Geology ReportsSearch

Geology topics

K. E. Miltenberger

Publications and source records attributed to K. E. Miltenberger.

4 recordsLinked to original sources

Morphometric and geological characterization with statistical correlations for 33 tributary drainage basins of the San Juan River watershed in the Four Corners region, USA

Basin morphometry, climate and geology control how a hydrological network evolves over time, controlling the efficiency of weathering of elements from geological materials, and ultimately the input of sediment and dissolved constituents to river systems. Exceedances to the Navajo Nation surface water quality standards for trace metals have been reported in the San Juan River watershed. Because metals are transported adsorbed to fine-grain sediment, the identification of areas with elevated sources of trace metals and/or areas with increased erosion and sediment transport potential is an important first step in protecting water quality. Physical factors such as elevation, slope, relief and stream order were used to quantify morphometric parameters that effect the contribution of trace metals into the stream network. By correlating these parameters with water quality data that were collected from tributaries along the San Juan River, we identified statistically significant regressions between morphometric parameters and total Al, Pb, U, Fe and Mn in surface water. Positive correlations with trace metals include tributary drainage basin perimeter, pour point elevation and total number of streams, while negative correlations include stream length ratio, ruggedness number and longest basin axis. Stream reach measurements within geological units that contain known trace metal constituents reveal that Gallegos Canyon and Desert Creek are the most susceptible to sediment mobilization and transport, while other tributary drainage basins, such as Desert, Recapture and Salt creeks, are associated with naturally elevated concentrations of Al, As, Pb and U.

Arizona, Colorado, New Mexico, Utah

A comparison of water-quality and stormwater inflow and outflow during habitat restoration at the McEwen storm drainage pond, South Valley, Albuquerque, New Mexico, 2020–22

In 2020, the U.S. Geological Survey began targeted monitoring, in partnership with Bernalillo County, at three locations within the McEwen storm drainage pond to evaluate and compare the water quality of stormwater as it enters and exits the study area, which is channelized and routes urban stormwater runoff through a wetland area. Stage in McEwen pond and precipitation at a nearby precipitation gage were evaluated to observe relations between rainfall and stage, as well as how long the stage remained elevated at the site. Peak stage ranged from 0.73 to 2.4 feet, with the time to reach peak stage at McEwen pond ranging from 45 minutes to 10 hours and 45 minutes. The stage remained elevated for a median of 3 days. Monitored water-quality parameters included physical parameters, bacteria, sediment, and nutrients. Bacteria was the only parameter that frequently exceeded the New Mexico Water Quality standard. Significant differences (p less than 0.05) among sites were few, consisting of those for total nitrogen and dissolved ammonia concentrations, which decreased toward the middle of the pond and were lower in the outflow from the pond compared to concentrations at the east and west sites. The middle of McEwen pond showed an increase in the percentage of fine-grained sediment, which suggests that larger particles settled into the pond and were further filtered as water traveled through the swales. Concentrations of suspended sediment and dissolved nutrients were significantly lower in 2022 compared to previous years. Although the site is still undergoing restoration and plants are becoming established, observations over the last several years indicate that site restoration has resulted in changes to the study area through processes such as nutrient uptake and the filtering of larger sediment particles.

New Mexico

Suspended-sediment transport and water management, Jemez Canyon Dam, New Mexico, 1948–2018

Construction and operation of dams provide sources of clean drinking water, support large-scale irrigation, generate hydroelectricity, control floods, and improve river navigation. Yet these benefits are not without cost. Dams affect the natural flow regime, downstream sediment fluxes, and riverine and riparian ecosystems. The Jemez Canyon Dam in New Mexico was constructed in 1953 by the U.S. Army Corps of Engineers with authorizations for flood control and sediment retention. Water managers of the dam use various operational techniques to restore peak streamflow, improve sediment management, and restore altered ecosystem processes, while maintaining the authorized purposes of the dam. This study focuses on four distinct reservoir management operation periods implemented at the Jemez Canyon Dam: (1) predam (pre-1953), (2) a seasonal 24-hour hold pool (1953–79), (3) a permanent pool (1979–2001), and (4) dry reservoir (2001–18). Results of this study indicate successful flood control and reduction in peak instantaneous streamflow events following construction of the dam, specifically documented in 1958 and 2013. During the second water management operation period, moderate sediment retention (also defined as trap efficiency, which is the percentage of incoming sediments trapped within a reservoir during a given time) occurred (between 41.0 and 67.0 percent of sediments were retained). During the third period (1979–2001), between 61.2 and 99.8 percent of sediments were retained. During the fourth period (2001–18), at least 1,909 acre-feet of accumulated sediment were remobilized. The estimated dam trap efficiency during the fourth water management operation period was −37.2 percent, indicating that more sediments were being removed from the Jemez Canyon Reservoir than were being deposited. These remobilized sediments supplemented the natural sediment delivery in the Jemez River to the middle Rio Grande. The current (2022) dry reservoir operation allows sediment delivery during periods when flooding is not a concern while still providing flood control when needed. Suspended-sediment particle size data indicate potential coarsening of suspended sediments during the fourth water management operation period, likely resulting from erosion of coarse bed sediments deposited in the reservoir. Suspended-sediment particle size data during the first and fourth water management operation periods indicate that finer sediment mobilized during monsoon season than during snowmelt. Also, suspended-sediment concentrations during the predam and post-hold pool periods indicate concentrations were higher during monsoon season than during snowmelt. Seasonal variations in suspended-sediment concentration and particle size may help dam managers make operational decisions by increasing the understanding of particle size, concentration, and variation of suspended sediment during a given year. The seasonality of suspended-sediment transport can also vary, depending not only on concentration and particle size, but on precipitation. The maximum annual suspended-sediment loads occurred during all three seasonal categories analyzed in this study: snowmelt, monsoon, and the remainder of the year. This indicates that, in addition to sediment particle size and concentration, understanding the variability of transport mechanisms of suspended-sediment load can also guide optimal water management operations at a dam.

New Mexico