Record Details
page 3-15
Digital Collections at BYU
| Field | Value |
|---|---|
| Title | page 3-15 Final environmental impact statement on the Provo River Restoration Project, page 3-15 |
| Coverage | Electronic reproduction; |
| Format | 3-15 text/PDF |
| Rights | Brigham Young University; http://lib.byu.edu/about/copyright/generic.php Public Domain Public |
| Language | English; eng; en |
| Relation | Central Utah Project; Western Waters Digital Library; action would impact infiltration and discharge of water along the provo river channel there would be no overall loss or gain of surface water to groundwater however in the northern part of the valley along the provo river river seepage could increase as the surface area of the stream bed increases slightly raising groundwater levels 13 1 3 feet in the northern most mile of the river this additional seepage could occur where the stream bed is in a losing reach of the river ie the stream bed is higher than groundwater and river water is seeping into the ground under baseline conditions the river in this area reaches 8 and 9 see map 31 3 1 is incised because of erosion and downcutting down cutting of the river channel invert under the proposed action the channel invert would be raised and the flow of the river would not be confined within existing dikes groundwater levels are shallow in the area and would likely adjust to match the grade of the river groundwater levels would depend on the final design grade of the river groundwater levels would not change if the final grade is similar to the present channel elevation conversely groundwater is discharging to the river in the south central part of the valley one to two miles upriver from deer creek reservoir along the provo river in this gaining reach of the river where the stream bed is lower than surrounding groundwater groundwater discharge could increase and groundwater levels would likely be lower than under baseline conditions by up to 1 foot groundwater recharge in the areas of ofheber heber valley not adjacent to the provo river would be the same as under baseline conditions groundwater discharge would be impacted by changes in the grade of the river channel in areas where the groundwater table is directly related to the stage depth of flow of the river the average groundwater discharge impacts in in heber valley along the provo river under the proposed action are less than one tenth of 1 percent greater than baseline as shown in table 34 3 4 during a dry year there would be a small decrease in groundwater basin discharge approximately 40 acre feet the dry year decrease in discharge would be offset by a comparable increase in discharge during wet years resulting in no net loss or gain over an extended period the increased loss of 40 acre feet during a dry year represents less than 0.02 002 percent of the total flow of the river which is far 3 less than the accuracy of methods used to measure water flow the changes in groundwater levels storage and discharge summarized above would not impact wells and springs in heber valley 3263.3 32633 32633 impact summary surface water travel time would have an average increase of about I 1 1 hour at 500 cfs cs for flows from jordanelle danelle Jor to deer creek reservoirs because of the longer channel and slower flow velocities during a dry year the increased length of river channel would cause an estimated increase of 40 acre feet in net river channel seepage to groundwater the greatest changes in groundwater levels would be an increase of about 13 1 3 feet in the northern portion of the valley adjacent to the river these groundwater level increases would be associated with changes in the grade and length of the river channel which affects the surface area and seepage interaction between the river and groundwater basin 326.4 3264 3264 existing channel modtfi modification cation catlon alternative the following subsections describe potential water resource impacts from construction and operation of the existing channel modification alternative 3264.1 32641 32641 surface water impacts under the existing channel modification alternative a series of step pool reaches would be constructed in the existing river corridor which would slow the velocity of flow in the pool reaches time of travel of the flow from jordanelle Jor danelle to deer creek reservoirs would increase from 3.9 39 39 hours to 4.1 41 41 hours at a flow rate of 500 cfs cs 3264.2 32642 32642 groundwater impacts no impacts on groundwater gro dwater undwater un levels return flows or wells and springs would occur under the existing channel modification alternative 3264.3 32643 32643 impact summary surface water impacts would be limited to an average increase of about 12 minutes in the time of travel of flows from jordanelle Jor danelle to deer creek reservoirs no quantifiable changes in groundwater levels recharge or discharge would occur 15 |
| Identifier | http://cdm15999.contentdm.oclc.org/cdm/ref/collection/WesternWatersProject/id/8083 |
