water from the alluvium. Brown & Root will include the Region H inflow numbers as a footnote. Parks and Wildlife wants MaxH. MinQ is less than 4 million-acre feet per year. Reuse of existing water is a major portion of the supply. Parks and Wildlife does not want to see reuse and feels that ought to be dedicated to inflows. We need to provide a balance. Some believe that in the end period, the natural flows and return flows after reuse are probably going to be in excess of what really is required by the Galveston Bay.
Almost 1/3 of the freshwater inflows coming into the estuaries is not from major river basins but from local drainages and the coastal water shed. To calculate the fair share burden of one river versus another, you look at what it first contributed historically and maintain that so that one river does not feel the burden that should actually be borne by another. There are some numbers above the freshwater inflow number that ultimately provide the water that is on the bay and estuary line. You are double accounting by adding the bay and estuary line to the other numbers.
To affect the amount of flow an estuary is receiving, something drastic has to happen. There has to be profound water management practice changes. In the case shown we have a 2 million-acre foot cushion. It is doubtful whether conservation and reuse will reduce the flow by 2 million-acre feet.
REPORT FROM THE NOMINATING COMMITTEE:
Slate of officers recommended are the same; Executive Committee the same except for secretary. Mr. Ron Neighbors is suggested for that position. Vote to be taken at the January meeting according to the Bylaws.
TEXAS WATER DEVELOPMENT BOARD COMMUNICATIONS:
Two handouts provided guidance on unique stream segments and reservoir sites. One, questions and answers; the other, a process to quantify and identify unique stream segments of unique ecological value.
Overheads show amount of water currently in reservoirs in Texas. Red shows less than 1/3; green 1/3 to 2/3; blue more than 2/3 full. A significant number of the western half of the state is impacted by the drought. We have the least amount of water in storage going into December in the last 20 years. We have lost 3300-acre feet during November just from evaporation.
Glenda Callaway stated all facilities for public meetings for late February and March are confirmed.
Ron Neighbors mentioned Fort Bend Subsidence had a public hearing on the proposed disincentive fee adoption, which is on the agenda for the next board meeting. A portion of the environmental community testified in favor of adopting. The recommendation is $3 per thousand. The record is open until December 7 at 5:00 p.m.
Craig Pedersen thanked Senator John Lindsey for his attendance at this meeting and the board members for their time and efforts.
Discussion regarding request by Region G for this group’s participation in local scope of work for alluvium study on the Brazos.
MEETING ADJOURNED/NEXT MEETING:
January 5, 2000
San Jacinto River Authority, Lake Conroe Dam