The Central Nebraska Public Power and Irrigation District
Groundwater Mound Study
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Purpose Main Objectives Evaluate the groundwater mound in the
vicinity of lands irrigated by CNPPID facilities Provide an
understanding of the temporal and spatial changes of the
groundwater mound Identify factors affecting the groundwater
mound
Key Terms CSD Wells Database of water levels from wells used in
CSD report
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Key Terms Study Area
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Groundwater Mound Study Recap Estimated Mound Volume CSD well
method Water balance method Subareas Spatial and Temporal Movement
Adjustment Impact Diversions ET
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Groundwater Mound Size and Shape Annual Groundwater Mound
Volume
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Groundwater Evaluation Water Balance
Slide 9
CSD Mound Volume Compared to Water Balance Mound Volume Mound
Volume Calculated using the Water Balance Mound Volume Calculated
using CSD Well Data
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Water Balance Adjusted Diversions Annual Groundwater Mound
Volume No Diversions 50% Diversions 75% Diversions CSD Well Data
125% Diversions 100% Diversions 25% Diversions
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Water Balance Adjusted ET Annual Groundwater Mound Volume 95%
ET 98% ET 105% ET 102% ET CSD Well Data Un-Adjusted ET
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Primary Conclusions Groundwater Mound Size and Volume
Increasing trend from the 1950s to 2000. No longer an increasing
trend since 2000.
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The Future of the Mound Declining Surface Water Recharge
Reduced Water Supply in Lake McConaughy (Allocations) Increased
efficiencies (Conservation) 1950-2000 average recharge = 145,000 af
Since 2000 average recharge = 90,000 af Declining Mound Negative
Water Balance