User:Mackieg4/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
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
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)