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  • Swimming Area Reopened at Blue Marsh Lake

    The swimming area at Blue Marsh Lake’s Dry Brooks Day Use Area has been reopened for public use. Water quality test results now indicate that E. coli bacteria levels have returned to a level that meets state standards for swim beaches. The public is reminded that swimming at Blue Marsh Lake is at one’s own risk, and lifeguards are not on duty. The U.S. Army Corps of Engineers wants you to stay safe.  Don’t become a statistic – and always be prepared for the unexpected!

  • Qualitative Habitat Evaluation Index for Louisville Streams (QHEILS)

    Purpose: Urban stream restoration typically involves multiple objectives addressing different aspects of ecosystem integrity, such as habitat provision, geomorphic condition, watershed connectivity, water quality, and land-use change. Multiple stream assessment tools and models have been developed and applied to inform restoration prioritization, planning, and design. Here, we present the Qualitative Habitat Evaluation Index for Louisville Streams (QHEILS, pronounced “quails”), which was designed as an interdisciplinary assessment method for urban streams in the Louisville, Kentucky, metropolitan region. The model adapts a regional habitat assessment procedure, the Qualitative Habitat Evaluation Index (QHEI), by incorporating additional processes related to geomorphic change and watershed connectivity. The QHEILS was developed in the context of the Beargrass Creek Ecosystem Restoration Feasibility Study, and it provides a rapid procedure for assessing multiobjective benefits associated with proposed restoration actions. This technical note summarizes the model and provides example applications within the Beargrass Creek watershed.

  • Swim Beach Closed at Blue Marsh Lake

    Swimming at the Dry Brooks Day Use Area of Blue Marsh Lake is currently restricted due to high bacteria levels. Water sample results obtained from testing over the weekend indicated high levels of e-coli bacteria.  The swim beach will remain closed until bacteria levels return to a safe level for public use. This restriction applies to designated swim area.  Picnicking, boating, and other activities are not currently restricted. Visitors that choose to enter the water for activities in other areas of the lake are reminded that the water is not tested, and that swimming at Blue Marsh Lake is at one’s own risk. Updates will be provided as conditions change.

  • System operations returning to normal post flooding

    Significant rainfall led to an above average runoff in the upper Missouri River Basin. June runoff was 6.6 million acre-feet, which is 119% of average and 2.6 MAF higher than forecast. A strong weather system moved into the basin on June 21 producing excessive rainfall in eastern South Dakota, north central and northeastern Nebraska, and northwestern Iowa. The rainfall totals exceeded 600% of normal over the 24-hour period.

  • Elevated E. coli levels close Gremlin Cove Beach at Harlan County Lake

    Due to high E. Coli concentrations, officials at Harlan County Lake have closed the Gremlin Cove Beach. Officials will retest the water on June 11, 2024, and results will be available the following day. The beach will remain closed until levels fall below 235 colonies per 100 ml water.

  • May runoff slightly above average; Fort Peck flow test continues

    Active rainfall patterns across the Midwest provided much needed moisture to several portions of the Missouri River Basin. Large areas of Montana, North Dakota, Wyoming, eastern South Dakota, and eastern Nebraska received more than 200% of normal precipitation for the month of May. However, central South Dakota, western Nebraska, and eastern Colorado received as little as 25% of normal precipitation.

  • pH Pivoting for Algae Coagulation: Bench-Scale Experimentation

    Abstract: Harmful algal blooms (HABs) threaten recreational waters and public supplies across the US, causing detrimental economic and environmental effects to communities. HABs can be mitigated with dissolved air flotation (DAF) treatment, which requires addition of pH-sensitive charged chemicals to neutralize algae, allowing them to attach to microbubbles and float to the surface. During HAB events and photosynthesis, algae raise the pH to levels that are not ideal for DAF. Traditionally, pH is reduced with a strong acid; however, this adds operational cost and permanently adjusts the water’s pH. This study assessed an approach that might allow for infusing CO₂ from diesel-powered electricity generators into the water prior to DAF treatment. It was hypothesized that formation of carbonic acid could temporarily reduce the pH. Results showed that 2.5%–5.0% CO₂ mixed within compressed air can achieve pH levels between 6–7 in algal water with an initial pH of 9–11 and alkalinity of 150 mg/L as CaCO₃. Further, dosing CO₂ before chemical addition yielded a 31% improvement in water clarification. Returning the pH back to natural levels was not achieved using ambient air microbubbles; however, coarse bubble air spargers should be tested to provide more volumetric capacity for CO₂ absorption.

  • Management Strategy for Overwintering Cyanobacteria in Sediments Contributing to Harmful Algal Blooms (HABs)

    Purpose: Cyanobacteria that cause harmful algal blooms (HABs) can overwinter in sediments as resting cells (akinetes or vegetative colonies) and contribute to seasonal bloom resurgences. However, to date there has been limited focus on management tactics specifically targeting the control of cyanobacterial sources from sediments. Targeting resting cells in sediments for preventative management may provide a viable approach to delay onset and mitigate blooms (Calomeni et al. 2022). However, there are limited resources for this novel strategy. Given the growing global impact of HABs, there is a need to develop management strategies focused on sediments as a potential source and contributor to HABs. Therefore, the objective of this report is to provide a management strategy in terms of approaches, information, and case study examples for managing overwintering cyanobacteria in sediments with the goal of mitigating seasonal HAB occurrences.

  • Monitoring Geomorphology to Inform Ecological Outcomes Downstream of Reservoirs Affected by Sediment Release

    Abstract: Increasingly, reservoir managers are seeking techniques that improve sediment management while considering long-term sedimentation and reduced operational flexibility. These techniques, often termed sustainable sediment management, involve passing sediment through reservoirs and into downstream rivers. Conceptually, restoring sediment continuity can benefit ecosystem function by increasing floodplain connectivity, contributing to the heterogeneity of channel geomorphology, and supporting the continuity of nutrient cycling. However, when a change is made to operations, geomorphic changes may need to be monitored to document benefits and mitigate any unexpected effects of the change. This investigation develops a geomorphic monitoring plan for downstream reaches affected by sediment-release operations at reservoirs. The monitoring objectives are aligned with potential geomorphic change caused by changes to sediment supply and the associated effects on river function. A tiered approach is presented to explain the quality of information that can be assessed from increasing levels of data collection. A general conceptual model is described in which geomorphic data may be linked to physical habitat conditions and, therefore, ecological processes. The geomorphic monitoring plan for the Tuttle Creek Reservoir water injection dredging (WID) pilot project is presented as a case study. This technical note establishes a general framework for monitoring the design for sustainable sediment management in different ecological and geomorphic contexts.

  • Missouri River Basin runoff forecast improves but remains below average; Fort Peck Flow Test underway

    As warmer weather moves into the Missouri River Basin, spring precipitation brought some much-needed moisture throughout the basin. For the month of April, runoff was 2.1 million acre-feet, 71% of average, for the basin above Sioux City, Iowa. The annual runoff forecast for the upper Missouri River Basin above Sioux City is 19.2 MAF, 75% of average, and 1.7 MAF higher than last month’s forecast.