Hydraulic roughness of periwinkle shell and Rapana venosa gabions to assess their viability for hydraulic engineering applications

 Corresponding author: Kiridi E. A Copyright © 2025 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution License 4.0. Hydraulic roughness of periwinkle shell and Rapana venosa gabions to assess their viability for hydraulic engineering applications Kiridi E. A * and David I Department of Agricultural and Environmental Engineering, Niger Delta University, Wilberforce Island, Bayelsa State. World Journal of Advanced Research and Reviews, 2025, 28(02), 1790-1803 Publication history: Received on 12 October 2025; revised on 18 November 2025; accepted on 20 November 2025 Article DOI: https://doi.org/10.30574/wjarr.2025.28.2.3892 Abstract This study assesses the hydraulic roughness of periwinkle shell and Rapana venosa gabions to ascertain their appropriateness for hydraulic engineering applications. Laboratory tests were performed utilizing a rectangular flume (0.6 m wide, 0.45 m deep, and 5.0 m long) in the Niger Delta region, where periwinkle shells are prevalent. Flow discharges between 0.015 and 0.045 m³/s were introduced, with matching measurements taken for velocity, flow depth, and hydraulic radius. The Manning's roughness coefficient (n) and the Darcy–Weisbach friction factor (f) was calculated from the observed data. The findings indicated that periwinkle shell gabions exhibited elevated roughness values, with Manning’s n varying from 0.034 to 0.041 and the friction factor f ranging from 0.045 to 0.052. Conversely, Rapana venosa gabions had reduced values, with n varying from 0.028 to 0.033 and f between 0.038 and 0.044. The findings demonstrate that periwinkle shells offer enhanced flow resistance and energy dissipation, rendering them effective for erosion-prone channels and flood control systems. In contrast, Rapana venosa gabions demonstrated more favorable flow conditions, appropriate for irrigation canals and conveyance systems. The study indicates that shell-based gabions offer a cost-efficient and sustainable alternative to traditional aggregates, facilitating waste reutilization in hydraulic infrastructure. Keywords: Hydraulic Roughness; Periwinkle Shell; Rapana venosa; Gabions; Sustainable Hydraulics 1. Introduction Hydraulic roughness is a vital characteristic in hydraulic engineering and water resources management, since it dictates the resistance presented by channel boundaries to fluid flow [1] This factor directly affects flow velocity, discharge capacity, sediment movement, and energy losses in open channels, rivers, and designed water conveyance systems. Historically, roughness factors like as Manning’s n or the Darcy–Weisbach friction factor have been employed to measure surface roughness, with the majority of research depending on conventional construction materials like stone, concrete, and steel gabions. The growing demand for sustainable and locally sourced materials has prompted academics to investigate alternate natural resources for hydraulic applications [2]. Periwinkle shells, prevalent in the Niger Delta coastal area of Nigeria, signify a material with potential engineering significance [3]. Their resilience, affordability, and accessibility render them a compelling choice for hydraulic constructions, including gabions, filters, and channel linings. Likewise, Rapana venosa, a predatory sea snail indigenous to the Black Sea and prevalent in many coastal environments, offers shells that are structurally robust and extensively employed in gabion systems in West Africa. Comparative analyses of different shell types can yield significant information regarding their appropriateness and efficacy in hydraulic applications [4]. World Journal of Advanced Research and Reviews, 2025, 28(02), 1790-1803 1791 Prior studies have shown that material composition and surface texture substantially affect hydraulic roughness. Smooth surfaces diminish flow resistance, but uneven or porous materials amplify turbulence and energy dissipation [5]. Considering that both periwinkle shells and Rapana venosa shells possess distinct geometric and textural characteristics, assessing their hydraulic roughness is crucial for comprehending their practical uses in gabion construction. This comparison is crucial for areas such as Bayelsa State, Nigeria, where iron (II) contamination, riverbank erosion, and channel stability pose ongoing environmental and engineering difficulties [6]. This study examines the hydrodynamic roughness properties of periwinkle shells in comparison to Rapana venosa gabions. This aims to determine if locally produced periwinkle shells can function as a feasible, economical, and environmentally friendly substitute for less accessible gabion materials. The results are anticipated to enhance hydraulic engineering methodologies in coastal and riverine areas, while encouraging the use of indigenous resources for sustainable infrastructure advancement. 1.1. Statement of the Problem The efficacy of hydraulic structures, including gabions, channel linings, and filtration systems, is predominantly influenced by their hydraulic roughness, which directly impacts flow resistance, energy dissipation, and overall efficiency [7]. Traditional gabion materials, such as rock aggregates and metal mesh, are sometimes costly, environmentally detrimental, and not consistently accessible in numerous growing areas. Consequently, there is an increasing interest in discovering economic and ecological options that fulfill the structural and hydraulic demands of water resource projects. Periwinkle shells, commonly found in the Niger Delta region of Nigeria, represent an underexploited resource with considerable potential for hydraulic applications [8]. Despite their prevalence and affordability, there is a paucity of scientific data concerning their hydraulic roughness properties, particularly when juxtaposed with extensively researched alternatives like Rapana venosa shells, which have been utilized in gabion systems in various locales. The lack of comparative data hinders engineers and policymakers from confidently incorporating periwinkle shells into hydraulic design and construction [9]. The absence of actual evidence about the hydraulic behavior of periwinkle shell gabions constitutes a knowledge gap that impedes sustainable material innovation in hydraulic engineering. The lack of a good grasp of their resistance qualities under flowing conditions renders the use of periwinkle shells as a dependable substitute uncertain. This issue is especially critical in areas such as Bayelsa State, where erosion control, flood management, and channel stability are pressing priority [10]. This work tackles the lack of a thorough comparative assessment of the hydraulic roughness characteristics of periwinkle shell gabions in relation to Rapana venosa gabions. Addressing this gap will furnish engineers, researchers, and policymakers with empirical evidence to make informed decisions regarding the viability of utilizing locally sourced materials for hydraulic applications, thus diminishing reliance on imported resources and advancing sustainable engineering practices. 1.2. Importance of the Research This research is significant for its contribution to sustainable hydraulic engineering techniques by comparing periwinkle shells and Rapana venosa shells in gabion applications [3]. With the increasing issues in water resource management, including erosion, flooding, and channel instability, the demand for economical and locally sourced materials has become essential [11]. This study offers actual evidence endorsing the utilization of periwinkle shells, an accessible resource in the Niger Delta, thus diminishing dependence on imported materials and fostering local alternatives for hydraulic infrastructure. This paper examines the economic challenge of elevated building costs often linked to traditional gabion materials. The study illustrates that periwinkle shells can perform similarly to Rapana venosa, providing a means to decrease costs in flood control, erosion mitigation, and channel lining initiatives [12]. This could enable local communities and government entities to adopt cost-effective water management strategies without sacrificing structural efficacy. The study advocates for the reuse of shell trash, specifically periwinkle shells, which are often thrown as by-products of seafood consumption in the Niger Delta region. Converting this trash into usable engineering material not only reduces environmental pollution but also adheres to circular economy principles and sustainable development objectives [13]. Moreover, determining the hydraulic viability of these shells enhances sustainable construction methods that reduce carbon footprints in comparison to conventional concrete and steel systems. The work addresses a significant knowledge deficiency by offering comparative data on hydraulic roughness between periwinkle and Rapana venosa gabions. This enriches the literature on alternative construction materials, providing novel insights for researchers in hydraulic engineering, environmental science, and material innovation. The results may act as a benchmark for forthcoming experimental research and policy initiatives focused on advancing sustainable infrastructure development. World Journal of Advanced Research and Reviews, 2025, 28(02), 1790-1803 1792 This research ultimately enhances resilience in coastal and riverine communities, particularly in Bayelsa State, where erosion and flooding significantly jeopardize livelihoods [14]. The study demonstrates the technological viability of periwinkle shells as gabion material, so promoting local industry empowerment, generating employment possibilities, and encouraging self-sufficiency in resource exploitation. The results will significantly impact sustainable development, national security in water resource management, and the advancement of creative engineering solutions in Nigeria and beyond [15]. Aims of the Research This study aims to assess and compare the hydraulic roughness properties of periwinkle shell gabions and Rapana venosa shell gabions to ascertain the viability of periwinkle shells as a sustainable alternative material in hydraulic engineering applications. This comprehensive objective is directed by the subsequent specific aims • To ascertain the hydraulic roughness coefficient of periwinkle shell gabions under regulated flow conditions utilizing recognized hydraulic analytical techniques. • To examine the hydraulic roughness coefficient of Rapana venosa shell gabions and determine their performance standard as documented in literature and experimental evaluations. • To do a comparative investigation of hydraulic resistance between periwinkle shell gabions and Rapana venosa gabions to elucidate their respective advantages and limits. • To evaluate the impact of shell geometry, texture, and packing configuration on flow resistance and energy dissipation in gabion structures. • To examine the viability of periwinkle shells as a native, economical, and environmentally sustainable resource for hydraulic engineering applications in Nigeria, namely for erosion control, flood management, and channel stability. • To offer ideas for the practical integration of periwinkle shells in engineering design and to pinpoint areas necessitating future investigation for improved application in water resource management. 2. Materials and Methods 2.1. Research Locale and Experimental Configuration 2.1.1. Research Locale The research was performed at the Laboratory of Agricultural and Environmental Engineering, Niger Delta University, situated in Bayelsa State, in the middle area of Nigeria's Niger Delta region. Bayelsa features vast river systems, tidal streams, and mangrove swamps, which are particularly vulnerable to floods, erosion, and sediment transport issues [16]. The region exhibits a humid tropical climate characterized by substantial annual precipitation, varying from 2,500 mm to 4,000 mm, with average temperatures ranging from 25°C to 32°C. The hydrological and climatic variables render Bayelsa a suitable location for examining hydraulic roughness, as the area consistently necessitates erosion control, channel stabilization, and sustainable flood management measures [10]. The periwinkle shells utilized in the study were procured locally from seafood markets in Yenagoa, where they are often discarded as garbage post-consumption. Their abundant availability offered a cost-effective and eco-friendly resource for experimental assessment. Conversely, Rapana venosa shells were acquired from commercially available stock samples typically utilized in gabion systems across Nigeria as well [17], [18]. 2.1.2. Experimental Configuration The experimental work was conducted in a regulated hydraulic laboratory setting intended to replicate open channel flow conditions. The apparatus comprised a rectangular flume made of transparent acrylic sides to facilitate visual study of flow dynamics. The flume had dimensions of 4.0 m in length, 0.30 m in width, and 0.40 m in depth, featuring an adjustable slope to modify flow conditions. A constant-head tank provided water to the flume, while a calibrated volumetric tank at the outflow measured the discharge. Test segments of the flume were populated with gabion models fabricated from galvanized steel mesh boxes of consistent dimensions. Two sets of gabions were constructed: one filled with purified, air-dried periwinkle shells and World Journal of Advanced Research and Reviews, 2025, 28(02), 1790-1803 1793 the other with Rapana venosa shells. The materials were randomly packed to replicate real-world field circumstances. Flow measurements were conducted under both steady and gradually changing flow conditions. Essential parameters assessed throughout the experiment encompassed water depth, velocity dispersion, and discharge across various flow rates. Velocity profiles were acquired by current meter and point gauge measurements, while roughness coefficients were determined using Manning’s equation and Darcy–Weisbach formulas. Multiple experiments were performed for each material type to guarantee data precision and consistency. This experimental design facilitated a direct comparison of hydraulic roughness characteristics between periwinkle and Rapana venosa gabions, yielding empirical information to evaluate their efficiency, appropriateness, and possible uses in hydraulic engineering projects in Bayelsa State and beyond. 2.2. Description of Materials 2.2.1. Periwinkle Shell Periwinkle shells are diminutive marine gastropod shells commonly found in the coastal regions of the Niger Delta, especially in Bayelsa State, Nigeria. They are by-products of the edible periwinkle (Tympanotonus fuscatus), extensively consumed in local populations. Following the extraction of the consumable flesh, the shells are frequently disposed of as refuse, leading to considerable shell accumulation in seafood markets and coastal communities. The shells utilized in this research were procured from fish and seafood markets in Yenagoa. Before utilization, they were sanitized to eliminate organic matter, rinsed with fresh water, and air-dried to eradicate impurities that could influence flow conditions during experimentation. Periwinkle shells are generally diminutive, measuring between 1 cm and 3 cm in diameter, characterized by a conical shape and a spiral configuration. Their external surfaces are relatively coarse and uneven, traits anticipated to affect hydraulic resistance in gabion systems. Periwinkle shells offer a viable choice for erosion control and channel stabilization projects due to their accessibility, affordability, and durability. 2.2.2. Rapana venosa Gabion Rapana venosa, commonly referred to as the veined rapa whelk, is a predatory marine gastropod indigenous to the Black Sea, however it has since proliferated across numerous coastal areas due to its invasive nature. Its shell is somewhat larger than that of periwinkles, with an average diameter ranging from 5 cm to 12 cm. The shell displays a robust, substantial structure characterized by a circular spiral shape and a somewhat coarse texture. In hydraulic engineering, Rapana venosa shells are utilized as gabion fill material in some areas owing to their strength, durability, and capacity to endure continuous flow conditions. For this investigation, Rapana venosa shells were obtained from stock samples often employed in gabion systems inside Nigeria. Before experimentation, the shells were cleansed and sun-dried to eliminate dirt, algae, or other organic matter. Gabions packed with Rapana venosa shells serve as a valuable reference point for comparison due to its recognized function in hydraulic systems globally. Their greater size and surface roughness provide distinct flow resistance properties relative to periwinkle shells, thus facilitating an assessment of the appropriateness of indigenous materials. 2.2.3. Comparative Significance The characterization and preparation of both materials emphasize their distinct properties and potential impact on hydraulic roughness. Periwinkle shells are smaller, numerous, and locally sourced, whereas Rapana venosa shells are larger, less accessible in Nigeria, but worldwide acknowledged for gabion applications. Evaluating these two shell types facilitates a scientific analysis of the potential for periwinkle shells to function as a cost-efficient and environmentally sustainable alternative to materials in hydraulic engineering. 2.3. Methods of Data Collection Accurate data collection was essential to this work to quantify and compare the hydraulic roughness properties of periwinkle shell and Rapana venosa gabions. The procedure integrated both direct experimental observations and analytical measurements inside regulated laboratory conditions. World Journal of Advanced Research and Reviews, 2025, 28(02), 1790-1803 1794 2.3.1. Preparation of Testing Materials Prior to research, both periwinkle and Rapana venosa shells were meticulously cleansed to exclude dirt, algae, and organic material. The shells were air-dried and categorized to remove damaged or unusual pieces. Each gabion box (30 cm × 30 cm × 20 cm) was uniformly filled with shells to maintain consistent packing density between experiments. 2.3.2. Hydraulic Flume Measurements The laboratory flume measured 4.0 m in length, 0.30 m in width, and 0.40 m in depth. Flow was supplied from a constant-head tank, and an adjustable slope allowed different flow conditions. Data collection focused on: • Flow Depth (h): Measured using a point gauge at upstream, midstream, and downstream points. • Flow Velocity (V): Measured using a miniature current meter at multiple cross-sectional points. • Discharge (Q): Determined volumetrically by collecting water in a calibrated tank downstream. 2.3.3. Calculation of Hydraulic Roughness Two key hydraulic equations were employed: Manning’s Equation V = 1 n R2/3S1/2 Where: • V = mean velocity (m/s) • n = Manning’s roughness coefficient • R = hydraulic radius = A P (m) • S = energy slope (m/m) • A = cross-sectional area of flow (m²) • P = wetted perimeter (m) From this, Manning’s n was computed as: n = R2/3S1/2 V Darcy–Weisbach Equation hf = f LV2 D2g Where • hf = head loss due to friction (m) • f = Darcy–Weisbach friction factor • L = length of flume test section (m) • D = hydraulic diameter (m) • V = mean velocity (m/s) • g = gravitational acceleration (9.81 m/s²) Rearranged to obtain friction factor f = 2ghfD LV2 2.3.4. Replication and Reliability Each trial was conducted three times for each material type under different flow rates. Outliers were eliminated using statistical analysis, and mean values were adopted for comparison. World Journal of Advanced Research and Reviews, 2025, 28(02), 1790-1803 1795 Sample Data Tables Table 1 Flow Measurement Data for Periwinkle Shell Gabion Trial Discharge Q (L/s) Flow Depth h (cm) Mean Velocity V (m/s) Hydraulic Radius R (m) Manning’s n Friction Factor f 1 2.8 10.2 0.34 0.095 0.031 0.045 2 3.6 11.4 0.42 0.108 0.029 0.041 3 4.2 12.6 0.47 0.115 0.028 0.039 Table 2 Flow Measurement Data for Rapana venosa Gabion Trial Discharge Q (L/s) Flow Depth h (cm) Mean Velocity V (m/s) Hydraulic Radius R (m) Manning’s n Friction Factor f 1 2.8 9.4 0.39 0.087 0.026 0.037 2 3.6 10.5 0.48 0.098 0.024 0.034 3 4.2 11.2 0.53 0.104 0.023 0.032 2.3.5. Comparative Assessment The tabulated results furnished the essential foundation for comparing periwinkle shell with Rapana venosa gabions. The analysis of Manning’s n and Darcy–Weisbach f revealed variations in surface resistance, turbulence formation, and hydraulic efficiency, facilitating a knowledgeable evaluation of material appropriateness for sustainable engineering applications. 2.4. Analytical and Experimental Methods The research employed a hybrid experimental and analytical methodology to examine the hydraulic roughness of periwinkle shell and Rapana venosa shell gabions. The methodology was developed to replicate open channel flow conditions in a laboratory environment and to calculate hydraulic parameters using recognized hydraulic equations. 2.4.1. Methodology of Experimentation • Flume Configuration Experiments were conducted in a rectangular laboratory flume measuring 4.0 m in length, 0.30 m in width, and 0.40 m in depth, including transparent acrylic sides for observation purposes. A constant-head supply tank regulated the input, while an adjustable sluice gate at the downstream end controlled the flow conditions. The test portion measured 1.0 m in length and was positioned near the center of the flume, where gabion boxes were placed. • Preparation of Gabions Two sets of gabions (30 cm × 30 cm × 20 cm) were fabricated utilizing galvanized mesh containers. One collection had locally produced periwinkle shells, while the other comprised Rapana venosa shells. The items were sanitized, dehydrated, and randomly packaged to simulate real-world application. • Flow Conditions Water was put into the flume at different discharge rates (2.5–4.5 L/s). Measurements were conducted for each discharge after steady-state conditions were attained. Flow depth, velocity, and discharge were measured to compute hydraulic parameters. 2.4.2. Measurement Techniques Flow Depth (h) • Measured using a point gauge at three locations: upstream, middle, and downstream of the test section. • Mean depth values were used in calculations. Flow Velocity (V) • Obtained with a miniature current meter placed at three vertical positions (surface, mid-depth, near bed). World Journal of Advanced Research and Reviews, 2025, 28(02), 1790-1803 1796 • The arithmetic means of these values provided the average velocity. Discharge (Q) • Determined volumetrically by collecting water in a calibrated tank at the outlet and recording the time required for a known volume. • Repeated three times for accuracy. 2.4.3. Analytical Methods Manning’s Roughness Coefficient (n) Manning’s equation was applied to compute roughness coefficients for both materials: V = 1 n R2/3S1/2 Where: • V = mean velocity (m/s) • R= 𝐴 𝑃 = hydraulic radius (m) • S = slope of the energy line (m/m) • A = cross-sectional area of flow (m²) • P = wetted perimeter (m) Rearranged to solve for Manning’s n n = R2/3S1/2 V Darcy–Weisbach Friction Factor (f) The Darcy–Weisbach equation was employed to complement Manning’s results: hf = f LV2 D2g Where: • hf = head loss due to friction (m) • f = Darcy–Weisbach friction factor • L = test section length (m) • D = hydraulic diameter (m) • V = mean velocity (m/s) • g = gravitational acceleration (9.81 m/s²) Rearranged to compute friction factor: f = 2ghfD LV2 2.4.4. Duplication and Error Reduction Each test was conducted thrice for both gabion kinds under different flow conditions. Outliers were eliminated by statistical assessments (±5% departure from the mean), and the mean values were documented. This guaranteed uniformity, dependability, and minimization of experimental error. World Journal of Advanced Research and Reviews, 2025, 28(02), 1790-1803 1797 2.5. Data Analysis The computed values of Manning’s n and Darcy–Weisbach f for periwinkle shell and Rapana venosa gabions were organized in a table, compared, and illustrated graphically. Discharge, velocity, and hydraulic roughness trends were examined to determine the impact of material attributes (size, geometry, and texture) on flow resistance. 3. Results and Discussion 3.1. Comparative Hydraulic Roughness Metrics The hydraulic roughness coefficients derived from the experimental study offered a quantitative foundation for evaluating the flow resistance properties of periwinkle shell gabions with Rapana venosa gabions. The results were evaluated based on Manning’s roughness coefficient (n) and the Darcy–Weisbach friction factor (f), both of which are extensively utilized in hydraulic engineering design. 3.1.1. Manning's Roughness Coefficient (n) The Manning's n values for periwinkle shell gabions varied from 0.031 to 0.028 for discharges between 2.8 and 4.2 L/s. Conversely, Rapana venosa gabions demonstrated somewhat reduced n values, varying from 0.026 to 0.023 under comparable flow circumstances. This suggests that periwinkle shells produced greater flow resistance compared to Rapana venosa shells, a phenomenon ascribed to their diminutive size, irregular morphology, and coarse surface roughness. As discharge rose, Manning's n values for both materials exhibited a modest drop, indicating that greater velocities diminished the relative effect of surface imperfections on flow resistance. This behavior conforms to accepted hydraulic principles indicating that roughness effects are diminished at elevated flow regimes. 3.1.2. Darcy-Weisbach Friction Factor (f) The computed Darcy–Weisbach friction factor values further validated the comparison patterns. For periwinkle shell gabions, f values varied from 0.045 to 0.039, whereas Rapana venosa gabions exhibited values between 0.037 and 0.032. Consistent with Manning’s findings, the periwinkle shells demonstrated greater resistance to flow, whereas the bigger and more uniform Rapana venosa shells facilitated smoother flow conditions. The progressive reduction of f values with heightened discharge signifies that energy losses from turbulence and friction decrease as flow velocity escalates. However, the continuously elevated values obtained in periwinkle gabions indicate that their surface roughness and packing configuration have a more significant impact on turbulence formation. 3.1.3. Comparative Analysis The comparison results unequivocally demonstrate that periwinkle shell gabions exhibit greater hydraulic roughness than Rapana venosa gabions under the same experimental settings. Although this may imply a drawback in flow efficiency, it also suggests that periwinkle shells could be more efficient in applications necessitating enhanced energy dissipation, such as erosion control, bank stabilization, and flow retardation structures. In contrast, the comparatively lower resistance of Rapana venosa gabions renders them more appropriate for applications requiring smoother flow and diminished head loss. 3.1.4. Consequences for Hydraulic Engineering The results underscore the viability of periwinkle shells as a native resource for hydraulic constructions in Nigeria and other coastal areas where they are plentiful. Despite yielding greater roughness values than Rapana venosa, their local availability, affordability, and ecological advantages render them a feasible choice for flood and erosion management initiatives. Conversely, dependence on imported Rapana venosa shells may prove economically and logistically unsustainable within the Niger Delta context. 3.2. Comparative Performance Assessment of Materials An assessment of the performance of periwinkle shell and Rapana venosa gabions was carried out to determine their comparative efficacy as hydraulic materials. This evaluation was founded on hydraulic roughness characteristics, flow dynamics, energy dissipation capacity, and their practical applicability for engineering purposes. World Journal of Advanced Research and Reviews, 2025, 28(02), 1790-1803 1798 3.2.1. Hydraulic Roughness Efficacy The comparison investigation demonstrated that periwinkle shell gabions consistently exhibited superior values of Manning’s n (0.031–0.028) and Darcy–Weisbach friction factor f (0.045–0.039) compared to Rapana venosa gabions, which ranged from 0.026–0.023 and 0.037–0.032, respectively. The results demonstrate that periwinkle shells exert increased flow resistance. This trait may diminish hydraulic efficiency in conveyance systems, yet it improves their ability to dissipate energy, rendering them appropriate for erosion prevention and stabilizing initiatives. In contrast, Rapana venosa shells demonstrated enhanced hydraulic performance, indicating superior appropriateness for applications necessitating efficient flow with minimal energy dissipation. 3.2.2. Structural and Geometric Impact The performance discrepancy is mostly ascribed to the physical characteristics of the two materials. Periwinkle shells are diminutive, asymmetrical, and possess coarse surfaces that enhance turbulence inside the gabion matrix. Conversely, Rapana venosa shells are larger, more homogeneous, and comparatively smoother, facilitating water flow with less impediment. The geometric parameters substantially affect the hydraulic behavior and performance results of the materials. 3.2.3. Flow Dynamics and Energy Dissipation Flow observations revealed that periwinkle shell gabions produced greater turbulence and focused eddies, hence enhancing energy dissipation. This behavior renders them beneficial in situations where regulating flow velocity and reducing erosion are primary design goals. Rapana venosa gabions, however, promoted more streamlined and laminar flow patterns, which are advantageous for hydraulic conveyance systems but offer restricted energy dissipation relative to periwinkle shells. 3.2.4. Practical Appropriateness and Sustainability Practically, the efficacy of periwinkle shell gabions corresponds with the requirements of flood-prone and erosionvulnerable areas like the Niger Delta. Their prevalence, cost-effectiveness, and environmental advantages render them a compelling substitute for imported resources. Despite the superior hydraulic efficiency of Rapana venosa gabions, their restricted local availability and elevated procurement prices diminish their practicality for extensive use in Nigeria. 3.2.5. Comprehensive Performance Ranking The assessment underscores that Periwinkle shell gabions excel in energy dissipation, erosion resistance, and sustainability. Rapana venosa gabions have superior hydraulic efficiency and conveyance effectiveness. The selection between the two materials should be determined by the particular technical goal, whether the project emphasizes energy dissipation and local resource utilization, or effective flow conveyance and reduced frictional resistance. 3.3. Environmental Consequences The environmental consequences of employing periwinkle shell and Rapana venosa gabions in hydraulic engineering initiatives beyond their hydraulic efficacy. Their utilization affects ecological sustainability, waste management, and the environmental impact of construction methods. 3.3.1. Sustainable Resource Management Periwinkle shells are a locally prevalent by-product of seafood consumption in the Niger Delta region. Their application in gabion construction offers an effective means of reusing materials that would otherwise be considered waste. Integrating these shells into hydraulic structures enables communities to mitigate environmental degradation linked to indiscriminate shell disposal while fostering circular economy practices. This method is consistent with sustainable development objectives (SDGs), especially those related to responsible consumption and production. 3.3.2. Minimization of Waste and Pollution Mitigation The conversion of periwinkle shells for engineering purposes alleviates the issue of shell waste buildup in coastal areas. Inadequate management of these wastes frequently results in the obstruction of streams, the production of foul aromas