PRRIP Water Advisory Committee Meeting Notes

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133 134 135 ' 136 137 138 0 11' 1 PRRIP — ED OFFICE DRAFT 6 10/02/2008 the November WAC meeting to continue this discussion (most likely November 13). North Platte Channel Capacity Project — Discussion on budgeting for 2008 fall removal of un- sprayed phragmites, with spraying again next fall for re- growth. Jerry will revise the estimate to include some spraying, potentially with proposal for matching efforts of LB701 (upper limit of — $50K). 139 14o Hydraulic Model, North Platte to Grand Island — The recent hydraulic model update by the BOR 141 was focused in part on bank storage, but there was not enough budget (under $25K) to gather 142 better cross - section data. The proposed 2009 effort would use 1 -foot contours from LIDAR 143 topography to update cross sections with some additional field work surveys. The LIDAR flight 144 will be this fall with tree leaf off, low flow, no snow. Boyle's model is not a hydraulic model; it 145 is a 1 -day time -step spreadsheet model. The proposed 2009 effort would be primarily to support 146 AMP geomorphology and pulse flow modeling. The WAC expressed concern that this tool is for 147 "planning" and objectives of how it will be used have not been defined enough. Jerry explained 148 that the BOR model was not developed with a loop and branch process; trial and error has to be 149 used to raise and lower the channel bottom. Don Anderson said that for pulse flow planning, the 150 Program needs the best tool possible to know timing and how water that is sent downstream from 151 the Environmental Account will travel through the system. Jerry explained that the sediment 152 augmentation model, SEDVEG, was used for this previously and the Program will be spending 153 under $50K for the BOR to make refinements to another model to see if the vegetation portion 154 can be added. Jerry explained that a good hydraulics model is at the basis of any sediment 155 transport model. A HEC -RAS model could also be used to evaluate changes associated with 156 phragmites and other changes in the system. The WAC raised additional questions about how 157 the $300K budget estimate was proposed and asked for a better understanding of how this will be 158 used for water management purposes. Jon Altenhofen recommended consideration of using an 159 extensive monitoring effort (e.g. piezometers) versus modeling. 160 161 Channel Losses Study — The WAC recommends doing more research into what has already been 162 done in the past and how it could be utilized and would like a better understanding of how this 163 will be used for water management purposes, considering how use of OPSTUDY and the HDR 164 Conjunctive Management model may be used to accomplish goals versus a new HEC -RAS 165 model. 166 167 Water Action Plan Update — The HDR Conjunctive Management modeling will be key to further 168 refining aspects of the WAP, which will be the cookbook for how the Program accomplishes 169 target flow goals. Jon Altenhofen recommended that the ED Office be able to run any models 170 and use tools developed by consultants versus relying on outside contractors. The goal is at the 171 end of 2009 to have the planning done and be ready to implement projects. Jon Altenhofen 172 indicated he believes the Program may be able to focus 2014 goals on recharge projects and then 173 focus construction for other additional goals. Duane Hovorka indicated concern that there may 174 not be enough budget to be able to start design work at the beginning of 2010. The ED Office 175 will work with Boyle to provide more detail on the scope, phasing it so that projects can be 176 implemented in 2010 and the ED Office is trained t use the planning tools. The WAC discussed Page 4 of 5