Geology topics

L. M. Nelson

Publications and source records attributed to L. M. Nelson.

8 recordsLinked to original sources

USGS1987

Flood characteristics for the Nisqually River and susceptibility of Sunshine Point and Longmire facilities to flooding in Mount Rainier National Park, Washington

Inundation from 25-, 50-, 100-, and 500-year floods at Sunshine Point and Longmire facilities and the Longmire visitors ' center and ranger station generally is not a serious hazard as long as the existing dikes and banks of the Nisqually River and Tahoma Creek remain intact and flood capacities of the channels are maintained. However, average water velocities during floods are high (as much as 23 ft/sec) and the channel, banks, and some dikes are composed of unstable materials. Sunshine Point campground is particularly susceptible to flooding and damage from Tahoma Creek, and to a lesser extent from the Nisqually River, if large amounts of debris or rock material accumulate in the channels and change the flood elevation or courses of either stream. At Longmire flood inundation or damage from the Nisqually River is much less, but flooding is still possible. There, high ridges upstream protect the several park facilities from the river, but accumulations of debris or rock in the channel could cause flooding from overtopping of dikes or riverbanks. Glacial outburst floods are a matter of serious concern at both Sunshine Point campground and Longmire. Glacial outbursts can and have produced very large flood discharges and transported large quantities of debris and rock materials. Although none have been known to transport these materials from Tahoma Glacier as far as Sunshine Point campground, one in 1955 from Nisqually Glacier (estimated at 70,000 cu ft/sec near the glacier) did appreciably increase the magnitude of the water discharge at Longmire. For safety, campers and visitors need to be advised about the potential flood hazards at both facilities.

Washington↗

USGS1986

Reconnaissance of the water resources of the Hoh Indian Reservation and the Hoh River basin, Washington

Ground- and surface-water resources of the Hoh Indian Reservation and the Hoh River basin were studied from 1977 to 1980 under a cooperative agreement between the U.S. Geological Survey and the Hoh Indian Tribe. It was determined that moderate quantities of groundwater can be obtained from near-surface, river-deposited sands and gravels on the northeastern part of the reservation. Groundwater recharge (induced by pumping from a nearby oxbow lake) could supply numerous wells indefinitely with yields of 25 to 50 gallons/min. Geologic units in other areas of the reservation appear to have a low hydraulic conductivity and would yield little, if any, water to wells. At seven sites where housing construction is planned, soils were tested for infiltration rates and it was determined that soils are adequate for waste disposal in septic tanks and associated drain fields at those locations. Chalaat Creek, which flows across the reservation, provides water for salmon-rearing ponds. Except for moderately high bacteria concentrations (fecal coliform bacteria concentrations were as high as 33 colonies/100 mL), results of water quality analyses indicate no unusual or harmful concentrations of any chemical constituent or physical properties of the water that would restrict its use for most purposes. Chemical and bacteriological analyses of the Hoh River and its major tributaries downstream from the Olympic Park boundary revealed no unusual or harmful levels of constituents, with some minor exceptions. Small increases in concentrations of sodium, chloride, nitrite plus nitrate, and turbidity were measured in water samples collected from the Hoh River in a downstream direction. These increases are probably the result of natural weathering of rocks and soils in the basin. Fluvial-sediment transport of the Hoh River was 82,000 tons from March 1978 to February 1979 and 1,510,000 tons from March 1979 to February 1980. Mean annual transport was estimated to be 630 ,000 tons. About 60% of the sediment transported by the Hoh River originates from within the boundaries of the Olympic National Park, which includes about 70% of the area of the Hoh River drainage basin. (USGS)

Water-Resources Investigations Report↗

USGS1986

Effect of bank protection measures, Stehekin River, Chelan County, Washington

An investigation of the lower Stehekin River was conducted to study the effects on flood elevations and velocities from four bank protection and flood prevention measures that are being contemplated as a means of reducing erosional losses of river bank property. These measures are: bank armoring, armored revetment levees, spur dikes, and redevelopment of old cutoff channels. The banks at seven study sites could be armored without adverse effect on the flood velocities and elevations. The largest increases due to armoring--up to 1.6 ft/sec in velocity and 1 ft in elevation--occurred in the vicinity of sites 5, 6, and 7 where the gradient of the river channel is about 50 ft/mi and the velocities are high to begin with (about 6 to 13 ft/sec). The use of a levee in conjunction with armoring on the northeast bank from sites 5 to 7 would increase the velocities as much as 2.8 ft/sec and increase the elevation as much as 1 ft, but it would also provide some flood protection to the east bank, which is frequently inundated. Spur dikes were considered a practical alternative only at site 3, where reduced bank erosion may occur without aggravating flood inundation or erosion elsewhere. The rerouting of flood flow through an old cutoff channel near site 1 increased the velocity by 3.2 ft/sec and the elevation by 1 ft for the 100-year flood; however, it would move floodwater away from residential property where bank erosion is a problem. The few other old channels that shortcut river bends where much erosion occurs are apparently already part of the channel during floods. (Author 's abstract)

Water-Resources Investigations Report↗

USGS1985

Water-surface elevations for the high tide of December 15, 1977, in the Puget Sound region, Washington

An unusually high oceanic tide on December 15, 1977, caused flooding of lowlying, nearshore parts of western Washington, including several areas in the Puget Sound region. At Seattle, the December 15 high tide of 14.8 feet above MLLW (mean lower low water datum; 8.55 feet above the National Geodetic Vertical Daltum of 1929, or NGVD) was 0.1 foot higher than the 100-year high tide. At Neah Bay, near the western end of the Straits of Juan de Fuca, however, the high tide of 8.77 feet MLLW (4.55 feet NGVD) on that date was 3.2 feet lower than the 100-year high tide. This study has identified the observed December 15 high-tide elevations at many locations in the Puget Sound region. The observed high tide then was much higher than predicted in most of the Puget Sound region, primarily as the result of a very low barametric pressure. Little damage from wind waves was reported. Elevation profiles for the predicted and observed high tides on December 15 and for several other selected tide levels indicate an increase in the maximum height in the inland direction, except near Port Angeles, and show abrupt changes in tidal elevations at three constrictions - Admiralty Inlet, Tacoma Narrows, and Deception Pass. (USGS)

Water-Resources Investigations Report↗

USGS1983

Flood elevations for the Soleduck River at Sol Duc Hot Springs, Clallam County, Washington

Elevations and inundation areas of a 100-year flood of the Soleduck River, Washington, were determined by the U.S. Geological Survey for the area in the vicinity of the Sol Duc Hot Springs resort, a public facility in the Olympic National Park that under Federal law must be located beyond or protected from damage by a 100-year flood. Results show that most flooding could be eliminated by raising parts of an existing dike. In general, little flood damage is expected, except at the southern end of an undeveloped airstrip that could become inundated and hazardous due to flow from a tributary. The airstrip is above the 100-year flood of the Soleduck River.

Water-Resources Investigations Report↗

USGS1982

Streamflow and sediment transport in the Quillayute River basin, Washington

From October 1976 to September 1978 the U.S. Geological Survey made a reconnaissance evaluation of the fluvial-sediment transport and documented the natural streamflow characteristics in the Quillayute River basin in northwestern Washington. Most of the flow originates from the tributaries, the Soleduck, Bogachiel, and Calawah Rivers. Flow in the summer months from the Calawah River is about half that from either the Bogachiel or Soleduck Rivers. In the winter months flow from the Soleduck River is about 1 1/2 times that of the Bogachiel or Calawah Rivers. In general, the highest monthly flows during the winter are about 10 times greater than the lowest monthly flows during the summer except for the Dickey River where winter flows are about 20 times greater. Annual mean discharges may vary greatly from year to year, ranging from about 1/2 to 1 1/2 times the mean annual discharge. For the study period, the observed suspended-sediment concentration ranged from less than 1 to 2 ,150 milligrams per liter. The estimated mean annual suspended-sediment discharges were: Bogachiel River--400,000 tons (includes Calawah River); Calawah River--120,000 tons; Soleduck River--120,000 tons; Dickey River--75,000 tons; and other tributaries--10,000 tons, for a total of 606,000 tons transported annually by the Quillayute River. The estimated annual bedload of 21,000 tons was transported into the Quillayute River by the Soleduck, Bogachiel, and Dickey Rivers. (USGS)

Open-File Report↗

USGS1981

Channel conditions in the lower Toutle and Cowlitz Rivers resulting from the mudflows of May 18, 1980

During several periods of volcanic-ash eruption at Mount St. Helens, Wash., (March 30, May 25-26, May 30-June 2, and June 12-13, 1980) strong winds from the north occurred at high altitudes. As a result, the volcanic ash fell some 50 miles to the south in the Bull Run watershed, the principal water-supply source for the metropolitan area of Portland, Oreg. Water samples collected from three stream sites within the watershed were compared with samples collected during the same season in previous years. No detectable changes were noted in chemical characteristics. Precipitation samples collected immediately after the June 12-13 ash fall ranged in specific conductance from 20 to 41 micromhos per centimeter at 25C and in pH from 4.0 to 4.3 pH units. Stream samples collected during the May-June period ranged in specific conductance from 18 to 28 micromhos per centimeter at 25C and in pH from 6.7 to 7.5 pH units. Volcanic-ash samples were collected and analyzed for particle size, chemical composition, and weight. Significant differences in particle size of ash were found in samples from two separate eruptions. (USGS)

Circular↗

USGS1972

Potential transport of sediment from Enloe Reservoir by the Similkameen and Okanogan rivers, Washington

This study was undertaken to determine the probable effects on the Similkameen and Okanogan Rivers of the removal, transport, and deposition of sediment now deposited behind Enloe Dam on the Similkameen River, if the dam were removed. Under existing conditions of sediment transport, the average annual suspended-sediment discharges at three streamflow-measuring sites are calculated to be 134,000 tons for the Similkameen River near Nighthawk, 175,000 tons for the Okanogan River near Tonasket, and 175,000 tons for the Okanogan River at Malott. The volume of sediment in Enloe Reservoir was computed to be 1.79 million cubic yards (about 2.4 million tons). The sediment is largely sand. If the dam were removed the maximum amount of reservoir sand transportable (in addition to normal sediment discharge), under stated conditions of velocity and depth during any average 10-year period, would range from about 17,000 to 580,000 cubic yards per year, with about 320,000 cubic yards being transported during a year of average water discharge. These volumes represent a range of 32 to less than 1 percent of the volume of sediment now deposited in the reservoir. The reservoir deposits not carried to the mouth of the Okanogan River (at Columbia River) would be deposited largely in a 17-mile reach of the Okanogon River immediately downstream from its confluence with the Similkameen River. Deposition of the reservoir sediment would tend to reduce the capacity of the channel of the Okanogan River in this reach; also there possibly would be some long-tern adjustments of the stream course to the temporary increase in the sediment load. Locally, the reduction in the channel cross section probably would increase the depth of the water and area of inundation during floods. Deposition of sediment in the Okanogan River channel and accompanying undesirable effects would be less severe if the dam were removed in segments over a period of several years. If the dam is removed in segments the amount of sediment transported by the river could be monitored to evaluate (1) the timing of the removal of the remaining segments of the dam, based on actual sediment-transport data, (2) the amount of sediment rremaining in the reservoit, and (3) the impact of sediment deposition on channel configuration and flooding.

Open-File Report↗