Laserfiche WebLink
4- 19 <br />4.2.6 Surface Water Quality <br />• Surface water flows within the permit area are limited to ephemeral drainages and a reach <br />of East Salt Creek that is intermittent. Site details are addressed in Section 2.4.1 and shown on <br />Figure 2.2-3. East Salt Creek is the primary drainage and passes through the western portion <br />of the permit area in a north to south direction. A number of secondary drainages enter East <br />Salt Creek to the east and west from the major canyon features and small isolated watersheds <br />along the creek periphery. Drainage systems typically exhibit active flow only during spring <br />snow melt and as runoff during storm periods. <br />Water quality is typical of arid climate, ephemeral systems located in marine deposited <br />sedimentary land forms. A high degree of variation in quality is encountered dependent on <br />antecedent moisture conditions and water source. Waters are generally basic in nature and <br />reflect asulfate -bicarbonate system. Dissolved constituents often reach very high levels <br />following dry periods and during the wintertime. Stream flows during these periods are almost <br />entirely made up of recharge from ground water and from stagnant or semi•staghant pools. <br />Suspended solids levels are usually high during spring runoff and local high quantity storms due <br />• to the high erodibility of the local land form and sparseness of area vegetative cover. Periods of <br />best water quality occur during spring snow melt. Dissolved constituents are at their lowest <br />during this period due to the dilution effect on relatively large quantities of flow than encountered <br />during other seasons. <br />Historical surface water quality data taken from the USGS gauging station on East Salt <br />Creek are presented in Tables 4.2-8 and 4.2-9. Data collected from East Salt Creek at the <br />north end of the permit area are presented in Table 4.2-6. Periodic "grab" samples from East <br />Salt Creek, McClave Canyon and the Colorado River are presented. These data reflect the wide <br />variation in seasonal and antecedent conditions described above. <br /> <br />M` Volume 1 4 -29 - 96 <br />