Sediment Retention Ponds Research Articles

Comparative study of sediment loading in sub-watersheds of Phewa Lake, Nepal

The present study assessed the potential of sediment loading in Beteni, Lauruk, Andheri, and Harpan sub-watersheds of Phewa Lake and estimated the sediment yield in the year 2020. Morphometry, land use/land cover, geology, climate, and human and development factors of the sub-watersheds were studied to assess the potential of sediment loading in the sub-watersheds. SRTM DEM was used for the computation of morphometric parameters and land use/land cover maps were prepared by using Landsat imagery. Geology, rainfall data, census data, and road maps were collected from various secondary sources. The sediment yields of the four sub-watersheds in the year 2020 were estimated by measuring the sediment volume deposited in the sediment retention ponds at the outlet of each sub-watershed. Results indicated that Beteni had the highest potential for sediment loading, while Harpan had the lowest. Likewise, the sediment yields for Beteni, Lauruk, Andheri, and Harpan sub-watersheds in 2020 were estimated at 1,420.67 m3/km2/year, 2,280.14 m3/km2/year, 1,666.77 m3/km2/year, and 766.42 m3/km2/year, respectively. To reduce sedimentation in Phewa Lake, it is recommended to regularly maintain siltation dams and construct check dams along the drainage slopes, alongside other soil conservation measures and appropriate land use practices in the upstream areas of the sub-watersheds.

The effect of inlet width on the performance of sediment retention ponds in thermally induced flows

The effects of inlet configurations in sediment retention ponds (SRPs) have been widely investigated by several researchers. However, when considering temperature differentials in the ponds where density and buoyancy change with temperature the challenges associated with the proper inlet design still exist. The buoyancy forces are generated due to the differences in temperature potentially changing the flow in the pond by forming density currents. This study evaluates the effects of different inlet width ratios (IWRs) on the flow pattern and residence time in a sediment retention pond when inflow is colder or hotter than the water in the pond. In this research, an innovative experimental setup was used to create the temperature differentials. The results in the present study show that when the inflow temperature is colder than the water temperature in the pond, increasing the inlet width to the full pond width can effectively increase the pond’s performance. Likewise, when the inflow temperature is hotter than the water temperature in the pond decreasing the inlet width to 30% of the pond width can successfully improve the performance of the pond.

Sustainable Management of Sediment Retention Ponds to Mitigate Degradation of Coastal Fisheries and Ecosystem: The Case of Ishigaki Island, Okinawa, Japan

Sustainable Management of Sediment Retention Ponds to Mitigate Degradation of Coastal Fisheries and Ecosystem: The Case of Ishigaki Island, Okinawa, Japan

Arsenic-Imposed Effects on Schwertmannite and Jarosite Formation in Acid Mine Drainage and Coupled Impacts on Arsenic Mobility

This study explores interactions between As and Fe(III) minerals, predominantly schwertmannite and jarosite, in acid mine drainage (AMD) via observations at a former mine site combined with mineral formation and transformation experiments. Our objectives were to examine the effect of As on Fe(III) mineralogy in strongly acidic AMD while also considering associated controls on As mobility. AMD at the former mine site was strongly acidic (pH 2.4 to 2.8), with total aqueous Fe and As decreasing down the flow-path from ∼400 to ∼20 mg L–1 and ∼33,000 to ∼150 μg L–1, respectively. This trend was interrupted by a sharp rise in aqueous As(III) and Fe(II) caused by reductive dissolution of As-bearing Fe(III) phases in a sediment retention pond. Attenuation of Fe and As mobility occurred via formation of As(V)-rich schwertmannite, As(V)-rich jarosite, and amorphous ferric arsenate (AFA), resulting in solid-phase As concentrations spanning ∼13 to ∼208 g kg–1. Schwertmannite and jarosite retained As(V) predominantly by structural incorporation involving AsO4-for-SO4 substitution at up to ∼40 and ∼22 mol %, respectively. Arsenic strongly influenced Fe(III) mineral formation, with high As(V) concentrations causing formation of AFA over schwertmannite. Arsenic also strongly influenced Fe(III) mineral evolution over time. In particular, increasing levels of As(V) incorporation within schwertmannite were shown, for the first time, to enhance the transformation of schwertmannite to jarosite. This significant discovery necessitates a re-evaluation of the prevailing paradigm that As(V) retards schwertmannite transformation.

Long-Term Oxbow Lake Trophic State under Agricultural Best Management Practices

A key principle of agricultural best management practices (BMPs) is to improve water quality by reducing agricultural-sourced nutrients and associated eutrophication. Long-term (1998–2016) lake summer trophic state index (TSI) trends of an agricultural watershed with agricultural best management practices (BMPs) were assessed. Structural BMPs included vegetative buffers, conservation tillage, conservation reserve, a constructed wetland, and a sediment retention pond. TSI included Secchi visibility (SD), chlorophyll a (Chl), total phosphorus (TP), and total nitrogen (TN). Summer TSI 1977 was >80 in 1998–1999 (hypertrophic) and decreased over the first 10 years to TSI 1977 ≈ 75 (eutrophic). TSI 1977 decrease and changing TSI deviations coincided with vegetative buffers, conservation tillage, and conservation reserve. The TSI(SD) decrease (>90 to <70) coincided with vegetative buffers and TSI(TP) decrease (>90 to <75) coincided primarily with conservation tillage and the sediment retention pond. TSI(Chl) increase (<60 to >70) coincided with conservation tillage and vegetative buffer. Results indicate watershed-wide BMPs can modestly decrease summer trophic state through increased water transparency and decreased TP, but these changes are off-set by increases in chlorophyll a to reach a new stable state within a decade. Future research should assess algal nutrient thresholds, internal nutrient loading, and climate change effects.

Assessing multi-scale effects of natural water retention measures on in-stream fine bed material deposits with a modeling cascade

Natural water retention measures (NWRMs) belong to the broad range of nature-based solutions and are receiving increased attention for targeting environmental problems of river catchments as they effectively support the restoration of natural processes and cycles. Challenges involved in NWRMs planning include the development of tools able to project and diagnose the effects at different spatial scales (e.g., catchment or the reach). This paper focuses on NWRMs addressing fine bed material deposits (FBMDs), with the aim of a) assessing factors and scales that control FBMDs; b) simulating the cascading impact of NWRMs on catchment hydrology, sediment loads, reach hydraulics, and FBMD; and c) assessing the effectiveness of NWRMs in targeting FBMDs at different spatial scales (catchment and reach). A modeling cascade was used to propagate the effects. This included a hydrological model (SWAT), a hydraulic model (HEC-RAS), and a spatially distributed Random Forest ensemble to model FBMDs risk for the Aist catchment (650 km2) Austria. Our results show that upstream sediment loads are an important predictor controlling the likelihood of sites to be classified as low risk. The effectiveness of NWRMs in reducing FBMDs is variable and depends on the target risk class. Vegetated filter strips that can trap sediments before they enter into the stream are more effective in increasing the extent of the river network towards natural conditions (5% increase compared to baseline). Sediment retention ponds are effective in reducing the extent of reaches where instream habitats are completely clogged by FBMDs (−8%). Hydromorphological improvements are effective in targeting sites where FBMDs are transported even during mean flow (−10%). A combination of NWRMs could benefit both high-risk as well as low-risk sites. The effectiveness of NWRMs can greatly differ when both reach and catchment diagnostics are analyzed. Thus, multi-scale assessment of the effectiveness can support NWRMs planning by unraveling all the potential benefits and highlighting tradeoffs hidden by analyses limited to a single spatial scale.

Experimental investigation of the effect of temperature differentials on hydraulic performance and flow pattern of a sediment retention pond.

Existing studies on sediment retention ponds (SRPs) have examined the effects of pond layout, inlet and outlet geometry and the installation of baffles on the performance of the SRPs. However, the effects of a temperature difference between the ambient water in the pond and the inflow are often neglected, and the buoyancy forces arising from these differences in temperature can potentially change the flow in the pond and hence its hydraulic performance. This study has experimentally evaluated the effect of these temperature differences on the flow field and residence time in a retention pond for a range of temperature differences. As expected a cold inflow sinks to the bottom of the pond while a hot inflow remains at the surface, but in both cases the inflow flows more rapidly towards the outlet than is the case for isothermal inflow. A counter-current was observed at the bottom or the surface of the pond for colder or hotter influents, respectively. These thermally induced flows significantly reduced the residence time of the pond, reducing the hydraulic performance of the pond and causing severe short-circuiting. The results have also shown that the temperature differences in the pond decrease with time, yet small temperature differences persist with the pond remaining thermally stratified.

Effectiveness of Integrated Best Management Practices on Mitigation of Atrazine and Metolachlor in an Agricultural Lake Watershed.

The study examined the influence of land-use (cropping patterns) and integrated agricultural best management practices (BMPs) on spring herbicide levels in an agricultural watershed. Atrazine and metolachlor were applied for weed control during spring of 1998-2002, 2005, and 2007-2013. Watershed-wide mass of applied herbicides ranged from 12.7 to 209.2g atrazine and 10.9-302.2g metolachlor with greatest application during 1998, 2009-2010 (atrazine) and 2007-2013 (metolachlor). Spring herbicide concentrations in Beasley Lake water ranged from below detection to 3.54μg atrazine/L and 3.01μg metolachlor/L. Multiple linear regression analyses with cropping patterns, BMPs, rainfall and time as independent variables, showed atrazine applications were associated with increases in cotton acreage and quail buffer, while metolachlor applications increased over time. Multiple linear regressions showed lake atrazine concentrations were associated with conservation tillage, rainfall, and corn, while lake metolachlor concentrations were associated with the cumulative metolachlor application and sediment retention pond installation.

Effect of baffles on the hydraulic performance of sediment retention ponds.

An investigation of the effect of baffles on retention pond performance using a physical model of an existing sediment retention pond is presented. Analysis of residence time (RTD curves) was used to compare the hydraulic performance of different arrangements of baffles in the pond. Five different arrangements for the design of baffles were studied. The results show that placing a single baffle to deflect the influent to a sediment retention pond does not improve pond performance; rather, it stimulates short-circuiting. This is contradictory to the literature and is considered to be a consequence of the model pond incorporating sloping walls, which is a novel aspect of this study. Most of the previous studies have neglected the effects of battered walls. Conversely, the inclusion of more than two baffles was found to increase the hydraulic performance. The results reported here are limited to small and narrow ponds where a large portion of the pond is batter (i.e. made up of sloping walls). For large area ponds, batter effects may be negligible and are likely to be different from those reported here.

Evaluation of hydraulic performance indices for retention ponds

Comprehensive hydraulic analysis of sediment retention ponds is commonly achieved through interpretation of residence time distribution and derivation of indices associated with short-circuiting and mixing. However, the availability of various indices indicates the need for careful selection of the most appropriate indices. This study compares some of the commonly used hydraulic performance indices, together with a new short-circuiting index, τ5, for five different flow regimes in a model sediment retention pond. The results show that τ5 was the best measure for short-circuiting. Among the mixing indices, only the Morril index correctly represented the physical behaviour of the experiments. In addition, two hydraulic efficiency indices, λ and a moment index (MI) were assessed and showed a good correlation with the short-circuiting and mixing indices, but MI was more reproducible than λ. Based on these results, this study recommends using τ5, Morril index and MI for analysis of hydraulic performance in sediment retention ponds.

The effect of different baffles on hydraulic performance of a sediment retention pond

Baffles have been utilised in the ponds and wetland to improve the rate of treatment for the polluted water. However, there is limited research in the optimum configuration and type of baffles for sediment retention ponds (SRP). In this study, the effect of porous and submerged solid baffles on the hydraulic performance of a model SRP is assessed. In order to optimise the type and configuration of baffles, several configurations were tested with four different metal meshes (with different aperture size and open area) as porous baffles, and acrylic sheets as solid baffles. The porous baffles were more effective in increasing the retention time and improving the overall hydraulic performance than the solid baffles. The finest mesh with 0.415mm aperture size and 40% open area had the highest performance for most of the configurations with 3 or less baffles. However, for four and five baffles, the medium-fine mesh with 1mm aperture size and 42% open area was the best. For three porous baffles, they were more effective when installed in the first half of the pond compared with when installed about the middle point of the pond, regardless of the mesh size. The two porous baffles with same aperture sizes but different open areas had different hydraulic performance which highlights the importance of mesh aperture in addition to the total open area.

Numerical Simulation of Turbulence-Induced Flocculation and Sedimentation in a Flocculant-Aided Sediment Retention Pond

A model combining multi-dimensional discretized population balance equations with a computational fluid dynamics simulation (CFD-DPBE model) was developed and applied to simulate turbulent flocculation and sedimentation processes in sediment retention basins. Computation fluid dynamics and the discretized population balance equations were solved to generate steady state flow field data and simulate flocculation and sedimentation processes in a sequential manner. Up-to-date numerical algorithms, such as opera tor splitting and LeVeque flux-corrected upwind schemes, were applied to cope with the computational demands caused by complexity and nonlinearity of the population balance equations and the instability caused by advection-dominated transport. In a modeling and simulation study with a two-dimensional simplified pond system, applicability of the CFD-DPBE model was demonstrated by tracking mass balances and floc size evolutions and by examining particle/floc size and solid concentration distributions. Thus, the CFD-DPBE model may be used as a valuable simulation tool for natural and engineered flocculation and sedimentation systems as well as for flocculant-aided sediment retention ponds.

Toxicity Evaluation of Diazinon Contaminated Leaf Litter

Diazinon (O,O-diethyl O-[2-isopropyl-6-methyl-4pyrimid-inyl] phosphothiate) is an organophosphate pesticide withwidespread use on a variety of agricultural crops, such asfruit trees, corn, and tobacco (Burkepile et al., 2000).Approximately 6 million kg of diazinon are appliedannually in the United States and, as a result, are a potentialcontributer to nonpoint source contamination of aquaticenvironments (Banks et al., 2003). Within these aquaticenvironments, decaying plant materials and leaf litter canbe a prominent physical feature, especially during autumn(Webster and Benfield, 1986; Federle and Ventullo, 1990).These materials have extensive surface areas conducive tosorption of soluble organic contaminants (Pierce et al.,1977). This allows for the potential entry of these com-pounds into detrital food webs (Odum and Drifmeyer,1978) resulting in potential effects on aquatic ecosystems(Forrow and Maltby, 2000).Despite the extensive presence of detrital materialwithin some aquatic systems, such as wetlands, marshes,small streams, and heavily canopied rivers, ponds, andlakes, limited research or information exists on the influ-ence of pesticide-contaminated detritus on aquatic eco-systems (Odum et al., 1969; Swift et al., 1988; Harrahyet al., 1994). With increasing use of constructed wetlandsto mitigate nonpoint source contamination, there is agrowing need to assess the role of detritus in understandingthe fate and effects of various contaminants on nontargetaquatic organisms.This study presents an assessment of leaf litter con-tamination in a constucted wetland and a toxicity evalua-tion using a standard laboratory bioassay with thefreshwater test organism, Hyalella azteca Saussure.Materials and MethodsLeaf litter was simulated using postabcission Norwaymaple leaves (Acer platanoides) contained within polyesterbags having 0.5 cm diameter mesh openings. Approxi-mately 20 g (dry weight) of leaf litter was added to eachbag, and approximately 25 g of stainless steel weights wereadded to prevent floating and to ensure all leaf litter re-mained submerged. Five leaf-litter bags were placed to-gether in the center of each of three cells within aconstructed wetland designed for the mitigation of agri-cultural contaminant runoff (e.g., sediment, pesticides,nutrients, etc.). Wetland cells included a sediment retentionpond (SRP), primary wetland cell (1 cell), and a secondary(2 , finishing) wetland cell located adjacent to BeasleyLake in Sunflower County, Mississippi, USA. The con-structed wetland was dosed with 0.16 mg/L diazinon (ac-tive ingredient) as Diazinon 4E , and 403 mg/L suspendedsediment (as a carrier), simulating a 1.3-cm rainfall eventand runoff from a 14 ha agricultural field. Rainfall eventwas based on climatological data from the Beasley Lakeweather station, whereas the contributing area (14 ha) is theactual drainage area feeding the constructed wetland. Oneleaf-litter bag was collected from each wetland cell at 8 h,48 h, 7 d, 15 d, and 27 d after initial dosing.Upon collection, leaf-litter samples were dried and ana-lyzed for diazinon within 48 h after drying. Analyticalchemistry was conducted according to Bennett et al. (2000),using a Hewlett-Packard 6890 gas chromatograph (SantaClara, California,USA) equipped with dual HP 7683 ALS

SEDIMENT CAPTURE EFFECTIVENESS OF VARIOUS BAFFLE TYPES IN A SEDIMENT RETENTION POND

The relative sediment trapping effectiveness of a permanent-pool sediment retention pond was assessed due to theinstallation of baffles composed of different materials commonly used on construction sites. A suite of experiments wasperformed at the Sediment and Erosion Control Research and Education Facility (SECREF) at North Carolina StateUniversity in which an acoustic Doppler velocimeter was used to record steady-state flow velocity data at 50 grid points withinthe pond at three steady input flow rates. Hydrodynamic data were taken for free flow and for three different baffle materials:jute germination blanket backed by coir fiber, standard tree protection fence, folded and tied together into three layers toreduce pore size, and standard silt fabric with weirs. The experiments were conducted with a characterized soil injectedupstream at a fixed rate with sampling at the outlet. At the completion of each baffle experiment, particle size distributionwas determined for sediment deposits at fixed points in the pond bed. Analysis of the hydrodynamic data suggests that allbaffles greatly reduced and diffused flow compared to an open pond. The jute/coir baffle outperformed a standard silt fencewith weirs and a triple layer of tree protection fence. Results from soil composition analysis and exit turbidity measurementsper baffle configuration confirmed that the jute/coir baffle was the most effective in improving sediment retention in the pond.

Evaluating the impact of watershed management scenarios on changes in sediment delivery to rivers?

High loads of suspended sediment derived from surface water erosion processes are a major source of environmental and economic problems throughout the world. In many places, a reduction in the amount of sediment delivered from arable land to rivers has therefore become a major issue in environmental policy. In Flanders (Belgium), policy makers would like to achieve a reduction in soil erosion and sediment delivery through the use of various control measures adopted under an integrated environmental watershed management program. A distributed modelling approach (SEDEM/WaTEM) showed that although end-of-the-pipe solutions such as buffer strips or sediment retention ponds have a direct impact on sediment delivery, on-site soil conservation measures were more effective in reducing sediment loads in rivers. It remains questionable, however, whether the significant impact that watershed management has on local sediment yields, can be extrapolated to larger river drainage basins. In the case of highly regulated and channelized rivers, the impact may be much higher compared to natural rivers.

Sediments and sediment-derived soils in Illinois: pedological and agronomic assessment.

Dredging sediments from water bodies in Illinois is done to preserve reservoir capacity, maintain navigation and recreation channels, and restore habitats, but the fate of the sediments is an issue. In anticipation of a major sediment dredging operation in Lake Peoria in the Illinois River, a retrospective study of sediment placement operations was performed. Sediments previously dredged from reservoirs and placed in retaining ponds were sampled along with adjacent upland soils which served as references. Sediments from the Illinois River above Peoria were sampled from islands, river bottom, and adjacent floodplain. Dredged sediment retention ponds initially support wetland vegetation. After dewatering, the physical properties of sediments tend to become similar to upland soils and the retention basins are then able to support conventional agriculture. Sediment organic matter content was similar to local reference surface soils, and soil pH of the sediments was neutral or above. Sediment textures are dominated by silts and clays, with the Lake Peoria samples being most clayey. Calcium was the dominant cation in all the samples, and micronutrients measured were in adequate supply for plant growth. However, because the Illinois River watershed includes industrial inputs, river sediments contained elevated levels of some metals, but they were generally below levels of regulatory concern. Results indicated that properly handled dredge sediments could make high quality agricultural soils. In addition, sediment placement on poor soils could improve their productivity.

Anthropogenic marker evidence for accelerated sedimentation in Lake Illawarra, New South Wales, Australia

The chronology of near-surface sediments in Lake Illawarra has been investigated using radiocarbon dating and anthropogenically derived substances including trace metals, ash, and137Cs. Sediments at depths about 1 m below the water-sediment interface ranged in age from Modern to 786 calendar years bp on the basis of radiocarbon dating ofNotospisula trigonella valves. Multiple marker (for example ash-trace metals) depth-concentration sediment profiles yielded estimates of sedimentation rate ranging from 3 to 5 mm yr−1 at Griffins Bay to more than 16 mm yr−1 at Macquarie Rivulet. Sedimentation rates of approximately 10 mm yr−1 appeared to be typical of the western and southwestern portions of the lagoon. Rates of sediment accretion, prior to catchment clearing, urbanization, and industrialization have been estimated at less than 1 mm yr−1, thus indicating a general tenfold increase in sediment accumulation adjacent to the western foreshore caused by catchment development. Accelerated sedimentation in shallow coastal lagoons constitutes significant environmental impacts including shoaling, degradation of seagrass beds, and increased turbidity with consequent loss of aesthetic appeal. Management policy should be directed at attempts to reduce the amount of sediment input by the construction of strategically placed sediment retention ponds. Siltation within the shallow embayments of Lake Illawarra could be ameliorated by a carefully planned program of dredging.

Ponding Surface Drainage Water for Sediment and Phosphorus Removal

ABSTRACT SEDIMENT and phosphorus (P) removal efficencies of a sediment-retention pond with a capacity of about 3400 m3 receiving surface water runoff from 4050 ha of irrigated land, were measured for five years. Average daily flow through the pond, during the irrigation runoff period, was 347 L/s, with a pond retention time of 2.7 h. The pond removed 65 to 76 percent of the sediment, and 25 to 33 percent of the total P entering the pond. Sedi-ment and phosphorus removal efficiencies depended upon the flow rate and the sediment concentration of surface return flow entering the pond. Sediment and phosphorus were most efficiently removed when the stream flow was 340 to 453 L/s and the sediment concen-tration was in the range of 20 to 750 mg/L. Sediment removed from the pond was used to cover protruding basalt to improve and expand a golf course.

Irrigation Water Salt Concentration Influences on Sediment Removal by Ponds

AbstractIrrigation water salt concentration effects on sediment pond efficiency were investigated to demonstrate the necessity of considering the salt concentration in the irrigation waters when designing sediment retention ponds. The influence of dissolved salt was determined by adding concentrated CaCl2 solutions to three ponds and then measuring electrical conductivities and sediment concentrations at the pond outlets. Increasing the salt concentration increased the sediment removal efficiencies when the retention time in the pond exceeded 1 hour or the inflow sediment concentration exceeded 500 ppm for the three soils studied. Adding salt to laboratory soil sample suspensions increased the settling rates for the two soils studied. That data indicate that the salt concentration in irrigation water is an important factor in determining sediment pond size and retention time. Using pond design criteria obtained from sediment ponds receiving water of a given salt concentration to design ponds that will receive water with a different salt concentration should include adjustments for salt concentration differences. A simple laboratory test is suggested to predict which soils will respond to irrigation water salt concentration changes that are likely to result in sediment pond efficiency changes.

Sediment in Irrigation and Drainage Waters and Sediment Inputs and Outputs for Two Large Tracts in Southern Idaho

AbstractSediment inputs from Snake River irrigation water and sediment losses back to the river were measured for two large irrigated tracts in southern Idaho. There was a net sediment accumulation of 0.69 metric tons/ha onto the 65,000 ha Northside tract but a net sediment loss of 0.46 metric tons/ha from the 82,000 Twin Falls tract. Differences in sediment losses from the two tracts result from the difference in sedimentation in the drain‐ways of the two projects. Sediment deposited in drains on the Northside tract amounted to 4.5 metric tons/ha compared to 0.95 metric tons/ha for the Twin Falls tract. Drains on the Northside tract were constructed to grade whereas most drains on the Twin Falls tract are natural channels with steeper gradients. The net amounts of sediment eroded from farms within each tract were 4.0 metric tons/ha for the Northside tract and 1.42 metric tons/ha for the Twin Falls tract. This erosion loss from farms could be reduced within each tract by more careful use of water and construction of on‐farm sediment retention ponds. This would also reduce the amount of sediment returned to the river and lower costs of mechanically removing sediment from drains and canals. Construction of sediment retention ponds along main drains and reducing the amount of surface runoff returning to the river would also reduce the amount of sediment returning.