Retention and detention basins are engineering constructions with multiple objectives; e.g., flood protection and irrigation. Their performance is highly location-dependent, and thus, optimization strategies are needed. LOCASIN (Location detection of retention and detention basins) is an open-source MATLAB tool that enables automated and rapid detection, characterization and evaluation of basin locations. The site detection is based on a numerical raster analysis to determine the optimal dam axis orientation, the dam geometry and the basin area and volume. After selecting a reasonable basin combination, the results are summarized and visualized. LOCASIN represents a user-friendly and flexible tool for policy makers, engineers and scientists to determine dam and basin properties of optimized positions for planning and research purposes. It can be applied in an automated way to solve small and large scale engineering problems. The software is available on GitHub.

The Cambridge Sustainable Drainage (SuDS) Design and Adoption Guide provides comprehensive guidelines for implementing and maintaining sustainable drainage systems in urban developments. It outlines various SuDS features, including permeable paving, swales, ponds, and wetlands, emphasizing their role in mimicking natural drainage processes to manage surface water runoff effectively. The guide also details the adoption process, maintenance responsibilities, and integration with planning policies, aiming to enhance flood resilience and water quality in the Greater Cambridge area

Beaver dam mimicry is an emergent conservation practice. We evaluated the influence of constructed riffles, a unique type of beaver mimicry aimed to store water and allow fish passage, on habitat for fishes in one control reach and one manipulated reach with mimicry structures added. The beaver mimicry reach had deeper pool habitats and deeper and wider riffle habitats compared to an unmanipulated control reach. Dissolved oxygen was similar among reaches, averaging 8.7 ± 0.2 and 8.9 mg/L in the beaver mimicry and control reaches, respectively. Sediment size was also similar among reaches, with a D50 of 8.1 and 10.6 mm in the beaver mimicry and control reaches, respectively. The beaver mimicry reach had little to no overhanging bank vegetation or riparian vegetation shade cover, while the control had 38% of its bank covered by canopy and 56% overhung by vegetation. These riparian characteristics result from a legacy of livestock grazing and lack of consistent vegetation planting during restoration. Longnose dace (Rhinichthys cataractae) and white sucker (Catostomus commersonii) dominated in the beaver mimicry reach, together comprising 70% of the fish assemblage post-structure installation. Arctic grayling (Thymallus arcticus) was not found in the beaver mimicry reach but was present in the control, albeit in small numbers of only 3% of the assemblage post-structure installation. These results highlight the need to consider both in-stream and riparian habitat features for fishes, as well as timescales of both hydrological and ecological outcomes in restoration design.

Controlling sediment produced by water erosion is the highest environmental challenge in steep, open pit sand mines located in erosive climates. Although restoration is impractical in active mine areas, sedimentation ponds are the Best Available Technique by the European Union to reduce sediment spillages from these environments. Few studies have described and supported such a solution with high resolution data. The María José mine is one of two active kaolin mines in the mining area of the Alto Tajo Natural Park, a highly erosive setting. It has a complex maintained pond system as a hydrologic and sedimentary control measure. In this landscape, mining can only be sustainable if clean water from production is ensured. The pond system retains sediment and water during a rain event, deposits the sediment, and eventually spills the water under controlled events. The María José spillages have been continuously monitored for suspended sediment concentration and water discharge at the mine outlet since 2012. During four years the efficiency of the pond system varied (96.7–99%), producing an average annual sediment yield of 5.6 Mg ha−1 y−1, a reduction of 98.4% compared with the sediment yield reported for similar local mines having no ponds. A quarter of this sediment was produced under controlled spillages allowing runoff management; the rest during large rainfall events when runoff decreased pond efficiency gives rise to an increase in suspended sediment concentration, as is typical of local natural rivers. Provided continuous maintenance, sediment ponds are shown to be a successful method to produce clean water. Successful pond efficiency implies that a mine produces water and sediment during baseflow conditions, allowing sufficient sediment volume to accumulate during rainstorms.

The creation of ponds and wetlands has the potential to alleviate stream water quality impairment in catchments affected by diffuse agricultural pollution. Understanding the hydrological and biogeochemical functioning of these features is important in determining their effectiveness at mitigating pollution. This study investigated sediment and nutrient retention in three connected (on-line) ponds on a lowland headwater stream by sampling inflowing and outflowing concentrations during base and storm flows. Sediment trapping devices were used to quantify sediment and phosphorus accumulations within ponds over approximately monthly periods. The organic matter content and particle size composition of accumulated sediment were also measured. The ponds retained dissolved nitrate, soluble reactive phosphorus and suspended solids during baseflows. During small to moderate storm events, some ponds were able to reduce peak concentrations and loads of suspended solids and phosphorus; however, during large magnitude events, resuspension of deposited sediment resulted in net loss. Ponds filtered out larger particles most effectively. Between August 2019 and March 2020, the ponds accumulated 0.306 t ha−1 sediment from the 30 ha contributing area. During this period, total sediment accumulations in ponds were estimated to equal 7.6% of the suspended flux leaving the 340 ha catchment downstream. This study demonstrates the complexity of pollutant retention dynamics in on-line ponds and highlights how their effectiveness can be influenced by the timing and magnitude of events.

The influence of long-term suspended sediment dynamics on stormwater pond performance should not be ignored, but is often neglected in pond design and performance evaluation. This paper provides systematic simulated quantification of long-term suspended sedimentological effects on stormwater pond performance. Integrated hydrological and two-dimensional hydro-morphodynamic modelling and simulations were carried over a 32-year period (1984–2015) covering 3896 rainfall events with a wide range of rainfall volumes, durations and intensities. Three event-based hypothetical rainfall scenarios: non-flood condition (5-year), sewer design condition (30-year), and river flood condition (100-year) rainfall events with 1-h duration, were also simulated for comparison between the traditional event-based approach and the novel approach presented in this study. Simulation results show that the flood peak attenuation and delay are more pronounced for small (<5-year) and medium (<30-year) flood events. The long-term continuous simulation results indicate that the pond provides positive annual trap efficiencies varying from 2% to 69% for 31 of 32 years, providing long-term water quality benefits downstream. However, an extreme rainfall event in year 2012 flush out the accumulated sedimentation as a shock load to the downstream river, leading to a negative trap efficiency of −11%. The spatially averaged sediment deposition rate, as predicted by the model, varies with a mean (SD) of 2 (1.34) cm/year over the study period, which resulted in a 24% loss in the pond’s volume over 32 years. The impact of the loss in storage on pond flood attenuation capacity are explored at regular time intervals over the study period. The results indicate that reduction in the pond’s flood attenuation capacity is relatively more pronounced for medium (30-year) and extreme (100-year) flood events than the frequent small flood (5-year) events. The variation in annual sediment loading with rainfall quantities and patterns are also explored.

The training aims to empower municipalities, NGOs, and key civil stakeholders with the knowledge and skills necessary to select and implement environmentally conscious solutions for water retention and sediment management. Participants will learn how to mitigate the effects of drought, slow runoff, restore wetlands, improve damming/retention, re-naturalize watercourses, protect against erosion & landslides, and enhance ecological succession through nature-based solutions. The textbook consists of four chapters and each is accompanied by a PPT presentation (can be adjusted based on specific needs and availability).

Chapter 6 explores Beaver Dam Analogues (BDAs), which are human-constructed, semi-permeable structures designed to mimic the ecological and geomorphic functions of natural beaver dams. Built from natural materials such as wood posts, willow branches, and sediment, BDAs aim to restore fluvial systems by altering hydrology, sediment transport, and habitat complexity. Like natural beaver dams, BDAs function best when installed in series and require careful site selection to maximize ecological benefits.

This chapter outlines BDA construction techniques, including starter dams, post lines with wicker weaves, and reinforcement of existing beaver dams. It describes how BDAs can raise water tables, reconnect floodplains, aggrade incised channels, and enhance aquatic and riparian habitats. Over time, BDAs promote successional transitions from open water to wet meadow systems, contributing to a dynamic, resilient habitat mosaic.

Beaver mimicry is a fast-growing conservation technique to restore streams and manage water that is gaining popularity within the natural resource management community because of a wide variety of claimed socio-environmental benefits. Despite a growing number of projects, many questions and concerns about beaver mimicry remain. This study draws on qualitative data from 49 interviews with scientists, practitioners, and landowners, to explore the question of how beaver mimicry projects continue to be promoted and implemented, despite the lack of comprehensive scientific studies and unclear regulatory requirements. Specifically, we investigate how these three groups differentially assess the salience, credibility, and legitimacy of evidence for beaver mimicry and analyze how those assessments affect each group’s conclusions about the feasibility, desirability, and scalability of beaver mimicry. By highlighting the interaction between how someone assesses evidence and how they draw conclusions about an emerging natural resource management approach, we draw attention to the roles of experiential evidence and scientific data in debates over beaver mimicry. Our research emphasizes that understanding how different groups perceive salience, credibility, and legitimacy of scientific information is necessary for understanding how they make assessments about conservation and natural resource management strategies.

In the semiarid and arid western United States, it is important to understand the potential effects of stream restoration on surface-water and groundwater. In this study, we evaluate the seasonal and annual hydrologic impacts of beaver-dam analogue (BDA) restoration in the Blacktail Creek (BTC) Watershed south of Butte, Montana. We monitored surface water flow, groundwater levels, temperature, and specific conductance primarily using a control-treatment study design. In treated reaches, groundwater levels were closer to the ground surface and showed less seasonal fluctuation. Changes in overall streamflow in the control reaches had stream losses and gains varying from -21.0 to 19.9 % while treatment reaches had stream gains of 12.5 to 17.6 % of water returning to the stream through groundwater discharge. Using specific conductance values and streamflow, the total dissolved load was greater in the treatment reaches compared to the control reach. Two-components mixing model showed that treatment reaches had a greater overall groundwater contribution to the stream during high-flow periods compared to control reaches. Control and treatment late-season vertical hyporheic exchange flows had similar vertical exchange flows but there were greater overall horizontal flows in the treatment reach. BDA implementation creates small off-channel ponds; provides increased groundwater gradients away from the stream during late-season periods, and gradients to the stream during drier years. BDAs increase ecosystem resilience while storing water during reduced snowpack years. Groundwater discharge to streams in treatment reach and groundwater recharge in control reach is evident during high-runoff periods. BDAs can be an effective management tool when applied to the proper setting with a well-defined restoration goal.