Agenda Item: PRRIP EIS and National Academy of Science Update

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-7- DOI (see Platte River Channel Dynamics Investigation, Parsons, May 2003). The Parson's conclusions cast serious doubt regarding the definitive conclusions reached by DOI. The Sed Veg model does appears to have some value however, significant process relationships (geomorphic, plant physiology and the linkage of the two) and calibration and verification issues persist. This "tool" forms the foundation upon which all assumptions and projections of impacts are formed. The National Academy of Science (NAS) review of Endangered and Threatened Species on the Platte River, April 2004 had the following remarks regarding Sed Veg: "The committee did not evaluated three items.... an advanced computer model, SEDVEG, to evaluate interactions among hydrology, river hydraulics, sediment transport, and vegetation being developed, but not yet competed or tested (emphasis added), by the USBR for application on the Platte River, and "...the committee did not access the newer models because they have not been completed or tested, but recommend that they be explored for their ability to improve decision making. (emphasis added). The NAS further states: "The committee also recognizes that there has been no substantial testing of the predictions resulting from the DOI's previous model work, and it recommends that calibration of the models be improved". There are significant unknowns regarding the use of Sed Veg and the DEIS should not rely on the promising but unproven tool. The DEIS contains no summary of the accuracy and precision of Sed Veg both in terms of it's model processes and the raw data that is used for model runs. For example is the precision of the flow and sediment data and vegetation germination and mortality data greater than the predicted trends? The DEIS team clearly had concerns in this regard as they inappropriately modeled trends for 61 years even though the length of the action alternatives is only 13 years. Any analysis done on the action alternatives should be directly linked to the period of the federal action. In addition, there is no quantitative discussion of the required river stage change and the number of days needed to create sand bars and how that information is accounted for in the model or whether it historically occurred. The DEIS analysis appears simplistic with a one to one relationship between river stage and sand bar formation. No data is provided in the DEIS showing that the prescribed flow relationships and the magnitude and duration of flow recommendation and Sed Veg modeling will result in the scouring of vegetation. It is equally likely that the hypothesized processes for vegetation removal will have the opposite effect by: 1) distributing seedling with a short term pulse and 2) late summer irrigation (release of so called forage fish flows) to ensure the survival and growth of the seedling and narrowing of the channel. It is requested that the Sed Veg model not be used to describe impacts. Given the uncertainties in the knowledge a more qualitative assessment is needed with the understanding that the action alternatives will monitor effects and offset negative impacts as necessary using proven habitat management methods. The DEIS grossly understates the benefits of habitat acquisition and management and restoration provided by the Governance Committee Alternative, especially in relationship to the species use and needs on the Central Platte. The management of 10,000 and ultimately 29,000 acres of habitat for the species is conservatively more than enough to ensure that the Platte River is not limiting recovery (see Management Joint Study and References). The Flood Protection • Water Project Planning and Finance • Stream and Lake Protection Water Supply Protection • Conservation Planning