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CUAHSI cyberseminars on Urban Streams

Green infrastructure, groundwater and the sustainable city
Larry Band, Institute for the Environment at University of North Carolina

Watershed context and the evolution of urban streams
Derek Booth, Bren School of Environmental Management at UC Santa Barbara

The Little Stringybark Creek project
Tim Fletcher, University of Melbourne

Contaminants of emerging concern as agents of ecological change in urban streams
Emma Rosi-Marshall, Cary Institute of Ecosystem Studies and Baltimore Ecosystem Study

Stormwater-Stream Connectivity: Process, Context, and Tradeoffs
Anne Jefferson, Kent State University

Stormwater-Stream Connectivity: Process, Context, and Tradeoffs

In a few minutes, I’ll be giving a cyberseminar in CUAHSI’s fantastic sustainable urban streams seminar series. You can join the seminar live at 3:30 pm, or watch a recording of it later. Either way, https://www.cuahsi.org/Posts/Entry/13551 is where you want to go to watch and listen. If you want to know what you’re in for, I’ve attached my late-breaking abstract below. The whole series has been really superb, with great speakers making key points about the state-of-the-science in urban streams and watersheds. I’m honored to be part of the lineup, and I encourage you to check out all of the recordings. Enjoy!

Stormwater-Stream Connectivity: Process, Context, and Tradeoffs

Anne Jefferson

Streams in urban areas are often said to suffer from “urban stream syndrome” resulting in degraded geomorphology, biogeochemistry, and ecosystem function. Uncontrolled or poorly controlled stormwater is a root cause of many of the symptoms of urban stream syndrome, so understanding how stormwater management options affect in-stream processes is important for creating sustainable urban streams. Today’s approaches to stormwater control include green infrastructure distributed throughout the watershed and more centralized stormwater control ponds and wetlands located near the stream. How well do these approaches minimize risks to human health and infrastructure and protect aquatic ecosystems? In this talk, I’ll suggest that the answer depends on three factors: context; process; and tradeoffs. In terms of context, watersheds and stormwater management efforts are situated within a particular natural landscape (climate, soils, etc.); relative to urban development (age and style of development, type of infrastructure); and within the social context of environmental attitudes and economic constraints and incentives. Processes upslope of stormwater controls that affect water quantity and quality and processes within the controls themselves, such as mixing, infiltration and residence time, exert significant influence on how urban stream hydrology, water quality, and ecology responds to stormwater inputs. Where stormwater ponds and wetlands (SCMs) are large inputs to a stream, they can impart distinct water quality signals, and such SCMs are unlikely to restore pre-development stream water quantity and quality. Distributed green infrastructure shows promising reductions in peakflows and total stormwater volumes at the street-scale, but challenges remain in scaling up to enough projects to make a difference at the watershed scale and in ensuring that variability in construction and maintenance don’t reduce the effectiveness of the green infrastructure. Finally, there are tradeoffs in our choices around stormwater management infrastructure, in terms of the broader environmental benefits it can provide versus a more narrow focus on water quantity and quality. Using an ecosystem services framework, I show one approach to examining these tradeoffs. None of the current approaches to managing stormwater are a panacea, but with process-based, contextual studies that also examine limitations and tradeoffs, we can move the science and practice of stormwater management toward better outcomes and more sustainable urban streams.

Development of hyporheic exchange and nutrient uptake following stream restoration

Next week, the Watershed Hydrology Lab will be well represented at the CUAHSI 2014 Biennial Colloquium. We’ll be presenting four posters, so here come the abstracts…

Development of hyporheic exchange and nutrient uptake following stream restoration

Stuart Baker and Anne Jefferson

Stream restoration is a multi-million dollar industry in Ohio, with major goals of improving water quality and degraded habitat. Yet restoration often falls short of significant improvements in water quality and biodiversity. It is thus important to improve the theory and practice of stream restoration in order to achieve greater benefits per dollar spent, yet there are limited data and understanding of the physical and biogeochemical responses to restoration that constrain the potential for water quality and ecological improvements. Hyporheic exchange, the flow of water into and out of the streambed, is an important stream process that serves critical roles in naturally functioning streams, allowing for stream water to participate with the substrate in various processes. Hyporheic flowpaths can be altered by the transport of fine sediment through the stream bed and are thus susceptible to changes in sediment regime and hydraulics, as well as the changes wrought by construction of a restoration project. The goal of this research is to determine the effectiveness of restoration in enhancing hyporheic flow and associated biogeochemical processes to improve water quality. Preliminary results from Kelsey Creek, OH, a second-order stream restored in August 2013, show a decrease in average hydraulic conductivity but an increase in heterogeneity from pre-restoration (geometric mean 8.47×10-5 m/s, range 1.18×10-6-1.19×10-3) to post-restoration (geometric mean 4.41×10-5 m/s, range 2.67×10-5-3.05×10-4) in piezometer nests through large constructed riffle structures. These piezometers also indicate dominance of downwelling throughout riffle structures with only isolated locations of upwelling. Transient storage and hyporheic exchange will be measured with resazurin injections for comparison between pre-restoration and post-restoration, and nutrient injections of NH4Cl at time points following the restoration will compare the nitrogen uptake rates of the restored reach to an unrestored reach downstream. Additional sites are planned for study to include restoration projects of different ages to examine the development of hyporheic exchange and biogeochemistry after completion of restoration projects.

Stormwater control measures modify event-based stream temperature dynamics in urbanized headwaters

Next week, the Watershed Hydrology Lab will be well represented at the CUAHSI 2014 Biennial Colloquium. We’ll be presenting four posters, so here come the abstracts…

Stormwater control measures modify event-based stream temperature dynamics in urbanized headwaters

Grace Garner1, Anne Jefferson2*, Sara McMillan3, Colin Bell4 and David M. Hannah1
1School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
2Department of Geology, Kent State University, Kent, OH, 44240, USA
3Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
4Department of Infrastructure and Environmental System, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA

Urbanization is a widespread and growing cause of hydrological changes and ecological impairment in headwater streams. Stream temperature is an important control on physical, chemical and ecological processes, and is an often neglected water quality variable, such that the effects of urban land use and stormwater management on stream temperature are poorly constrained. Our work aims to identify the influence of stormwater control measures (SCMs) of differing design and location within the watershed on the event-based temperature response of urban streams to precipitation in the North Carolina Piedmont, in order to improve prediction and management of urban impacts. Stream temperature was measured within SCMs, and upstream and downstream of them in two streams between June and September 2012 and 2013. Approximately 60 precipitation events occurred during that period. To unambiguously identify temperature increases resulting from precipitation, surges were identified as a rise in water temperature of ?0.2°C between the hours of 15:30 and 5:30, when the diurnal temperature cycle is either decreasing or static on days without precipitation. Surges up to 5°C were identified in response to precipitation events, with surges occurring both upstream and downstream of the SCM under some conditions. Surges were also recorded within the SCMs, confirming that temperature surges are the result of heated urban runoff. Classification tree modeling was used to evaluate the influence of hydrometeorological drivers on the generation and magnitude of temperature surges. In both streams, event precipitation, antecedent precipitation, and air temperature range were identified as the drivers of whether or not a surge was observed and how large the surge was, though the order and thresholds of these variables differed between the two sites. In a stream with an off-line, pond SCM, the presence of the pond in the lower 10% of the watershed did not affect the magnitude of temperature surges within the stream, but the pond itself had a wider range of surge magnitudes than did the stream. In a watershed with a large in-line pond, and a downstream contributing wetland SCM receiving flow from 40% of the watershed, the wetland increased both the frequency and magnitude of temperature surges observed in the stream. Our results suggest dynamic hydrometeorological conditions, SCM design, and position within a watershed all influence whether stormwater management reduces or enhances temperature surges observed within urban headwater streams, and that these factors should be considered in the recommendations for urban stormwater management systems.

Assessing impacts of green infrastructure at the watershed scale for suburban streets in Parma, Ohio

Next week, the Watershed Hydrology Lab will be well represented at the CUAHSI 2014 Biennial Colloquium. We’ll be presenting four posters, so here come the abstracts…

Assessing impacts of green infrastructure at the watershed scale for suburban streets in Parma, Ohio

Kimberly Jarden, Anne Jefferson, Jennifer Grieser, and Derek Schaefer

High levels of impervious surfaces in urban environments can lead to greater levels of runoff from storm events and overwhelm storm sewer systems. Disconnecting impervious surfaces from storm water systems and redirecting the flow to decentralized green infrastructure treatments can help lessen the detrimental effects on watersheds. The West Creek Watershed is a 36 km2 subwatershed of the Cuyahoga River that contains ~35% impervious surface. We seek to evaluate the hydrologic impacts and pollution reduction of street scale investments using green infrastructure best management practices (BMPs), such as rain gardens, bioretention, and rain barrels. Before-after-control-impact design will pair two streets with 0.001-0.002 ha. lots and two streets with 0.005-0.0075 ha. lots. Flow meters have been installed to measure total discharge, velocity, and stage pre– and post-construction. Runoff data has been preliminarily analyzed to determine if peak discharge for large (> 10 mm) and small (<10 mm) storm events has been reduced after installation of BMPs on the street with 0.001-0.002 ha. lots. Initial results show that the peak flows have not been reduced for most storm events on the street with the green infrastructure. However, several larger events show that peak flows have been reduced on the treatment street and need to be further investigated to ensure no outside hydrological impacts are having an effect on the flow. Initial analysis of total flow volume for each event, pre- and post-construction, show that total volume has increased on the street with green infrastructure treatments. Possible explanation for the increase on flow volume could be attributed to under drains from bioretention creating a more connected flow path to the storm drain or an upstream leak in the control street storm drain. Each scenario will be investigated further to confirm results. Further research will include analysis of the total effect of street-scale BMPs on storm hydrograph characteristics including, hydrograph regression behavior and lag time. Analysis on the accumulation of metals in the bioswales and the reduction of metals in street runoff will also be conducted to determine if the BMP treatments are capturing pollutants associated with storm water. After studying the effect of each individual treatment, we will define the level of disconnected impervious surfaces needed in order to achieve a natural hydrologic regime in this watershed.

Meeting report in this week’s Eos

coverIf you missed the “Laser Specs for Field Hydrology and Biogeochemistry: A USGS-CUAHSI Virtual Workshop” we ran from 27 January to 28 February 2014 and you want to read our take on it in ~500 words, check it out in this week’s Eos (the newsletter of the American Geophysical Union). Co-conveners Richard Keim, Carol Kendall, and I are offer up the lessons learned from the cyber-series. Here’s a teaser:

Laser spectroscopy for analysis of stable isotopes is a rapidly emerging technology with the potential to enable new scientific investigations in hydrology and biogeochemistry. The two basic advantages of laser spectroscopy over mass spectrometry—lower instrument cost and ease of use—mean more laboratories can obtain the capability. Portability of instruments allows field deployment with online analysis of large numbers of samples outside the laboratory. However, the novelty of laser spectroscopy for isotope applications means there is little collective experience, so its strengths and limitations are not as well understood as those of mass spectrometry.

Also be on the lookout for a special USGS publication later this year that contains abstracts from the series.

Save the Date: CUAHSI Biennial Meeting, July 28-30, 2014

logoThe Consortium for the Advancement of Hydrologic Science, Inc. (CUAHSI) is a go-to group for hydrology workshops, conferences, and networking. Their once-every-two-years meeting is a great chance to hear some fantastic talks, meet other researchers and students, and share your work. This year’s meeting is in Sheperdstown, WV (a mere 4.5 hours from Kent) on July 28-30th, and the theme is “Water Across the Critical Zone: From Local to Global Hydrology.” I’m hoping my schedule allows me to be there, and I’m encouraging my students to go too. Hope to see you there!

CUAHSI Cyberseminar on Watershed Sensitivity to Climate and Land Use Change

From an email to CUAHSI members today:

A quick reminder that we invite you to join us for a special CUAHSI Cyberseminar this Thursday at a special time hosted by Roy Haggerty,  Tom Meixner, and Patrick Belmont, members of the Water, Sustainability and Climate  (WSC) community.

Thursday, January 23rd, 2 -3 PM ET

Dr. Thomas Johnson

EPA Office of Research and Development

Watershed Modeling to Assess  the Sensitivity of Streamflow, Nutrient, and Sediment Loads to  Potential Climate Change and Urban Development in 20 U.S. Watersheds

Join the seminar at: http://cuahsi.adobeconnect.com/cyberseminar/

Dr. Johnson will discuss the release of the final report released by EPA this fall. From the release:

“There is growing concern about the potential effects of climate change on water resources. To develop this report, watershed modeling was conducted in 20 large U.S. watersheds to characterize the sensitivity of streamflow, nutrient (nitrogen and phosphorus), and sediment loading to a range of plausible mid-21st century climate change and urban development scenarios. The report also provides an improved understanding of methodological challenges associated with integrating existing tools (e.g., climate models, downscaling approaches, and watershed models) and data sets to address these scientific questions. To view the study and related links, visit: http://cfpub.epa.gov/ncea/global/recordisplay.cfm?deid=256912.”

Please join us on January 23rd. Dr. Johnson will present on the results of the report, and there will be a Q&A following the presentation.

Our regular Cyberseminar series will have a spring theme of “Snow Hydrology,” and is being hosted/organized by Dr. Jessica Lundquist (Washington). The spring series begins February 7th. See http://www.cuahsi.org/Cyberseminars.aspx for more info.

Virtual workshop on laser isotope technology applications in hydrology

CUAHSI is the consortium of universities for the advancement of hydrologic science, inc. and Kent State University became a full member of the consortium in December 2013. That’s good timing, because for the last year I’ve been sitting on the organizing committee for a virtual workshop sponsored by CUAHSI and USGS, and I’m super excited to announce that it’s finally happening and starting soon.

This workshop focuses on field hydrology and biogeochemistry applications of laser-based isotope technology. This may sound like an esoteric topic, but this technology is rapidly expanding the affordability and availability of stable isotope analyses. When I was in graduate school, the only way to get water isotope data was off an expensive and hard to use isotope ratio mass spectrometer. I traveled 10 hours to access one and I swore I’d never have one in my lab. Now, I walk upstairs to use the slightly less expensive and somewhat easier to use laser spec purring along in my lab. Viva technology!

Over the course of 5 weeks, we’ll have presentations from the manufacturers of the two main laser specs (Picarro and Los Gatos Research), commentary on the technology from experts at the USGS and IAEA, examples of applications from experienced users, and a poster session where we can share our data and experiences. The workshop will occur entirely on the web (thanks, sequester) and you can participate in real time or watch recordings of the talks.

The flyer below gives a lot of the information, but you can out even more at the CUAHSI webpage for the workshop.

LaserSpec_Instrumentation_Flyer_01.07.2014

I’m looking forward to learning a ton of information during the workshop, sharing some hot-off-the-instrument data that my undergraduate student and I have been collecting, and hopefully sharing the neat ways we’re integrating the technology into our undergraduate geosciences curriculum at KSU. I hope to see you (virtually) there!