Record Details
page 3.2-26
Digital Collections at BYU
| Field | Value |
|---|---|
| Title | page 3.2-26 Finding of No Significant Impact Lake Fork Section 203 Alternative : Proposed Action, page 3.2-26 |
| Coverage | Electronic reproduction; |
| Format | 3.2-26 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; feeder pipeline diversion reaches LF 7 and LF 8 proposed action average flows would be up to about 10 cfs cs about 26 percent higher than baseline during more than half of the year and from 2 to 65 cfs cs 14 to 23 percent lower than baseline primarily during late spring and early summer the C canal diversion structure would be operated in a manner to accommodate the passage of instream instrearn in stream flows released from moon lake reservoir downstream to the big sand wash feeder diversion structure as well as designated bypass flows originating at stabilized high mountain lakes in the upper yellowstone drainage the benefits of leaving flows in the river would be most apparent during dry water years when reaches LF 7 and LF 8 between the C canal diversion and the proposed big sand wash feeder diversion structure have little or no flow in late summer and fall the hydrologic model tends to mask these absolute flow conu bonu commitments nitments during an average water year since predicted flows are based on all water years including the 4 wet water wator years this causes average flow values to exceed the in stream flow conu bonu commitments nitments between the ccanal mcanal CC C anal canal anai and big sand wash feeder diversion structures instream In stream flows for fish are defined by values that were presented in table 2.24 224 22 224 4 and in the operating agreement from the big sand wash feeder pipeline diversion to the rivers confluence with the duchesne river reaches LF 9 through LF 12 proposed action average flows would be generally lower than baseline especially in january february and june about 40 to 80 cfs cs and 30 to 70 percent lower than baseline the 2 5 10 and 20 year ranked annual peak flows and percent change in flows estimated for the proposed action were used to assess potential impacts on aquatic and wildlife resources wetlands and threatened and endangered species the 20 and 50 year data which illustrate the potential effect on peak flood discharges and fluvial processes show that peak flood discharges downstream of moon lake dam would decline up to about 10 percent but not change significantly compared to baseline conditions depending on river reach 20 year flood flows would vary from 1171 to 2068 cfs cs compared to baseline values of 1162 to 2167 cfs cs 50 yearflood year flood values would vary from 1317 to 2251 cfs cs under the proposed action compared to baseline values of 1292 to 2396 cfs cs the 5 year and 10 loyear year peak flows downstream of moon lake dam would decline up to about 13 percent but not significantly compared to baseline conditions depending on river reach the 5 year flood flows would vary from 826 to 1381 cfs cs compared to baseline values of 840 to 1463 cfs cs 10 loyear year flood flows would vary from 1035 to 1857 cfs cs compared to baseline values of 1039 to 1943 cfs cs by comparison the 2 year flood flows would decline by a larger percentage up to 38 percent in some reaches ranging from 274 to 716 cfs cs under the proposed action versus 443 to 829 cfs cs under baseline conditions again depending on river reach these data are summarized in table 3.13 313 31 313 3 in the water resoiirces resources and hydrology section of the final technical memorandum effects on fish habitat that would result from these modeled flow changes are discussed in the aquatic resources section of this chapter 32421.4 324214 324214 irrigation canals and seepage overall les ies lesswater less water swater would be diverted for agricultural use during spring high flow periods than under baseline conditions project mai mal water would be available throughout the year as needed and project irrigation water 3226 32 26 |
| Identifier | http://cdm15999.contentdm.oclc.org/cdm/ref/collection/WesternWatersProject/id/11827 |
