SAN JOAQUIN RIVER Dissolved Oxygen Total Maximum Daily Load Stakeholder Process

Amount Requested: $157,280

Applicant: Dr. Carl W. Chen

Systech Engineering, Inc.

3180 Crow Canyon Pl., Ste 260

San Ramon, CA 94583

925-355-1780

carl@systechengineering.com

 

Members of Technical Advisory Committee

This study element will evaluate various management alternatives to bring the DO in DWSC (Deep Water Ship Channel) above the standard to protect migratory fish and other residence aquatic lives. The management alternatives may include various combinations of point source control, nonpoint source control, barriers and pumping operations (to increase SJR river flow), in-stream aeration, and flow management of discharges from wetlands, grasslands, Stockton, and others. The effectiveness of alternatives will be evaluated with the DO model of the DWSC and the newly calibrated DSM2 for the upstream. The formulation of management schemes and model evaluation will be conducted under the direction of the TAC.

A large number of adaptive management schemes can be formulated to meet the DO standard in the lower San Joaquin River DWSC. The alternatives may include various combinations of flow regulations (operable barriers or flow re-circulation), point source and nonpoint source load reductions, in-stream aeration and flow management of discharges from wetlands and grasslands in the upstream. The model can be used to simulate how the DO in DWSC may respond to the management alternatives. In year 2000, the preliminary DO model has already been used in Strawman analysis. Results indicate that a river flow of 250 cfs will require a much greater reduction of point source load from the City of Stockton and river load from the upstream. With a SJR flow above 500 cfs, smaller load reduction is needed to reduce the maximum daily DO deficit in DWSC. The dredging of DWSC from historic 8 feet to current 35 feet greatly increased the maximum daily DO deficit in DWSC. Through this type of analysis, it is possible to evaluate not only what alternative works, but also who are responsible parties for the DO depletion.

The input data of the model includes point source loads from various dischargers, river flow, and river loads. All these input parameters can be changed to reflect the management alternative. The model will predict the DO concentrations in DWSC under each proposed management scenario. The predicted DO can be used to determine if the alternative can meet the DO standard.

The point and nonpoint discharges and hydraulic residence time of SJR determine the DO concentration in the DWSC. The management alternative cannot rely on the control of any single factor. Combination alternatives are most cost effective and equitable to all stakeholders.

This project will calculate the TMDLs of Stockton discharges and river loads from upstream. It will also calculate the TMDLs of discharges from wetlands, grasslands, and other discharges upstream of Vernalis. The study will generate a large number of management scenarios that can help DWSC meet the DO standard. The TMDL Steering Committee/CVRWQCB can use the information to select a preferred alternative that is technically sound, feasible, and equitable to all responsible parties.

San Joaquin River from Mud Slough to DWSC.

The input data to the models will be set up to reflect the management scenarios. The models will then predict whether the DO standard can be met. The analysis will take two steps. The first step is to determine the combinations of SJR flow, Stockton load, and river load that can help DWSC meet the DO standard of 5 mg/L and/or 6 mg/L. The second step will use DSM2 to evaluate the possibility of flow management at wetlands and grassland that can reduce the river load to the level called for in step one. If not, the model will be used to evaluate additional load reduction needed for BOD and nutrients from other discharges from agricultural lands and other sources.

The project will have four tasks:

Task 1: Analysis of TMDLs for Stockton load and upstream river load. This is a continuation of the Strawman loading analysis initiated in year 2000, using the preliminary DO model. In year 2001, the calibrated DO model will be used to perform the calculations. As before, the TMDLs to meet the DO standard at DWSC will be calculated for different levels of SJR flow. This will give the DO TMDL Steering Committee information to choose a preferred SJR flow and TMDL plan that is equitable to all responsible parties. In this task, a sensitivity analysis will also be performed to determine the possible statistical spread of DO responses under the preferred TMDL scenario. This will provide the Steering Committee/CVRWQCB information about the chance of not meeting the DO standard due to model uncertainty and other uncontrollable factors.

Task 2: Analysis of TMDLs for discharges from wetlands and grasslands in order to meet the river load requirement determined in Task 1. Dr. Chris Foe of the Regional Central Valley Water Quality Control Board performed a Strawman loading analysis in year 2000. The spreadsheet calculations indicate that the discharges from wetlands and grasslands are major contributors to the river loads at Vernalis. The river loads at Vernalis are transported in part downstream to become the river loads to DWSC. In year 2001, the calibrated DSM2 model will be used to perform the calculations. After the calculations, engineering analysis will be performed to determine whether the TMDLs can be met by the flow management of the discharges. If not, a calculation will be made to determine additional load reductions needed from other discharges. A sensitivity analysis will be performed to determine the chance of not meeting the river load requirement due to model uncertainty and other uncontrollable factors.

Task 3: Design and feasibility analysis of an adaptive management system for the improvement of DO in DWSC. The adaptive management system will include some real time sensors of flow and water quality at selected stations, a communication system to transmit information back and forth with a centralized location, a model to forecast DO condition in DWSC, and a set of management options that can be used to improve DO in the DWSC.

Sensors can be set up to provide continuous monitoring of inflows and pollution loads (e.g. wetlands, grassland, Stockton) and river loads at Vernalis and Mossdale. There will also be a continuous monitoring station at Rough and Ready to indicate the level of DO in DWSC.

Possible management options will include flow management of discharge from wetlands, flow management of discharge from Stockton, control of river flow by an operable barrier at the Head of Old River (HOR), and an aeration system that can be triggered at a moments notice.

The adaptive management system will include a communication system to send data to a centralized location via Internet. The idea of real time adaptive management is to forecast inflow and pollution loads into the future, based on the continuous monitoring data. The forecasted inflow and pollution loads will be fed to the model, which predicts the DO in DWSC. If the predicted DO is below standard, the model will be exercised to find a combination of management options to meet the standard. The operational plan will be issued to each operator for implementations. The forecast can be made for two weeks (or months), but updated every week (or month) in a recursive manner.

The predicted DO response and actual DO can be saved for post auditing. The post auditing results can be used to improve the operation of the adaptive management system for the next year.

Main purpose of this task is a proof of concept. Many operational scenarios based on actual time series of data will be evaluated with the model. The TAC members will make suggestions on how to develop operational scenarios.

The model results will be stored in spreadsheets. The spreadsheet files will be sent to TAC members via the Internet. The TAC members will send email to offer their suggestions for operational scenarios.

The deliverables include reports, presentations, and predicted effectiveness of adaptive management alternatives to meet the DO standard in the DWSC.

The work will be carried out in one year. The alternatives involving river flow and reduction of Stockton load and river load will be analyzed first. It will be followed by the analysis of alternatives involving upstream dischargers, wetlands flow management and nonpoint loads from agricultural and other sources. The evaluation of adaptive management schemes will be performed last.

Dr. Carl W. Chen will serve as the principal investigator. Dr. Chen earned his M.S. and Ph.D. degrees from University of California, Berkeley. Dr. Chen has developed the DO model of the lower San Joaquin River. He has performed Strawman loading analysis for the lower San Joaquin River. He guided the development of the graphical user interface of SJRIODAY for the real time water quality management of the upper San Joaquin River.

Progress reports will be submitted quarterly. The model results will be provided to TAC members from time to time via Internet. The final report will be submitted at the end of the project.