Winter Flooding Research Articles

Vliyanie stoka reki Chernoy v periody pavodka i mezheni na ekologicheskoe sostoyanie kutovoy chasti akvatorii Sevastopol'skoy bukhty

Purpose. Climatic conditions for the winter and spring river floods in Crimea are assessed by the example of the Chernaya River. The scientific literature data permitted to analyze salinity dynamics in the Sevastopol Bay during an intensive flood, which is extremely rare in contrast to the high water cases occurring rather frequently. Methods and Results. Based on the available information and using the analyzed in situ data on the Sevastopol Bay apex and the Chernaya River obtained by the Marine Hydrophysical Institute in 2007–2017, considered are the meteorological conditions for a winter-spring high water. The impact of high water upon the hydrological regime and the ecological state of the Sevastopol Bay apex and the Chernaya River mouth is analyzed. Contribution of a winter-spring high water to pollution of the Sevastopol Bay apex with nutrients is assessed. The ecological state of the bay apex during the peculiar winter-spring high water in February, 2015 is compared to that during the low water in September, 2015. Conclusions. The increased content of inorganic nitrogen during a winter-spring flood should be taken into account while calculating the assimilation capacity of the ecosystem under study and assessing the trophic index. The joint analysis of the expeditionary in situ data and the available information from the scientific literary made it possible to conclude that in course of the last decade, salinity in the Chernaya River mouth gradually increased. This can testify the fact that frequency and intensity of the winter-spring floods tend to go down.

Effect of Rice Winter Cultural Management Practices on the Size of the Hatching Population of Triops longicaudatus (Notostraca: Triopsidae) in California Rice Fields.

The tadpole shrimp [Triops longicaudatus (Leconte)] has emerged as a significant pest of rice grown in California in recent decades. The change in T. longicaudatus' pest status has coincided with changes in cultural management of residual rice straw postharvest. Policy changes have reduced the postharvest burning of fields from nearly 95% to less than 10%, promoting increased use of winter flooding as a means of accelerating straw decomposition. Field and laboratory trials were conducted from 2015 to 2017 at the Rice Experiment Station in Biggs, CA and in greenhouses at the University of California (UC) Davis to evaluate the effects of burning, flooding, and a fallow control on T. longicaudatus population dynamics. Experiments demonstrated that burning of rice straw failed to suppress densities of hatching T. longicaudatus and actually had the reverse effect, causing a 51% increase in numbers hatching, perhaps as a result of burning triggering termination of multiyear T. longicaudatus egg dormancy. Winter flooding had no measurable effect on T. longicaudatus hatch. Thus, these changes in winter cultural practices do not appear to be responsible for the emergence of T. longicaudatus as a major rice pest.

Effects of winter flooding on the soil nitrogen fractions and organic rice growth in a paddy field with low nitrogen fertility

Effects of winter flooding on the soil nitrogen fractions and organic rice growth in a paddy field with low nitrogen fertility

Sediment and nutrient deposition in different riparian forests and floods of the Middle Paraná River

AbstractSedimentation processes are important to the dynamics of lowland fluvial systems and depend on the characteristics of floods and of riparian ecosystems. The few known studies for the Paraná River system analysed only summer floods without considering the context in which the sedimentation occurred. This study focuses on sedimentation in three riparian forests during one summer and two winter floods of the Paraná River, quantifying the amount of deposited sediments, determining their texture, and measuring the associated quantities of Total Phosphorous (TP) and Total Nitrogen (TN). This study takes into account the elevations, floristic attributes, and geomorphologic context of the three forests, as well as water and sediment transport during floods. Differences in the floods' water discharge, wash load, and duration determined differences in the total amounts of drained water and mobilized sediments. The amount of sediments ranged from 0 to 510 kg m‐2 in the different floods and riparian forests studied. The texture was statistically different between the two winter floods, and between some riparian forests. The analysis of nutrients showed that 1 to 4919 kg ha‐1 of TP and 4.2 to 1152 kg ha‐1 of TN were deposited during the three floods in all forest types. Our results show that the amounts from winter floods can be as important as those from summer floods. These results provide insight not only into the importance of winter floods in the deposition processes, but also into the role of both types of floods as natural instruments of fertilization for floodplain–river ecosystems.

Long Periods of Increased/Decreased Runoffs of Large Russian Rivers

Long series of annual and seasonal runoffs of large Russian rivers (the Volga at Volgograd, the Don at Razdorskaya, the Yenisei at Igarka, and the Lena at Kyusyur) since the 1870s for the Russian Plain rivers and since the 1930s for the Siberian rivers have been analyzed. Long periods (phases) of increased and decreased water flow have been identified. The boundaries of contrast phases are determined with cumulative deviation curves in combination with Student’s test. The duration of the phases varies from 20–25 years to many decades (for runoff in low-water seasons of the Volga and Don). For the Volga and Don, the phases of decreased runoff are generally longer than increased flow phases (this is especially true for low-water seasons). The identified contrast phases show a statistically significant difference between the annual and seasonal runoffs, which varies from 10 to 65%. In the phases of increased flow, high-water years occur much more often than low-water years, and vice versa. In the period of current climate warming (since 1981), the changes in annual runoff relative to the calculated runoff of the reference period (from the 1930s to 1980) are opposing, i.e., the runoff decreased in the Don and increased in the Volga, Yenisei, and Lena. In this case, the changes are most significant in the Don. In the period of current climate warming, both the winter and snow-melt flood runoff has increased only for the Lena. At the same time, the contributions of climatic and anthropogenic factors to the changes in runoff differ significantly for each of the rivers under study.

Recent snow cover changes over central European low mountain ranges

AbstractIn this study, we simulated the snow water equivalent (SWE), rain‐on‐snow (ROS) events, evapotranspiration, and run‐off for the period 1961–2016 in a central European region covered by low mountain ranges (<820 m a.s.l.) using a distributed hydrological model TRAnspiration and INterception evaporation model (TRAIN). We utilized improved cloud‐free Moderate Resolution Imaging Spectroradiometer (MODIS) snow cover products to evaluate the modelled snow‐covered area, indicating a good performance of the snow modelling. We analysed the intra‐ and inter‐annual variations of the simulated hydrological variables and the synchronous climate variables (air temperature and precipitation). Trend detection indicates a significant SWE decline throughout the snow season, but principally at the high elevations; the most severe warming occurred in early spring (March), whereas precipitation showed a slight increase in January and February. The snowpack in February has displayed the most striking reduction during the past 56 years, which is likely related to both the highest susceptibility of snow to warming and the increased ROS occurrence in February since the early 1990s. The increased combination of high temperatures and extreme rainfalls, as well as the earlier snowmelt, has resulted in a run‐off increase during the earlier winter but a decrease in March. The expected changing climate towards warmer and wetter winters will probably exacerbate winter flooding in the future.

Monitoring snowpack outflow volumes and their isotopic composition to better understand streamflow generation during rain-on-snow events

Abstract. Rain-on-snow (ROS) events in mountainous catchments can cause enhanced snowmelt, leading to an increased risk of destructive winter floods. However, due to differences in topography and forest cover, the generation of snowpack outflow volumes and their contribution to streamflow are spatially and temporally variable during ROS events. In order to adequately predict such flood events with hydrological models, an enhanced process understanding of the contribution of rainwater and snowmelt to stream water is needed. In this study, we monitored and sampled snowpack outflow with fully automated snowmelt lysimeter systems installed at three different elevations in a pre-Alpine catchment in central Switzerland. We measured snowpack outflow volumes during the winters of 2017 and 2018, as well as snowpack outflow isotopic compositions in winter 2017. Snowpack outflow volumes were highly variable in time and space, reflecting differences in snow accumulation and melt. In winter 2017, around 815 mm of snowpack outflow occurred at our reference site (grassland 1220 m a.s.l. – metres above sea level), whereas snowpack outflow was 16 % less at the nearby forest site (1185 m a.s.l.), and 62 % greater at another grassland site located 200 m higher (1420 m a.s.l.). A detailed analysis of 10 ROS events showed that the differences in snowpack outflow volumes could be explained mainly by rainfall volumes and initial snow depths. The isotope signals of snowpack outflow were more damped than those of incoming rainwater at all three sites, with the most damped signal at the highest elevation site because its snowpack was the thickest and the residence times of liquid water in its snowpack were the longest, thus enhancing isotopic mixing in the snowpack. The contribution of snowpack outflow to streamflow, estimated with an isotope-based two-component end-member mixing model, differed substantially among the three lysimeter sites (i.e. between 7±4 and 91±21 %). Because the vegetation in our study catchment is a mixture of grassland and forest, with elevations ranging from 1000 to 1500 m a.s.l., our site-specific hydrograph separation estimates can only provide a range of snowpack outflow contributions to discharge from different parts of the study area. Thus, the catchment-average contribution of snowpack outflow to stream discharge is likely to lie between the end-member mixing estimates derived from the three site-specific data sets. This information may be useful for improving hydrological models in snow-dominated catchments.

Rice yield and soil fertility of an organic paddy system with winter flooding

ABSTRACT Organic farming is promoted as a way to produce food while minimizing harm to ecosystems. We examined the feasibility of organic farming using applications of common organic materials to produce standard yields of rice (Oryza sativa L.). From 2012 to 2016, we investigated the effects of rice bran, leftover grains, and soybean (Glycine max (L.) Merr.) curd residue in place of inorganic fertilizer and the effects of winter flooding on brown rice yield and on the availability of nitrogen (N) and phosphorus (P) under rice-rice-soybean rotation in Ibaraki Prefecture, Japan. The yield was greatest at 581 g m−2 with winter flooding in 2013 and smallest at 347 g m−2 without winter flooding in 2016. The organic materials applied 7.3–7.5 g N m−2 and 3.2–4.7 g P m−2, which supplied 142% ± 37% of the N and 429% ± 125% of the P present in the ear of rice at harvest in plots without winter flooding. The rates of organic materials applied would maintain soil N and P content. Winter flooding increased the ammonium concentration in the soil solution, straw dry matter at harvest, and available N in the plow layer during winter. Our practice, which improved N supply in later growth stages and P availability, supported an adequate rice yield and a conserved available N.

Effect of different rotation systems on mercury methylation in paddy fields

Rice (Oryza sativa) paddy is the hotspot of mercury (Hg) methylation. Given distinct influences of rotation systems on the physicochemical properties of paddy soils, we hypothesized different rotation systems in rice paddies inducing a large difference in Hg methylation. Here, we investigated Hg species distribution, dissolved organic matter (DOM) features, and Hg methylation in five rotation systems (Other farmland newly reclaim into paddy field, i.e., NR-R; Drain the water in winter, i.e., DW-R; Flooding in winter, i.e., FW-R; Rape-Rice rotation, i.e., Ra-R; Wheat-Rice rotation, i.e., Wh-R) of paddy fields to identify such hypothesis. Results shown that FW-R had the strongest Hg methylation, followed by Ra-R and Wh-R, then DW-R, and finally NR-R. We further found that much higher soil organic matter (SOM) and organo-chelated Hg (Hg-o) from straw residues and root exudates were the main cause for the greater Hg methylation in FW-R, Ra-R and Wh-R. This was because the protein-like fraction of SOM facilitated the net production of methyl Hg (MeHg), meanwhile the humin-like fraction had a strong affinity to MeHg in paddy soils. Therefore, it can be concluded that paddy soil under DW-R was the optimum pattern in order to reduce the occurrence of Hg methylation. However, paddy soils under Ra-R and Wh-R were the recommendable patterns if the productivity of paddy fields was considered.

The Adriatic Coast and Tourist Potentials in the Lagoon Ecosystems

The Adriatic coast is characterized by the presence of a highly diversified lagoon system. That is considered to be a high tourism potential and a basis for a more sustainable development of the economy of the area in which they are found. Changes of sea level rise on the Adriatic coast lagoon prominently displayed on the change of biodiversity. Besides the natural factors in this lagoon as well as all other lagoons of the Adriatic coast it feels a lot during the last 60 years of pressure from human society itself. In the dynamics of the waters of the Patok lagoon play a major role in hydrological processes of climate (the arrival of water through tides, increasing during heavy autumn, winter flooding, evaporation process of the wind, etc.), which raise or lower the level water in the lagoon creating this process through channels connecting the Patoku sea. The study aims to identify the values of this wetland complex located in the coastline and is identified as a region in a critical condition and vulnerable to climate change. Here, it can be successfully develop several types of tourism: the creative and ecological. The chaotic urbanization and the problems that derive from it, have arisen massive violation of environmental balance, associated with environmental, social and demographic problems. The paper, it is based on a multi-year work to show their biodiversity values, as well as the measures needed to be taken in order to build the tourism sector

Climate change and European rivers: An eco‐hydromorphological perspective

AbstractClimate change is expected to modify temperature and precipitation patterns throughout Europe, leading to warmer drier summers; wetter, milder winters; and an extended growing season. Alterations to feedbacks between important eco‐physical structuring processes driven by climate change may modulate river morphology, floodplain characteristics, and their biological communities. Current understanding is reviewed and synthesised to explore the potential responses, mechanisms, and ramifications of climatic shifts for the European riverscape. Fundamental drivers of change are expected to be (a) disturbance deviation beyond the historical norm and (b) vegetation morphodynamics, a key river process where ecological and fluvial‐geomorphological attributes interact to shape the physical environment. Increased seasonal temperature, summer drought, and winter flooding may affect the colonisation, growth, and mortality of plant species with consequences for riverscape structure and function as succession patterns adjust with repercussions for hydraulics and sediment dynamics. Such opposing winter and summer climate regimes are likely to impact vegetation patch dynamics, reflected in an increasingly variable patch mosaic as disturbance intensity deviates further from historical background conditions. How changes to climate drivers manifest themselves in individual river systems will also be affected by attributes such as catchment topography, geology, vegetation type, and previous human alterations. Where large scale change occurs, it will have consequences for the type and function of biological communities inhabiting the riverscape. Conventional engineering responses to meteorological disturbance will amplify the effect on river biota by reducing their ecological resilience, highlighting the need for a management response that integrates ecological and societal benefits simultaneously.

Impact of climate change on European winter and summer flood losses

Climate change is expected to alter European floods and associated economic losses in various ways. Here we investigate the impact of precipitation change on European average winter and summer financial losses due to flooding under a 1.5 °C warming scenario (reflecting a projected climate in the year 2115 according to RCP2.6) and for a counterfactual current-climate scenario where the climate has evolved without anthropogenic influence (reflecting a climate corresponding to pre-industrial conditions). Climate scenarios were generated with the Community Atmospheric Model (CAM) version 5. For each scenario, we derive a set of weights that when applied to the current climate's precipitation results in a climatology that approximates that of the scenario. We apply the weights to annual losses from a well-calibrated (to the current climate) flood loss model that spans 50,000 years and re-compute the average annual loss to assess the impact of precipitation changes induced by anthropogenic climate change. The method relies on a large stochastic set of physically based flood model simulations and allows quick assessment of potential loss changes due to change in precipitation based on two statistics, namely total precipitation, and total precipitation of very wet days (defined here as the total precipitation of days above the 95th percentile of daily precipitation). We compute the statistics with the raw CAM precipitation and bias-corrected precipitation. Our results show that for both raw and bias-corrected statistics i) average flood loss in Europe generally tend to increase in winter and decrease in summer for the future scenario, and consistent with that change we also show that ii) average flood losses have increased (decreased) for winter (summer) from pre-industrial conditions to the current day. The magnitude of the change varies among scenarios and statistics chosen.

Agroecosystem resilience in response to extreme winter flooding

Evidence suggests that climate change is increasing the frequency of extreme weather events (e.g. excessive rainfall, heat, wind). The winter of 2013-14 saw exceptional levels of rainfall across the UK leading to extreme and prolonged flooding (up to 3 months with floodwater depths up to 3 m) in several low-lying agricultural areas (e.g. Somerset Levels, Thames Valley). The impact of extreme flooding and the speed of ecosystem recovery at the field-scale, however, remain poorly understood. The main objectives of this study were therefore to: (1) assess the effect of this extreme winter flooding event on a range of soil physical, chemical and biological quality indicators at 15 flood-affected sites (arable and grassland), (2) determine if these changes in soil health were reversible in the short term (< 1 year), and (3) to evaluate the effectiveness of different mechanical interventions (sward-lifting, subsoiling, slot-seeding and aerating) to accelerate the amelioration of the damage caused by winter flooding at 2 of the 15 sites. Once the floodwater had receded (April 2014), we found that several of the measured soil quality indicators were negatively affected in the flooded areas in comparison with non-flooded areas. This included a decrease in soil bulk density (by 19%), soil pH (by 0.4 units), and available P (by up to 42%). Flooding increased soil microbial biomass (60%), induced a shift in soil microbial community structure and reduced earthworm numbers. After 8 months of recovery, only soil pH remained significantly reduced (by 0.3 units) in the flooded areas in comparison to the unflooded areas. Flooding had a negative impact on the overlying vegetation at the arable sites (biomass production was reduced by between 19 and 34%) but had no major impact at the grassland sites in the long-term. In the flood amelioration experiment, the subsoiled plots produced grass with a higher nutrient content (e.g. N - up to 35%, Ca - up to 19% and Mg - up to 58%). However, the four different interventions appeared to have little positive impact on most of the soil quality indicators measured. In conclusion, extreme winter flooding was found to induce short-term alterations in key soil quality indicators and to destroy winter crops, although these effects did not persist in the longer term. Our results therefore indicate that the temperate agroecosystems evaluated here were highly resilient to winter flood stress and that recovery to a pre-flood state could be achieved within 1 year. Improved management strategies are still needed to speed up the rate of recovery after flood events to facilitate a faster return to agricultural production.

Flooding Influences Waterbird Abundance at Poyang Lake, China

With increases in the severity and frequency of weather extremes, there is growing concern about the ecological effects of these events. However, compared to gradual climate changes, the impacts of weather extremes have been much less studied. An extreme flood struck Poyang Lake, China, a globally important wintering ground for waterbirds, in the winter of 2015-2016. The effects of the flood on waterbird richness and abundance at Poyang Lake was assessed by comparing waterbird survey data at nine sub-lakes before (2014-2015), during (2015-2016) and after (2016-2017 and 2017-2018) the winter flood. Flooding greatly influenced waterbird abundance, with the abundance of all birds and each bird group declining by 19.7-75.5% during the flood winter relative to their values during the previous winter. Total waterbird abundance increased rapidly to pre-flood levels 1 year after the flood, suggesting that flooding mainly influenced waterbird distributions by causing waterbirds to escape to adjacent refugia. The negative impacts of extreme flooding shown here indicate that caution should be exercised in planning for a dam at the outlet of Poyang Lake. The proposed dam might have the potential to create the extreme high water levels that are unsuitable for many waterbirds.

Spatial analysis of urban flooding and extreme heat hazard potential in Portland, OR

Mapping individual and combined hazard potential within a city is key to understanding how urban populations may disproportionately exposed to hazards at different times of the year. Using a Topographic Wetness Index (TWI) and an Urban Heat Index (UHI) to model winter flood and summer heat hazard potential respectively, this research uses a geographic information system (GIS) to develop a combined index, and tests for relationships between sociodemographic variables and environmental hazard potential. Along with data from the American Community Survey, and tax lot information, index values are summarized by census block groups, and tested against sociodemographic and biophysical variables for correlations. An exploratory regression identifies unique combinations of variables that produce the highest degree of explanation across all census block groups. Spatial models, including a spatial error model, spatial lag model and a geographically weighted regression (GWR) model further tests how relationships vary across Portland, and identifies areas that may face acute impacts from flooding and heat. Results show combined sewer pipe density, green space, impervious surface, population density, and percentage of population without higher education explained 69% of the variation of the combined hazard potential. GWR further identified how these variables were non-stationary across space in their relationship with the combined hazard index and explained 80% of the variation of combined hazard potential. Our findings offer practitioners and researchers a dual-hazard perspective for assessing the role of socioeconomic conditions when designing resilient infrastructure.

Modulation of Economic Losses From European Floods by the North Atlantic Oscillation

AbstractThe space‐time structure of flood losses is arguably related to large‐scale climatic patterns; however, this interconnection is not always well understood. Here we show that the North Atlantic Oscillation (NAO) correlates with the occurrence of catastrophic floods across Europe and the associated economic losses. The analysis reveals that in Northern Europe the majority of historic winter floods occurred during a positive NAO state, whereas the majority of summer floods occurred during a negative state. Analogous, but stronger, patterns can be observed in individual Atlantic countries. Through the application of a state‐of‐the‐art catastrophe model, we find that there is a statistically significant relationship between the NAO and flood losses. Critically, we observe that the average flood loss during opposite NAO states can differ by up to 50%. These results can inform financial preparedness and disaster fund allocation, as stakeholders, such as governments and insurance companies, can distribute resources more effectively.

Hydroclimate Variability in Snow-Fed River Systems: Local Water Managers’ Perspectives on Adapting to the New Normal

AbstractBetween water years 2012 and 2017, the Truckee–Carson river system in the western United States experienced both historic-low and record-high Sierra Nevada snowpack, anomalously warm temperatures, and winter and spring flooding. As part of an ongoing collaborative modeling research program in the river system, researchers conduct annual interviews with key local water managers to characterize local climate adaptation strategies and implementation barriers, and identify science information needs to prioritize ongoing research activities. This article presents new findings from a third wave of interviews conducted with the same water managers following the historic 2017 wet year. Comparison of these data suggests that managers increased their adaptation efforts described during previous consecutive drought years (2015 and 2016). In 2017, comparatively fewer managers described climate uncertainty as an implementation barrier, exemplifying recent hydroclimate variability as the “new normal” climate for which they should plan. An assessment of recent conditions reveals that recent water years bound historical observations and are consistent with estimated paleoclimate extremes in terms of magnitude, but not persistence, of both dry and wet conditions. Comparison to projected future climate conditions affirms managers’ perspectives that increased hydroclimate variability, inclusive of drought and flood extremes, defines the new normal climate anticipated for the region. To support long-term adaptation planning, managers requested that researchers prioritize simulations of alternative water management strategies that account for nonstationary climate patterns and quantify implications system-wide. This article illustrates how interdisciplinary research that integrates local knowledge with applied climate science research can support adaptive water management in snow-fed river systems.

Possible causes of the flooding over south China during the 2015/2016 winter

Sequential heavy rainfall clusters and resultant severe winter flooding was observed over South China during the 2015/2016 super El Niño event. In the present, the intra‐seasonal oscillations (ISOs) related with heavy rainfall over East Asia from late autumn to early winter in 2015/2016 were investigated using the daily in situ rainfall records and the NCEP‐DOE Reanalysis data set. Results suggested that the successive heavy winter rainfall events in 2015/2016 were contributed by the ISOs with significant periods of 10–25 and 30–45 days. The wet phase of 10–25‐day ISO was jointly induced by the anomalous convergence of the low‐level water vapour associated with the tropical–subtropical interaction and the upper‐level divergence attributed to the eastwards propagating wavetrain. However in the wet phase of the 30–45‐day ISO, the anomalous upper‐level divergence was possibly caused by the weaker East Asian trough and the stronger barotropic westerly in subtropics. The 30–45‐day ISO can facilitate the eastwards propagation of the 10–25‐day ISO by providing a benefit upper‐level waveguide. Afterwards, the low‐level southwesterly surrounding the Tibetan Plateau gets enhanced to bring more moisture into South China where the winter flooding was serious in 2015/2016. In contrast, the more‐than‐normal winter rainfall was weaker in the super El Niño of 1997/1998 due to the lack of the 30–45‐day ISO. Therefore, the strongest winter rainfall anomaly over SC was ascribed to the superposition between the wet phases of 10–25 and 30–45‐day ISOs in 2015/2016.

Pollution Problem of Kilicozu Creek (Kirsehir)

Kirsehir Kilicozu Creek originates from the northern slope of Baran Mountain and runs to the north first and then makes a wide bow towards the south and passes Cogun, Kirsehir and Guzler and joins Kizilirmak. It length is approximately 80 km and is known as Arasozu up until Cogun. Kizilirmak is intertwined in the area between Cogun and Taka regions and receives Igdelioz and Salgosteren at the west and receives Bas Creek at the east. Kirsehir-Kilicozu Creek is used for irrigation mainly. Cogun Dam was built on the Creek in the second half of 1960s by State Hydraulic Works with intense works. İgdeli, Kilicozu and Guzler irrigation regulators were built on the Creek. The water regime of the Creek is irregular. Its water is reduced during the arid summer months considerably. It floods in winter and spring months after torrential rains. The Creek surged and flooded because of heavy rains and melting snow on January 23-24, 1966 and the agricultural areas in the valley floor remained under water and 41 buildings in Kirsehir were severely damaged. Key Words: Kilicozu Creek, environmental pollution, science education DOI : 10.7176/JSTR/5-2-42

Rehabilitation of Brougham Castle Bridge, UK

Brougham Castle Bridge is a three-span masonry arch highway bridge that has suffered significant scour damage to foundations and substructure with referred damage through the superstructure. This paper presents an engineer’s account of the appraisal, investigation, assessment of structural action and the design and execution of repairs for stabilising the structure. The analytical tool employed to interpret the flow of force was a thrust-line graphical equilibrium analysis. It will be demonstrated that this analytical approach accords with the observed structural pathology, thus giving a clear understanding as to where the loads are going, that they may be effectively grappled with. Through thrust-line analysis, continued stability could be demonstrated despite substantial changes in the foundation conditions. It seems fitting that this efficient, robust and confidence-building tool is the same used by the engineers who originally designed many of these bridges. Using this ‘historical approach’, a successful intervention was executed; initially emergency stabilisation work to save the bridge from collapse and latterly permanent rehabilitation works to bring the bridge back into service in advance of the upcoming winter floods.