Trees play a critical role in managing our city’s stormwater runoff. Enjoy this interactive poster from the Arbor Day Foundation highlighting the role trees play in urban stormwater management.
Researchers, led by Estelle Chaussard from the University of Buffalo, link ground water recovery in Santa Clara Valley California to the state’s newly instated water conservation efforts—policies that diverted surface water to refill aquifers
In 2013, interferometric synthetic aperture radar (InSARa) measured a 2-centimeter decrease in ground-level elevation, followed by another 3 centimeters in 2014. The research team estimates a groundwater loss of about a tenth of a cubic kilometer caused the ground to shrink or lower.
Ground surfaces began to expand and rise in September 2015, rising nearly 2 centimeters over the next two years and were at pre-study levels by the end of 2016. This reflects the same time surface water diversion policy went into effect.
Permeable pavement allows water to pass through the surface into the ground generating more groundwater recharge, faster melting of ice and snow, and decreasing the amount of water runoff from a property. Porous concrete, porous asphalt, or interlocking pavers are also good for trees whose roots can access the air and water that flow through the pavers.
Photos: (Top) Demonstration of porous concrete. (Bottom) Water runoff comparison of permeable asphalt and standard concrete.
It’s nearly July and the gardens are green and full of early summer blossoms – using just rainwater.
Late last week the City of Scottsbluff finally turned the water on the downtown gardens, about three months after lawn watering began around the city. Native and well adapted plants use much less water than traditional turf once established. They’re also drought hardy, provide needed habitat for pollinators and create a distinct sense of place with a plant palate tailored for the Nebraska Panhandle.
Drip and emitter systems conserve water by regulating volume, velocity, and direction of water flow. Plants can be targeted with a slow steady specific quantity of water using drip tubes or emitters. This prevents over watering and watering where not needed. And the systems are discreet, designed to function effectively while lying under a layer of mulch.
Nebraska is home of Arbor Day, which we celebrate this Friday. See just how much work trees do!
The following is Part III of a three part series focusing on the City of Scottsbluff’s 319 grant projects. These projects are designed to reduce impervious cover in parking lots, filtering and infiltrating stormwater runoff. This article will go over project successes. For an overview of the projects, see Part I. For project challenges and lessons learned, see Part II.
In the last article, we went over the challenges of landscaping a hot, harsh urban environment. Now that we have gone over the difficulties of these projects, we are going to outline some of the practices we used that worked well. The following is a list of some of the techniques that were effective and that we will be using in the future:
- Plant Selection- Thanks to the help of the Nebraska Forest Service and the Nebraska Statewide Arboretum, we were able to use a very carefully chosen plant list. This plant list included several tried and true plants for our area, such as catmint, yarrow, jupiter’s beard, butterfly milkweed, and asters, as well as some lesser-known selections, such as thelosperma and plumbago. We will be monitoring these landscapes to see which of these plants do well over time, helping to expand our palette of plants we know to be successful in this area.
- Sedges- While this also refers to plant selection, the unique functionality of our sedges merits them their own bullet point. Because the projects are designed to capture stormwater, and because the soils were in such poor condition when we started our projects, we had several areas that were poorly drained. These were the areas where we planted sedges, some of them which were literally planted in standing water. These sedges have thrived, looking very attractive while serving the very important function of cleaning and filtering stormwater before it reaches the storm drain or is infiltrated into the ground. There are very few plants that do well when exposed to extended periods of standing water; we have had great success with using sedges in these difficult areas.
- Beehive Storm Grate- The previous storm drain was a typical rectangle grate that was flush with the ground. We talked about some of the challenges of mulch in our previous article; one of the other challenges is that it can plug a storm drain. The storm drain we chose for the overflow of our retention area, shown below, is designed to keep from plugging when the water gets deeper and mulch starts floating. After experiencing a few strong thunderstorms, it appears that this design has been very effective at keeping the storm drain open to receive overflowing stormwater runoff.
- Strategic Placement of Hardscape- We allowed several areas throughout the landscape for people to pass through as they were leaving their vehicles. This seems to have cut down on the amount of foot traffic we receive in the landscape itself. Additionally, in an area that was constantly being driven over, we strategically placed a boulder. This not only has aesthetic value, it has completely stopped vehicles from driving over this part of the landscape.
At this time, those are the most noticeable successes that we have seen. We are hoping that over time, using large landscape beds with adequate soil rooting volume for trees will help the trees to be more successful long-term; however, it will be several years before we know for sure if it is a success. We are also hoping to turn off the drip irrigation systems in the future. During their first summer, though, we will be leaving the irrigation on to help the plants establish their root systems. We may have to continue irrigating during extended dry periods. We will also be observing our plants over time to see how they do- watch for future articles outlining specific plant selections that have done well. All in all, perhaps the greatest success has been being able to remove over 9,500 square feet of concrete from our parking lots and replace it with a beautiful, functional landscape that will have great environmental benefits for years to come.
The following is Part II of a three part series focusing on the City of Scottsbluff’s 319 grant projects. These projects are designed to reduce impervious cover in parking lots, filtering and infiltrating stormwater runoff. This article will go over challenges and lessons learned from the projects. For an overview of the projects, see Part I.
In our last article, we went over the process of removing concrete and installing landscaping to create green areas throughout our downtown parking lots. There are several factors that, when combined, make it extremely difficult for a landscape to be successful in an urban environment. The following is a list of those challenges, along with a few of the lessons that we have learned so far. Over time, we will be continuing to observe and experiment with these landscapes to determine the best ways to make them successful. Continue reading Greening Up the Urban Environment- Part II