Operating Levels. The system operation shall be split into three operating levels that build on one another and, in the event of a breakdown, cause different response times for removing such breakdown.
Operating Levels. The operating level for Echo and Xxxxxx Lakes has been established from experience and from input in the Qu’Appelle Basin Studies from the 1970’s. A graph of the operating range and average water level from 1945 to 2008 is illustrated in Figure 2. The desirable operating range is listed in Table 2. Figure 2 Xxxxxx and Echo Lake Operating Range and Average Daily Level Table 2 Desirable Operating Range for Xxxxxx and Echo Lake Month Jan Feb Mar Apr May June Upper Level 478.54 (m) 1570.0 (ft) 478.38 1569.5 479.3 1572.5 479.3 1572.5 479.15 1572.0 479.15 1572.0 Lower Level 478.23(m) 1569.0 (ft) 478.23 1569.0 478.23 1569.0 478.17 1568.8 478.54 1570.0 478.84 1571.0 Month July Aug Sept Oct Nov Dec Upper Level 479.15 (m) 1572.0 (ft) 479.15 1572.0 478.99 1571.5 478.84 1571.0 478.69 1570.5 478.54 1570.0 Lower Level 478.84 (m) 1571.0 (ft) 478.84 1571.0 478.66 1570.41 478.54 1570.0 478.38 1569.5 478.23 1569.0 TYPICAL OPERATIONS In a typical year, all logs are removed in the fall from the Echo Lake dam. Water levels drop down to a point that the lake level is controlled by a high spot in the Qu’Appelle River downstream of the dam or by Katepwa Lake levels. In the spring time in a normal year, the water level rises to a point near the summer operating range, with no logs in the structure. This is caused by the runoff upstream of Pasqua Lake. When Xxxxxx and Echo Lakes are near the summer operating level of 479.15 m (1572 ft) and the inflows are beginning to drop, the logs are installed into the dam. From that time forward in any given year, the control structure is operated to maintain the lake at or below 479.15 m (1572 ft). In the fall, typically after September 8th, logs are removed in several operations to lower the lake for spring runoff. During extreme years, the operation of the Echo Lake control structure may vary considerably. In drier years, logs are installed into the structure early in the spring. Xxxxxx and Echo Lakes will not rise above the summer operating level in the spring in the dry years. In order to conserve water and protect the aquatic ecosystem in the lakes, as much of the spring runoff will be stored as possible. An earlier operation will allow the lake to approach the summer operating range. It should be noted that often water is brought into the lakes from either Last Mountain Lake or Lake Xxxxxxxxxxx to stabilize lake levels. In wet years, the installation of the logs will be delayed until such time as the lake drops back into the summer opera...
