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Hemenway indicated the need to have metadata for production wells in the <br />State's database. <br />g. It was suggested that the SPDSS outreach efforts should focus on this <br />question of what's going on in the Denver Basin. <br />III. Ongoing Tasks (Phase 3) (Agenda Item 4) <br />A. Streambed Parameter Evaluation <br />Courtney Hemenway: Data and methodologies available from USGS in <br />Nebraska. <br />2. How do we extrapolate point measurements to reaches along the streams? <br />Gordon McCurry noted he hoped to work with this group on this. <br />3. This is all concerning relationship between stream and the alluvium, not bedrock. <br />4. The reports and visualization task could produce important information for the <br />outreach program. This will come after the modeling. <br />B. Alluvial groundwater modeling <br />5. Questions about the "pre-development modeling." Why do this pre-canal? <br />Response: This is to get the basic model configuration set up. In the next phase <br />(Phase 4), stresses will be added for pumping, recharge, etc. <br />IV. USGS Denver Basin Bedrock model (Agenda Item 5, presented by Suzanne Paschke) <br />A. A 12-layer model is being developed, using MODFLOW 2000. This model will <br />include all the confining layers and the alluvium. The confining layers are included <br />to account for the storage and for particle tracking. <br />B. The USGS currently is working on steady state calibration, to 1880 pre-development <br />water level conditions. They are also calibrating on streamflow. They are doing this <br />on base flow as a flux calibration. This is being done on a few tributaries in the <br />upper part of the basin. <br />C. They are not including the irrigation canals at this point. Question: doesn't this <br />overlook an important source of recharge? <br />D. Although the alluvium is being modeled as a separate layer, Ned Banta of the USGS <br />said they are not modeling the alluvium with great detail; they are using the alluvium <br />more as a boundary for bedrock conditions and will be calculating a flux between the <br />alluvium and the Denver Basin aquifers. <br />E. Discussion on conductance (river to alluvium) and the vertical hydraulic conductivity <br />of alluvium to Denver Basin: Bob Longenbaugh asked how we know what the <br />vertical hydraulic conductivities are between the streambed and alluvial aquifer, and <br />between the alluvial and bedrock aquifers. <br />F. It was decided to have another session focusing on calibration and stream to aquifer <br />connection and alluvium to bedrock aquifer connection. <br />12 <br />