Hydrologic Forecasting in the Truckee-Carson RiverWare System

Michael P. Mann

ABSTRACT
The Truckee-Carson RiverWare modeling system is being developed as a joint effort between the Bureau of Reclamation (BOR) and the Truckee River Operating Agreement Implementation Coordinator’s Office. The framework of the current system consists of three interlinked RiverWare models that perform water accounting, hydrologic forecasting, and river-reservoir operations scheduling. The Operations Model requires daily streamflow (naturalized reservoir inflows and streamflow forecasts at both gaged and ungaged locations) and reservoir evaporation forecasts at numerous forecast points throughout the basin. The Forecast Model is used to provide these hydrologic forecasts to the Operations Model. The Truckee-Carson RiverWare system is currently used for general short-term planning purposes (several months to one year), but not for official water accounting or scheduling reservoir operations. In the future the RiverWare system will be crucial for water accounting and operations scheduling under implementation of the new Truckee River Operating Agreement.
This paper describes the configuration of the Forecast Model which was designed around the use of seasonal volume forecasts at three key forecast points in the basin. The Forecast Model distributes the input volumes temporally into daily flow hydrographs, and also distributes one of the volumes spatially to upstream forecast points. A “similar-years” approach is used to generate the daily flow hydrographs. The model determines similar years from historic runoff volumes and peak flow dates. The Forecast Model can also be configured to allow daily forecasts at any forecast point from a variety of other sources. Other sources of daily forecasts are the U.S. Geological Survey’s (USGS) Modular Modeling System model for the Truckee Basin, National Weather Service models for several forecast points in the basin, as well as any future models that may be developed.

Keywords:
Citation:
DOI:

Simulating Operations in the Truckee-Carson RiverWare Modeling System

Shane Coors

ABSTRACT
A Truckee-Carson Basin RiverWare operations model has been developed by the Lahontan Basin Area Office (LBAO) of the United States Bureau of Reclamation. This model simulates operations within the Truckee and Carson basins according to all current basin policy including the 1935 Truckee River Agreement, the 1944 Orr Ditch Decree, the 1959 Tahoe Prosser Exchange Agreement, the 1994 Interim Storage Agreement, and 1997 Operational Criteria and Procedures (OCAP). An overview of the model is presented, and examples of specific operations within the system are explored. The model runs on a daily timestep from the current time through the end of the calendar year. The model was developed in RiverWare© and includes a physical model of the basin comprised of objects and links, as well as a ruleset that prescribes the operational policy and physical constraints on the system. RiverWare’s simulation process is described and its rule writing interface and language are demonstrated. Several representative objects from the physical model are highlighted, and sample rules reviewed. Currently, the operations model is being substantially revamped to simulate the Truckee River Operating Agreement (TROA). TROA is an innovative, flexible operating agreement between the significant stakeholders in the Truckee-Carson Basin that allows for extensive exchanging and trading within the basin reservoirs. TROA presents many modeling challenges to the RiverWare modeling system as well as the LBAO modelers. A brief introduction to the fundamentals of TROA is given, followed by a survey of the many modeling intricacies that TROA requires.

Keywords:
Citation:
DOI:

Water Supply Accounting and Categorization in the Truckee Basin Using the RiverWare Model

Jeffrey T. Boyer

ABSTRACT
Operation of Truckee Basin reservoirs and administration of Truckee River diversions requires a complex water accounting system. The water accounting system is used to categorize and quantify stored waters and waters flowing in-stream on a daily basis. A new water accounting system has been developed using RiverWare software to replace a legacy spreadsheet system. The RiverWare water accounting system is one of a set of linked models that can be used under current reservoir operating policy. Significant additional layers of policy and logic are being added to the system for future use under a proposed river and reservoir operating agreement which is expected to be in place in 2007.

Keywords:
Citation:
DOI:

Characterization of Mercury Behavior in Steamboat Creek and Wetland Mesocosm

Scott Brown, Mae Gustin, and Laurel Saito

ABSTRACT
Aqueous mercury species behavior was studied in two environments of the contaminated Steamboat Creek (SBC) located near Reno, NV in the western United States. One environment was a three year old wetland mesocosm and the second, a 480 m reach on SBC with a low floodplain. The SBC watershed was contaminated with mercury in the late 1800s due to gold and silver processing at the headwaters of SBC. Since then, mercury has been well distributed along the creek and continues to be discharged to the Truckee River. The objective of this study was to provide data on the behavior of aqueous mercury species in SBC for future restoration efforts. The research showed that the spatial and temporal trends in species concentration of the two environments are fundamentally different due primarily to the nature of the flow environment. The reach study area exhibited the greatest seasonal variation in aqueous mercury concentrations and other constituents due to highly variable residence times, whereas the wetland mesocosm exhibited more consistent spatial trends due to longer and more constant residence times. For example, through the mesocosm, unfiltered and dissolved methylmercury concentrations increased an average of 40% and 25%, respectively.

Keywords:
Citation:
DOI:

Suspended Sediment Loading in the Middle Reach of the Truckee River, California, 2002-03

Gayle L. Dana, Anna K. Panorska, and Richard B. Susfalk

ABSTRACT
The goal of this project was to characterize the range and variability of sediment loads in the middle reach of the Truckee River according to total and maximum amounts, duration, timing and frequency of sediment transport events at four sites during 14 months within 2002 - 2003. Multiple linear regression models were developed to predict suspended sediment concentration from turbidity, streamflow, specific conductance, and water temperature. Suspended sediment loads were then calculated from the estimated concentration and measured streamflow. Monthly predicted suspended sediment loadings ranged from ~5 to 61 million tons/month, with the highest monthly loadings occurring during the snowmelt period (March – June). In the course of the 14 month data record, each site had a different number of sediment “events” (e.g., snowmelt, thunderstorms), ranging from 6 events (Truckee River at Tahoe City) to 94 events (Truckee River at Bridge 8). In addition, 10 dam release events were observed at the Tahoe City site. The sediment loading of individual events exhibited a near normal distribution, with events producing between 64 and 256 tons of sediment being the most frequently occurring. Event durations were most commonly in the 25 to 38-hour range. The dominance of this temporal signal is in part due to snowmelt events, which tended to follow a diurnal melting and loading pattern. Intensity of events (tons/hour) was most frequently in the 1 to 8 tons/hour range with the Truckee River near Truckee site exhibiting higher event intensities than the other sites.

Keywords:
Citation:
DOI:

Public Process and the Glendale Water Supply Improvement Project

Ronald James Penrose

ABSTRACT
In August, 2004, the Truckee Meadows Water Authority (TMWA) formed a “Working Group” to obtain public input on reconstruction of the Glendale Water Treatment Plant diversion.
TMWA’s and the Working Group’s goals were straightforward: To (1) revamp the diversion works to ensure a more reliable water supply to the Glendale Plant; (2) receive public input into evaluation criteria and concepts for the proposed diversion facility, and (3) complete the project by the end of 2008.
The process undertaken by TMWA staff to obtain public input started with an initial meeting for the general public in August 2004. Project goals were presented and membership into the Working Group was solicited. Thereafter, ongoing Working Group sessions were held approximately every three weeks to address one or two issues of concern. Subsequent public meetings were held to inform the general public of the project status and to obtain feedback. In addition to capacity and reliability issues, the following topics were carefully analyzed: Location, Construction Methods, Flood Control/Sediment Transport, Fish Passage, Boat Passage, and Environmental Issues.
A project alternatives evaluation was performed in conjunction with the Working Group to analyze potential weir locations and their associated impacts on performance and the environment. This evaluation resulted in selection of a “recommended project” which is now proceeding to final design and permitting.

Keywords:
Citation:
DOI: