This document presents the data collection and monitoring efforts that occur along the Truckee River by various organizations. This document is maintained by Jim Brock and Alan McKay of the Desert Research Institute.
Carollo Engineers
Walnut Creek, California
Reno/Sparks/Washoe Co. Truckee River Project
Summary
This document provides a description of data available to support water quality modeling in the Truckee River Basin (DSAMMt model). Conditions within the Truckee Basin have changed considerably throughout the 19th century (beaver importation, riparian tree removal, channelization, flow diversion for agriculture, flood control, Marble Bluff Dam, grazing, flow augmentation, riparian restoration, etc.). Future changes are expected associated with river operations, flood control, and channel restoration. Although it is one of the better studied rivers in the world, there are significant gaps in our knowledge of the system.
The major streams in Nevada have had TMDLs (Total Maximum Daily Loads) established for several years. However for some of these streams, the TMDLs are expressed as an average daily load based upon average long term flow conditions. These TMDLs have been dubbed as "bare bones" TMDLs due to the simplicity of the calculation and their lack of usefulness. While these TMDLs seem to satisfy the requirements of the Clean Water Act, they have contributed little to any watershed/waterbody assessment and restoration plans. These types of TMDLs do little to characterize the problems the TMDLs are intended to address. Without adequate characterizations, appropriate solutions cannot be identified and implemented.
For TMDLs to be more beneficial in the assessment and implementation process, TMDLs should reflect adequate water quality across flow conditions rather than at a single flow event such as average daily flow. Many states have begun to use load duration curves as a more robust method for setting TMDL targets. It is also a useful tool for better characterizing the pollutant problems over the entire flow regime. This paper discusses the steps taken to develop load duration curves and how they can be used in the assessment and TMDL process.
A duration curve is a graph representing the percentage of time during which the value of a given parameter (e.g. flow, load) is equaled or exceeded. Such a graph can be easily generated using a spreadsheet computer program. The following attachment presents the steps involved in developing a load duration curve.
This map represents the USGS Surface Water Gage Stations that are located within the study area of the Truckee River Information Gateway (TRIG). Data from these stations are used in the analysis phase of the TRIG project. The map is in jpeg format.
