Rainwater Ingress Research Articles

Ecotoxicological assessment of sanitary sewer overflows and rainfall dynamics offers insights into conditions for potential adverse ecological outcomes

Sewer overflows are an environmental concern due to their potential to introduce contaminants that can adversely affect downstream aquatic ecosystems. As these overflows can occur during rainfall events, the influence of rainwater ingress from inflow and infiltration on raw untreated wastewater (influent) within the sewer is a critical factor influencing the dilution and toxicity of the contaminants. The Vineyard sewer carrier in the greater city of Sydney, Australia, was selected for an ecotoxicological investigation of a sanitary (separate from stormwater) sewerage system and a wet-weather overflow (WWO). Three influent samples were collected representing dry-weather (DW), intermediate wet-weather (IWW) and wet-weather (WW). In addition, a receiving water sample was also collected downstream in Vineyard Creek (WW-DS) coinciding with a WWO.We employed direct toxicity assessment (DTA) and toxicity identification evaluation (TIE) approaches to gain comprehensive insights into the nature and magnitude of the impact on influent from rainwater ingress into the sewer. Three standard ecotoxicological model species, a microalga, Chlorella vulgaris, the water flea, Ceriodaphnia dubia and the midge larva, Chironomus tepperi were used for both acute and chronic tests. The study revealed variable toxicity responses, with the sample of influent collected in wet-weather displaying lower toxicity compared to the dry-weather sample of influent. Ammonia, and metals, were identified in dry weather as contributors to the observed toxicity, however, this risk was alleviated through rainwater ingress in wet-weather with further dilution within the receiving water. Based on toxicity data, dilutions of influent to minimise effects on C. vulgaris and C. dubia ranged from 1 in 12 in DW to 1 in 2.8 in WW, and further diminished in the receiving water to 1 in 1.8. The successful application of ecotoxicological approaches enabled the assessment of cumulative effects of contaminants in influent, offering valuable insights into the sanitary sewer system under rainwater ingress.

Component-based hurricane vulnerability model for mid/high-rise commercial residential buildings

This paper focuses on the vulnerability of residential mid/high-rise buildings (MHRB) to hurricane-induced wind and wind-driven rain ingress, with a special emphasis on interior and contents damage. A component-based methodology utilizes the physics of rainwater ingress, distribution and propagation to provide the basis for the proposed MHRB risk assessment model. The model combines estimates of wind speed, impinging rain and surface run-off wind driven rain, envelope defects and breaches, interior water distribution and propagation, and component cost analyses to project envelope, interior and contents damage. The paper describes the model, verifies that it satisfies logical relationships to risk, and compares it against existing MHRB models. The new physics-based interior and contents vulnerability model should facilitate the evaluation of the cost effectiveness of mitigation measures.

Advancing Urban Wastewater Management: Optimizing Sewer Performance through Innovative Material Selection for the Armlet with a Wet Circuit Measurement System

Rainwater infiltration presents substantial challenges for urban wastewater management systems. This article delves into enhancing the quality of wastewater systems by proposing a novel device designed to tackle this issue comprehensively. The focal point of our research revolves around the conceptualization, construction, rigorous testing, and the potential multifaceted applications of this innovative wastewater device. Our study is dedicated to assessing the viability of a cutting-edge apparatus that empowers municipal entities in swiftly identifying rainwater ingress points within channels during precipitation events. Our findings vividly showcase the device’s remarkable capability to directly measure moisture levels along the channel’s path, eliminating the arduous need for manual data input, extensive data collection, and intricate water analysis procedures. To ensure the seamless flow of both sewage and water within the sewer channel, the use of a relatively slender strap is conventionally favored. However, factoring in the requisite structural robustness, we recommend a minimum thickness of 4 mm for 3D printing applications. For instances where maintaining the channel’s cross-sectional area integrity is paramount, opting for an armlet with a wet circuit measurement thickness of up to 7 mm is vital. In the realm of material selection, our investigation advocates for the utilization of PC/ABS (polycarbonate/Acrylonitrile Butadiene Styrene), ABS, ASA (Acrylonitrile Styrene Acrylate), or HIPS (High Impact Polystyrene) for strap housing. For sewer diameters surpassing 315 mm, the application of thin-walled PVC (Poly Vinyl Chloride) emerges as a practical recommendation. Notably, the incorporation of PVC flat bars is discouraged, as their presence might potentially hinder the fluidity of sewage flow, thereby compromising the precision of wet circuit measurements. The pivotal innovation lies in the armlet with a wet circuit measurement system, harboring immense potential for broad-scale integration across municipal facilities. This solution emerges as a streamlined and efficient strategy, offering a comprehensive avenue for continuously monitoring, fine-tuning, and optimizing the structural soundness and operational efficacy of sewer systems.

Sedimenty spodního a středního miocénu jihozápadně od Brna ve světle nových poznatků

New knowledge on the occurrence of Lower and Middle Miocene sediments in the southwestern surroundings of Brno has been acquired through geological mapping and documentation work during the recent years. Specific work was focused on: • preparation of the publication on the local national history of the cadastral territory of the village of Bohutice; • salvage study of the former reserved bentonite deposit Ivančice – Réna, which is being gradually remediated and turned into a recreational area; • the area in the foreground of the New Ivančice viaduct, which is susceptible to long-term slope instability; • the western edge of the village of Němčičky near Židlochovice, where extensive construction of family houses is underway; • the area between the municipalities of Moravany, Nebovidy and Ostopovice, where the excavations for new extra-high voltage pylons were documented. The detailed mapping, petrographic and biostratigraphic studies allowed to refine the distribution, lithological characteristics and age of Miocene sediments; specifically, a more extensive occurrence of Lower Miocene sediments compared to previous findings was confirmed (localities Ostopovice, Moravské Bránice – locality 5). These findings support earlier results from the area N of the City of Brno, where the known extent of Ottnangian sediments was expanded at the expense of Badenian sediments. The documentation and sampling of the new excavations (for family houses and extra-high voltage pylons) and old mining pits enabled the description and further study of the sediments. The acquired litho- and biostratigraphic data were correlated with engineering geological findings. In a construction pit in Bohutice, a completely new occurrence of tuffitic sediments of the Ottnangian age was discovered and geochemically verified. Furthermore, the Ottnangian gravels in Němčičky were newly discovered. These contain a large proportion of granitoid pebbles probably derived from the Brno Massif. It was found that the weakly consolidated lithologically variable Lower Miocene sediments are prone to landslides. In the case of the New Ivančice viaduct, extensive suffusion doline were identified, resulting from the ingress of rainwater from the wider area of the railway embankment foreground. Biostratigraphy of the sediments was based on micropaleontological analysis of foraminiferas. Ottnangian sediments were usually fossil- free and/or they contained reworked Cretaceous foraminiferas. Lower Badenian sediments are characterized by occurrence of abundant and diversified fauna represented by foraminifera species such as Martinotiella karreri (Cush.), Globigerinoides bisphericus Todd, Vaginulina legumen (L.), etc.

Interaction of open-top, short, cylindrical tank with wind-driven rain

Driving rain or wind-driven rain (WDR) is defined as rain, falling in an inclined manner due to the driving force of the wind, inflicting damage to the envelope of building, due to rain droplet impingement, hygrothermal effect, and, rain water ingress. When rain is driven by wind, especially high wind (during storm, cyclone, etc.), the rain droplet impact can increase. There is no availability of literatures on the interaction of shell structures with driving rain, which incurs damage to the thin wall of the tank through droplet impact. This scope is the main motivation behind the present study, which is focused on fluid–structure interaction analysis of an open-top, ground-supported, cylindrical tank with a slenderness ratio of 1.0, affected by wind driven rain. The thickness of the tank wall is varied, and, open terrain condition is considered. The study exhibits that the force coefficient (Cf) of WDR is higher between 0° to 53° peripheral position and decreasing upto 140° circumferential location. Maximum 28% increase of force coefficient of WDR noticed for 45° position in comparison to the wind force coefficient. Also, the top of the tank wall exhibits greater deformation and vulnerable under the effect of wind-driven rain load. Also, it is evident that 0° to 18°, and, 0° to 27° circumferential area exhibit higher deformation for radius: thickness (R/t) ratios 500, and 250, respectively. In case of R/t ratios 125, and 166.67, the higher deformation zone is distributed 0° to 15° and 77° to 82° peripherally. This deformation behaviour of the tank wall, shows that the open-top tanks need to be stiffened at the top to withstand the wind-driven rain force. The magnitude of deformation exhibits increments with the decrease in the thickness of wall of the tank. Maximum deformation is observed for lowest thickness of the tank wall.

Analysis of damp in the substructure of a multi-family residential building – case study

This paper discusses dampness in an underground garage of a multi-family residential building on the basis of a case study. Due to high groundwater levels, the building substructure was constructed using W8 watertight concrete. This applies to both the foundation slab and substructure walls. However, leaks have occurred even though the used solutions were in theory designed to protect the building substructure from rainwater ingress. Macroscopic in situ tests, boreholes in the garage hall floor and foundation slab as well as laboratory test to determine the watertightness of the concrete were carried out to determine the cause of this construction defect, manifesting itself as damp in the structural elements in question.

Building Facade Failures due to Rainwater Entry in Turkey

Facade failures due to rainwater entry are common in Turkey although, few systematic studies have been completed to determine the types of defects and failures and their causes as would permit developing appropriate repair solutions. The intent of this study is to determine the types of defects and failures caused by rainwater ingress to building facades based on case studies of failure in Turkey. Thus, defects and failures can be characterized and classified, such that the most common types of failure can be revealed and adequate repair solutions proposed. A review of literature was conducted of studies undertaken in Turkey on rainwater entry and building defects. Additionally, field inspections were carried out for 16 public buildings in Istanbul and information regarding failures was gathered from local authorities. Based on data evaluated from previous research and field inspections, it was determined that majority of the buildings had cladding walls with stucco being the most common cladding material. Failures occurred in cladding facades with stucco included detachment of cladding, staining, and cracks; the most common failure was blistering and exfoliation. Air and rainwater leakage due to defects in sealants was the most common failure in buildings with panel and stick wall systems.

Testing and modeling of hurricane wind-driven rain water ingress, propagation, and subsequent interior damage in residential buildings

Hurricanes are a main cause of economic losses in the world, including Florida. They affect exterior, interior, and the contents of residential buildings. The interior damage can be as much as half of the cost of total damage, but the estimation of the interior damage is still somewhat crude. Most damage models estimate interior damage as a percentage of the exterior damage, or through simple relationships, that relate the height of water ingress in the building to the interior damage. This paper presents a new model for interior and contents damage estimations, which takes into account the physical mechanisms of hurricane-induced interior and contents damage from rainwater ingress. The method incorporates the results of large and full-scale tests to quantify the rainwater propagation and distribution from component to component in the interior of the building, and combines the test results with estimates of water resistance characteristics of the building interior and contents, and with cost analyses. The model is part of the commercial residential low-rise vulnerability model of the Florida Public Hurricane Loss Model (FPHLM). The paper presents the impact of the model on the FPHLM vulnerability curves, and illustrates how the new model can help evaluate mitigation strategies.

P.344 Effects of antidepressants on BDNF levels in patients with major depression: a systematic review

Hurricanes are a main cause of economic losses in the world, including Florida. They affect exterior, interior, and the contents of residential buildings. The interior damage can be as much as half of the cost of total damage, but the estimation of the interior damage is still somewhat crude. Most damage models estimate interior damage as a percentage of the exterior damage, or through simple relationships, that relate the height of water ingress in the building to the interior damage. This paper presents a new model for interior and contents damage estimations, which takes into account the physical mechanisms of hurricane-induced interior and contents damage from rainwater ingress. The method incorporates the results of large and full-scale tests to quantify the rainwater propagation and distribution from component to component in the interior of the building, and combines the test results with estimates of water resistance characteristics of the building interior and contents, and with cost analyses. The model is part of the commercial residential low-rise vulnerability model of the Florida Public Hurricane Loss Model (FPHLM). The paper presents the impact of the model on the FPHLM vulnerability curves, and illustrates how the new model can help evaluate mitigation strategies.

The feasibility of using asphalt concrete with a high percentage of recycled asphalt material in a railway trackbed layer

The use of asphalt concrete (AC) for railway trackbed layers is now well established and, in some countries, even accepted as a standard solution for high–speed or high–load lines. To date constructed track sections which incorporate AC trackbed layers use AC mixtures which contain only up to 30% of reclaimed asphalt (RA). This limit is most likely a remnant of the past when the amount of RA in AC mixtures was limited as a precaution to compensate for the lack of experience with RA. Nowadays, the trend and the aspiration for using higher percentages of RA in AC mixtures is increasing and railway engineering should embrace this. This paper presents the results of ongoing research to this end. The first part of the paper describes a laboratory–based investigation into the required design properties of an AC mixture made of 100% of RA. The second part describes the construction and continuous assessment of a trial section on an operational mainline in the Czech Republic. The results show that it is possible to construct an AC trackbed layer with a high percentage (70%) of RA using only simple mechanization and that such a layer provides an effective formation treatment, significantly reduces the loss of track geometry, provides more uniform track support and protects the subgrade from the adverse effects of temperature changes and the ingress of rainwater. The paper concludes that an AC mixture for a railway trackbed layer should be treated as a specific type of AC mixture, with its own set of design criteria, and invites further research into the feasibility of using AC with high percentage of RA not only as a remediation technique but as a standard trackbed solution.

Design and Performance of an In-Flight Rainfall Simulator in a Geotechnical Centrifuge

The objective of this paper is to present the design details and performance of an actuator for simulating in-flight rainfall at enhanced gravity levels in centrifuge. The developed simulator is capable of inducing in-flight rainfall of various intensities (varying from 10 mm/h to 80 mm/h in prototype dimensions) and durations (over a year continuously in prototype dimensions) on geotechnical structures using specially designed pneumatic nozzles. The intensity and duration of rainfall can be regulated at any point of time in the in-flight condition to replicate prototype natural hazards, ranging from long-term medium intensity rainfall to a short spell of very high intensity rainfall. The various components of the developed simulator are discussed, with special emphasis on measures adopted to nullify Coriolis effects on droplet trajectory. Furthermore, the simulator produces rainfall in the form of fine mist at high gravities, which neutralizes chances of erosion due to impact of raindrops. In the present paper, a total of six calibration tests at high gravities and four centrifuge model tests on a typical silty sand slope were carried out using a 4.5-m radius large beam geotechnical centrifuge facility available at IIT Bombay, India. The analysis and interpretation of calibration results indicated that uniform rainfall intensity could be achieved over entire model surface area, and they were further applied to implement the scaling laws involved in modelling of rainfall in a geotechnical centrifuge. The model tests on silty sand slope indicated a rise in phreatic surface with ingress of rainwater, accompanied by face deformations and surface settlements, which increased in magnitude with higher rainfall intensities. In addition, the phreatic surfaces induced during rainfall using the developed simulator and time corresponding to failure observed in centrifuge were compared with numerical results using Geostudio (2012) and were found to corroborate well.

Estimation of effect of sugarcane bagasse biochar amendment in landfill soil cover on geotechnical properties and landfill gas emission

AbstractIn a sanitary landfill, the final cover plays an important role in reducing the landfill gas emission to the atmosphere and in preventing the ingress of rainwater into the dumped waste. The present study investigated the suitability of sugarcane bagasse biochar as an amendment to the cover soil to improve the required landfill liner properties. The amended cover soil sugarcane bagasse (SSB) was tested for its stability and effectiveness, in terms of both geotechnical properties and methane mitigation efficiency. The effects of amending 15%, 20%, and 25% of sugarcane bagasse biochar (passing through 300 micron Indian Standard sieve) on the geotechnical properties of the SSB indicated that the SSB with 25% biochar showed the required values as per the standard with maximum dry density of 1.57 grams per cubic centimeter (g/cm3), liquid limit, plasticity index, and percentage of fines 48.5%, 16.3%, and 74.7%, respectively, and permeability of 0.9 × 10−7. A column study that was conducted to determine the methane emission from the cover soil showed a 65.8% reduction in the methane emission compared to that of a column without SSB cover, with a cumulative methane emission of 410 milliliters (mL) at the end of 200 hours (h). On the other hand, the volume of methane emitted after 310 h from the column without cover and with the SSB cover was 1850 mL and 692 mL, respectively. The difference between these two values is found to be 22% of the total methane that the cover would have handled in its lifetime (5267 mL). Thus, there is an increase in the percentage of methane adsorption by soil cover from 15% to 22% when the soil was amended with 25% sugarcane bagasse biochar.

Determination of the elastic modulus of fly ash-based stabilizer applied in the trackbed

This paper describes a unique application of a fly ash-based stabilizer in the trackbed of a railway main line. The key goals of the stabilizer application are to protect the subgrade against the ingress of rain water, to increase the frost resistance and to remediate the natural ground constituted of weathered rock. The stabilizer was designed as a mixture of fly ash, generated as a waste material from coal plants, gypsum, calcium oxide and water. The mixture recipe was developed in a laboratory over several years. In 2005, a trial section of a railway line with subgrade consisting of clay limestone (weathered marlite) was built in the municipality of Smiřice. Since then, periodical measurements including collection of samples for laboratory evaluation of the fly ash-based stabilizer have taken place. Over the time span of the measurements, changes in mineral composition and development of fly ash transforming structures leading to the formation of C-A-S-H gel were detected. This paper describes the experimental laboratory investigation of the influence of dynamic loading on the elastic modulus of fly ash stabilizer samples and the development of permanent deformation of the samples with increasing number of loading cycles.

Field monitoring of groundwater responses to heavy rainfalls and the early warning of the Kualiangzi landslide in Sichuan Basin, southwestern China

The Kualiangzi landslide was triggered by heavy rainfalls in the “red beds” area of Sichuan Basin in southwestern China. Differing from other bedrock landslides, the movement of the Kualiangzi landslide was controlled by the subvertical cracks and a subhorizontal bedding plane (dip angle < 10°). The ingress of rainwater in the cracks formed a unique groundwater environment in the slope. Field measurement for rainfall, groundwater movement, and slope displacement has been made for the Kualiangzi landslide since 2013. The field monitoring system consists of two rainfall gauges, seven piezometers, five water-level gauges, and two GPS data loggers. The equipments are embedded near a longitudinal section of the landslide, where severe deformation has been observed in the past 3 years. The groundwater responses to four heavy rainfall events were analyzed between June 16 and July 24 in 2013 coincided with the flood season in Sichuan. Results showed that both of the water level and the pore-water pressure increased after each rainfall event with delay in the response time with respect to the precipitation. The maximum time lag reached 35 h occurred in a heavy rainfall event with cumulative precipitation of 127 mm; such lag effect was significantly weakened in the subsequent heavy rainfall events. In each presented rainfall event, longer infiltration period in the bedrock in the upper slope increased the response time of groundwater, compared to that of in the gravels in the lower slope. A translational landslide conceptual model was built for the Kualiangzi landslide, and the time lag was attributed to the gradual formation of the uplift pressure on the slip surface and the softening of soils at the slip surface. Another important observation is the effect on the slope movement which was caused by the water level (H w) in the transverse tension trough developed at the rear edge of the landslide. Significant negative correlation was found for H w and the slope stability factor (F s), in particular for the last two heavy rainfall events, of which the drastic increase of water level caused significant deterioration in the slope stability. The rapid drop (Δ = 22.5 kPa) of pore-water pressure in the deep bedrock within 1 h and the large increase (Δ = 87.3 mm) of surficial displacement were both monitored in the same period. In the end, a four-level early warning system is established through utilizing H w and the displacement rate D r as the warning indicators. When the large deformation occurred in flood season, the habitants at the leading edge of the landslide can be evacuated in time.

Maintenance of Heritage Building: A Case Study from Ipoh, Malaysia

Heritage buildings represent the tangible cultural heritage of a community. However, many of the heritage buildings have being left neglected. Ipoh as a city rich in heritage, has many dilapidated heritage buildings which are experiencing a resurging interest. However, the problems faced by many owners are the lack of technical information of such buildings, leading to premature abandonment and demolition. Therefore, the objectives of this study are to determine the types and extent of defects present in the building studied. To achieve these objectives, a case study of a century old heritage property in Ipoh, Perak was conducted. The study aims to provide reference to owners and those responsible for the conservation of heritage buildings with similar conditions to identify and prioritize critical defects in relation to the building life span to determine its condition. The findings determined the probable causes of defects such as settlement and façade cracks, which are over 30 years old, were attributed to leaking plumbing pipes, rainwater ingress and the construction of an adjacent 20 story apartment building. The major issues to address were stabilizing the foundation through cement grouting, reinforcing the existing structural systems and roof systems as well as arresting the decay of timber floor structure. In conclusion, major maintenance guidelines are need to address structural issues and weather tightness of the building envelope, especially its roof and drainage systems.

Effects of Outdoor Exposure Angle on the Deterioration of Wood-Based Board Properties

Abstract Wood-based boards were exposed to an outdoor environment at angles of 90° and 45° to the ground surface in order to investigate the effect of exposure angle on board properties. In a study on 5-year outdoor exposure, the effects of the exposure angle varied depending on the type of board. Particleboard (PB) and oriented strand board (OSB) deteriorated faster when exposed at 45° compared with 90°, and the difference was more apparent with longer exposure. Five years of exposure at 45° lowered the retention of the modulus of rupture and internal bond of phenolic resin–bonded PB to 15 and 4 percent, respectively. In contrast, medium-density fiberboard (MDF) showed no difference in deterioration between both exposure angles. After 5 years of exposure, the retention of the modulus of rupture was 70 to 80 percent in MDF, while that of internal bond was 81 to 97 percent, thereby showing that the internal bond was better retained than the modulus of rupture. The high durability of MDF was attributable partly to its smoother surface compared with the other boards, which prevented residual rainwater on the surface from infiltrating into the board. Conversely, PB and OSB were prone to surface weathering, which led to the ingress of rainwater. The resultant swelling resulted in the collapse of bonding points, followed by the formation of voids inside the boards. Residual moisture in the voids then caused decay as well as a further reduction in strength (biodegradation).

Tracking the two-phase flow through a vehicle cowl box

The penetration of rainwater through the heating, ventilation and air conditioning (HVAC) system of a vehicle directly affects the provision of thermal comfort within the vehicle passenger compartment. Present vehicle designs restrict considerably the air management processes owing to reduced space and tighter packaging. In this study, a cowl box, the first element of the vehicle HVAC system, is examined through the scrutiny of the flow field prevailing within it. Particular attention is paid to the effects of cowl flooding on water ingress. The work described is both experimental and computational. An optical anemometer is used to acquire the experimental data within a transparent model of a cowl box. The results are then used to validate and tune the computational fluid dynamics (CFD) calculations performed on the same cowl geometry as well as to perform parametric studies of the features that affect the rainwater penetration. The phenomenon of rainwater ingress has integrated factors with the overall vehicle geometry, body seals at the cowl space, wipers set-up, HVAC blower set-up, rain intensity and road conditions. Therefore, in addition to the model- scale experiments, a full-scale vehicle is examined in the Flow Diagnostics Laboratory (FDL) climatic wind tunnel. The results obtained, using non-intrusive instrumentation, are also used to verify the computational model.

Simulation of road vehicle natural environment in a climatic wind tunnel

This paper describes the development of natural climatic conditions in a closed loop full-scale automotive wind tunnel. The tunnel simulates wind, different rainfalls, a range of air temperature as well as several road conditions. It generates, under controlled heat loading, wind speeds of up to 50 km h with different approach boundary conditions, rainfalls from drizzle to cloudburst, controlled air temperature over the range of 30–20°C below zero and road inclines up to 15° in any direction. The design and optimization process of the tunnel functions is outlined and examples of its use in vehicle development are given. The need to comply with the standardised recommended practice requirements and a compact design are important features of the tunnel. The tunnel provides an important test bed for close scrutiny of the relationship between rainwater ingress, vehicle speed, road condition, heat loading and vehicle geometry. The tunnel can also be used to study vehicle thermal management, vehicle thermal comfort, engine cold starting, and wipers efficiency in severe cold weather. Computational fluid dynamic (CFD) simulation is used to optimize and assess the performance of a number of key tunnel components. To validate the CFD developed model, the resulting flow field around a bluff body placed on the tunnel is closely scrutinized and verified against well-established and published data. Moreover, the numerical prediction is experimentally validated using laser sheet visualisation (LSV). The resulting tunnel is approximately 9.5 m long, 9.5 m high and 3 m wide.

Effects of vehicle HVAC cowl box geometry on rainwater ingress

The penetration of rainwater through the heating ventilation and air conditioning system (HVAC) of a vehicle directly affects the provision of thermal comfort within the vehicle passenger compartment. Present vehicle designs restrict considerably the air-management processes due to reduced space and tighter packaging. In this study, a cowl box, the first element of the vehicle HVAC system, is examined through the scrutiny of the flow field prevailing within it. Particular attention is paid to the effects of reducing the cowl cross-sectional area on water ingress. The work described is both experimental and computational. An optical anemometer is used to acquire the experimental data within a transparent model of a cowl box. The results are then used to validate and tune the Computational Fluid Dynamics (CFD) calculations performed on the same cowl geometry as well as perform parametric studies of the features that affect the rainwater penetration. The phenomenon of rainwater ingress has integrated factors with the overall vehicle geometry and body seals at the cowl space, wipers set-up, HVAC blower setup, rain intensity and road conditions. Therefore, in addition to the model scale experiments, a full-scale vehicle is examined in the Flow Diagnostics Laboratory (FDL) Climatic Wind Tunnel. The results obtained, using nonintrusive instrumentation, are also used to verify the computational model.