Home / Media / News / NewsSearch
Results:
Tag: water quality
Clear

  • Releases from Gavins Point Dam reduced to winter rates

    Flow support for the 2022 Missouri River navigation season ended Nov. 21 as releases were reduced toward winter rates at Gavins Point Dam. “Releases from Gavins Point Dam are being reduced to the winter release of 12,000 cubic feet per second,” said John Remus, Chief of the Missouri River Basin Water Management Division.

  • Gavins Point Dam releases to be reduced to winter release rate in late November

    Six public meetings were held during the week of Oct. 24 to present current hydrologic conditions and the planned operation of the Missouri River mainstem reservoir system for the remainder of 2022. The public meetings were held in six locations in the Missouri River basin and a virtual public meeting was held Nov. 3. The meetings included draft plans for regulating the system in 2023. “We will continue to make releases from Gavins Point Dam to provide flow support at a level 500 cubic feet per second above minimum service, through the end of the navigation flow support season,” said John Remus, chief of the USACE, Missouri River Basin Water Management Division. “The flow support season will end three days early, on Nov. 28, at the mouth of the Missouri River.”

  • Drought conditions worsen in upper Missouri River Basin

    The time for the Fort Peck meeting was updated to 11 a.m. Due to scheduling conflicts, the St. Louis meeting has been canceled. September precipitation was once again below average in the Missouri River Basin. September runoff in the Missouri River Basin above Sioux City, Iowa was 0.6 million acre-feet, 47% of the long-term average. Soil conditions in the upper Missouri River Basin continue to be very dry. According to the Drought Mitigation Center, over 90% of the Missouri River basin is currently experiencing some form of abnormally dry conditions or drought, which is almost a 20% increase from the end of August.

  • Qualification of Hanna Instruments HI9829 for the Environmental Toolkit for Expeditionary Operations

    Abstract: A new, commercially available, field-portable water sensor was evaluated for efficacy during operation and compatibility with current Environmental Toolkit for Expeditionary Operations (ETEO) software. The ETEO provides sensors to Soldiers to rapidly identify and quantify environmental contamination in soil, air, and water at potential new base sites during initial reconnaissance to ensure safety and minimize unnecessary remediation efforts by the Army. In addition to streamlined environmental baseline survey (EBS) reporting, the ETEO can provide rapid analysis of potential environmental contamination to support various Military applications. The Hanna Instruments HI9829 multiparameter water meter was selected following a survey of commercial off-the-shelf (COTS) technologies and analyzed by researchers from the US Army Engineer Research and Development Center (ERDC) for inclusion in the ETEO design since it can rapidly and accurately measure 14 different properties. Usability tests were conducted with researchers unfamiliar with the technology, and a set of standard operating procedures (SOPs) were developed to operate the device. The software for the tool was successfully integrated into the ETEO system for rapid data analysis. The HI9829 has been demonstrated in various scenarios at ERDC and other locations; including Ft. Leonard Wood, MO, at which several visitors reviewed the operation of the equipment and other ETEO technologies. The Thermo Scientific Gemini, another sensor, which can detect organic constituents in various matrices via Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy was also investigated but eliminated from the ETEO design as it could not adequately detect a Military-relevant compound in an environmental matrix. Regardless, the addition of the HI9829 provides water quality monitoring to the ETEO design and greatly improves its capability to address various applications.

  • Fort Peck fall release reductions delayed

    Planned release reductions from Fort Peck Dam will be delayed until the end of September, due to the ongoing drought and recent extremely dry weather in eastern Montana.

  • Is Mean Discharge Meaningless for Environmental Flow Management?

    PURPOSE: River ecosystems are highly dependent on and responsive to hydrologic variability over multiple time scales (e.g., hours, months, years). Fluctuating river flows present a key challenge to river managers, who must weigh competing demands for freshwater. Environmental flow recommendations and regulations seek to provide management targets balancing socio-economic outcomes with maintenance of ecological integrity. Often, flow management targets are based on average river conditions over temporal windows such as days, months, or years. Here, three case studies of hydrologic variability are presented at each time scale, which demonstrate the potential pitfalls of mean-based environmental flow criteria. Each case study shows that the intent of the environmental flow target is not met when hydrologic variability is considered. While mean discharge is inadequate as a single-minded flow management target, the consequences of mean flow prescriptions can be avoided in environmental flow recommendations. Based on these case studies, a temporal hierarchy of environmental flow thresholds is proposed (e.g., an instantaneous flow target coupled with daily and monthly averages), which would improve the efficacy of these regulations.

  • Identification and Preventative Treatment of Overwintering Cyanobacteria in Sediments: A Literature Review

    Abstract: Freshwaters can experience growths of toxin-producing cyanobacteria or harmful algal blooms (HABs). HAB-producing cyanobacteria can develop akinetes, which are thick-enveloped quiescent cells akin to seeds in vascular plants or quiescent colonies that overwinter in sediment. Overwintering cells produce viable “seed beds” for HAB resurgences and preventative treatments may diminish HAB intensity. The purpose of this literature review was to identify (1) environmental factors triggering germination and growth of overwintering cells, (2) sampling, identification, and enumeration methods, and (3) feasibility of preventative algaecide treatments. Conditions triggering akinete germination (light ≥0.5 µmol m-2s-1, temperature 22-27℃) differ from conditions triggering overwintering Microcystis growth (temperature 15-30℃, nutrients, mixing). Corers or dredges are used to collect surficial (0-2 cm) sediment layers containing overwintering cells. Identification and enumeration via microscopy are aided by dilution, sieving, or density separation of sediment. Grow-out studies simulate environmental conditions triggering cell growth and provide evidence of overwintering cell viability. Lines of evidence supporting algaecide efficacy for preventative treatments include (1) field studies demonstrating scalability and efficacy of algaecides against benthic algae, (2) data suggesting similar sensitivities of overwintering and planktonic Microcystis cells to a peroxide algaecide, and (3) a mesocosm study demonstrating a decrease in HAB severity following preventative treatments. This review informs data needs, monitoring techniques, and potential efficacy of algaecides for preventative treatments of overwintering cells.

  • Development of a Three-Dimensional Vegetative Loss Mechanism for the Geophysical Scale Transport Multi-Block Hydrodynamic Sediment and Water Quality Transport Modeling System (GSMB)

    PURPOSE: The US Army Engineer Research and Development Center’s (ERDC) Environmental Laboratory (EL) and Coastal and Hydraulics Laboratory (CHL) have completed several large scale hydrodynamic, sediment and water quality transport studies. These studies have been successfully executed utilizing the Geophysical Scale Transport Modeling System (GSMB), which is composed of multiple process models (Figure 1). Due to being directly and indirectly linked within the GSMB framework, the US Army Corps of Engineers (USACE) accepted wave, hydrodynamic, sediment, and water quality transport models are both directly and indirectly linked within the GSMB framework.

  • Missouri River Basin drought conditions persist

    While the Missouri River basin has seen improved runoff for two consecutive months, it is not enough to overcome the long-term drought persisting in much of the basin. July runoff in the Missouri River basin above Sioux City, Iowa was 3.2 million acre-feet, which is 98% of average and 0.7 MAF more than was forecast last month. This has led to an annual runoff forecast of 20.6 MAF, which is 80% of average and 0.6 MAF higher than last month’s forecast.

  • June’s improved runoff not enough for Missouri River basin drought

    Despite improved runoff in June, water conservation measures will continue for the second half of the navigation flow support season based on the July 1 Missouri River Mainstem Reservoir System storage.