Geologic Publications for Mount Rainier
Stream stage, stream temperature, stream turbidity, precipitation and air temperature for the Nisqually River at Longmire: Water year 2017
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Scott R. Beason
Water-Data Report NPS/MORA/WDR-2020/006
Mount Rainier National Park
Mount Rainier is a 4,392 m (14,410 ft) volcano in southwestern Washington State. Braided rivers radiate away from the volcano and are generally glacially-sourced. Approximately 4.17 km3
) of ice and perennial snows cover Mount Rainier (Driedger and Kennard, 1986). The mountain receives an average of 16.3 m (53.4 ft) of snow at Paradise and melting snow causes high flows in spring and summer months (NPS, 2011). Fall and winter storms lead to periodic flooding and higher flows. Generally, the lowest river flows occur late in the summer prior to the onset of fall storms and in the middle of winter. Most streams in the park exhibit a braiding or anastomosing character due to their glacial source, however, several of the lower order streams that have non-glacial sources exhibit pool-riffle morphology with very coarse median grain sizes. Average stream gradient ranges from 1 to 4%.
The Nisqually River is one of six major stream networks that drain a significant portion of the volcano (the others being the Puyallup, Carbon, West Fork White, White, and Ohanapecosh). The Nisqually River watershed (Figure 1) begins at the Nisqually Glacier and ends at the Nisqually National Wildlife Refuge, emptying into the Puget Sound. The Nisqually River at Longmire has a watershed size of 48.7 km2 (18.8 mi2), a mean basin elevation of 1,814 m (5,950 ft) and drains from the summit of Mount Rainier down to 853 m (2,800 ft) at Longmire (Table 1). The drainage basin includes three glaciers (Nisqually, Wilson and Van Trump Glaciers) and the permanent Muir Snowfield. Mean basin slope is 48.2% and has 39.0% canopy cover. Mean annual precipitation in the watershed is approximately 262 cm (103 in) (USGS Stream Stats, 2011). The Nisqually River’s headwaters start at the terminus of the Nisqually Glacier, at approximately 1,585 m (5,200 ft). From there, the river cascades down a steep braided stream with very coarse sediment. The river character is a classic braided system with multiple debris flow inputs from Van Trump Creek and other small streams.
Stream gage data from the Nisqually River at Longmire within Mount Rainier National Park are presented for water year 2017 (WY2017; October 1, 2016 – September 30, 2017). The Longmire location is now one of two year-round real-time gaging stations at the park; the other being on the White River at White River Bridge (see associated water-data reports for that location). Stream statistics are obtained via pressure transducers that are mounted within a stilling well at Longmire. Data from WY2017 was collected by a solar and battery-powered data collector and transmitted to the GOES West satellite where the data was then disseminated to a web-accessible database.
Stream gage data is useful for determining critical in-stream flows for aquatic habitats as well as showing the range of temperatures exhibited in park streams during the year.
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In Text Citation:
Beason (2020) or (Beason, 2020)
Beason, S.R., 2020, Stream stage, stream temperature, stream turbidity, precipitation and air temperature for the Nisqually River at Longmire: Water year 2017: Water-Data Report NPS/MORA/WDR-2020/006, Mount Rainier National Park, 31 p..