Changes

* “If [[winter]] precipitation falls as rain instead of snow, which may actually occur more frequently in temperate regions with climate change, [[phosphorus]] concentrations in winter have the potential to be equivalent to those observed in other seasons due to the ubiquitous impacts of runoff events.” “Another potential impact of climate change on summer nutrient conditions that has been discussed in the literature is an increase of summer soluble reactive phosphorus (SRP) concentrations in creeks during low flow conditions due to temperature-dependent release from riverine sediments.”<Ref>Long, Daniel L., and Randel L. Dymond. 2014. “Thermal Pollution Mitigation in Cold Water Stream Watersheds Using Bioretention.” Journal of the American Water Resources Association 50 (4):977–87. https://doi.org/10.1111/jawr.12152.</ref>

* “If [[winter]] precipitation falls as rain instead of snow, which may actually occur more frequently in temperate regions with climate change, [[phosphorus]] concentrations in winter have the potential to be equivalent to those observed in other seasons due to the ubiquitous impacts of runoff events.” “Another potential impact of climate change on summer nutrient conditions that has been discussed in the literature is an increase of summer soluble reactive phosphorus (SRP) concentrations in creeks during low flow conditions due to temperature-dependent release from riverine sediments.”<Ref>Long, Daniel L., and Randel L. Dymond. 2014. “Thermal Pollution Mitigation in Cold Water Stream Watersheds Using Bioretention.” Journal of the American Water Resources Association 50 (4):977–87. https://doi.org/10.1111/jawr.12152.</ref>

* “Dominguez et al. (2012) found increases in the intensity of 20- and 50-year return period winter precipitation events over the western United States, while over Canada, Mailhot et al. (2012) showed that the intensity of annual maxima precipitation would increase, with the largest increases for Ontario, the Prairies and Southern Quebec.”<ref>Guinard, Karine, Alain Mailhot, and Daniel Caya. 2015. “Projected Changes in Characteristics of Precipitation Spatial Structures over North America.” International Journal of Climatology 35 (4):596–612. https://doi.org/10.1002/joc.4006.</ref>

* “Dominguez et al. (2012) found increases in the intensity of 20- and 50-year return period winter precipitation events over the western United States, while over Canada, Mailhot et al. (2012) showed that the intensity of annual maxima precipitation would increase, with the largest increases for Ontario, the Prairies and Southern Quebec.”<ref>Guinard, Karine, Alain Mailhot, and Daniel Caya. 2015. “Projected Changes in Characteristics of Precipitation Spatial Structures over North America.” International Journal of Climatology 35 (4):596–612. https://doi.org/10.1002/joc.4006.</ref>

* “The hydrological response to climate change was investigated through stormwater runoff volume and peak flow, while the water quality responses were investigated through the event mean value (EMV) of five parameters: turbidity, conductivity, water temperature, dissolved oxygen (DO) and pH. First flush (FF) effects were also noted. Under future climate scenarios, the EMVs of turbidity increased in all storms except for three events of short duration. The EMVs of conductivity were found to decline in small and frequent storms (return period <5 years); but conductivity EMVs were observed to increase in intensive events (return period ½5 years). In general, an increasing EMV was observed for water temperature, whereas a decreasing trend was found for DO EMV. No clear trend was found in the EMV of pH. In addition, projected future climate scenarios do not produce a stronger FF effect on dissolved solids and suspended solids compared to that produced by the current climate scenario.”<ref>He, Jianxun, Caterina Valeo, Angus Chu, and Norman F. Neumann. 2011. “Stormwater Quantity and Quality Response to Climate Change Using Artificial Neural Networks.” Hydrological Processes 25 (8):1298–1312. https://doi.org/10.1002/hyp.7904.</ref>

* “The hydrological response to climate change was investigated through stormwater runoff volume and peak flow, while the water quality responses were investigated through the event mean value (EMV) of five parameters: turbidity, conductivity, water temperature, dissolved oxygen (DO) and pH. First flush (FF) effects were also noted. Under future climate scenarios, the EMVs of turbidity increased in all storms except for three events of short duration. The EMVs of conductivity were found to decline in small and frequent storms (return period < 5 years); but conductivity EMVs were observed to increase in intensive events (return period ½5 years). In general, an increasing EMV was observed for water temperature, whereas a decreasing trend was found for DO EMV. No clear trend was found in the EMV of pH. In addition, projected future climate scenarios do not produce a stronger FF effect on dissolved solids and suspended solids compared to that produced by the current climate scenario.”<ref>He, Jianxun, Caterina Valeo, Angus Chu, and Norman F. Neumann. 2011. “Stormwater Quantity and Quality Response to Climate Change Using Artificial Neural Networks.” Hydrological Processes 25 (8):1298–1312. https://doi.org/10.1002/hyp.7904.</ref>

* “The potential consequences of climate change for P cycling in streams include (i) increasing prevalence of droughts and extreme summer low flows causing a reduction in baseflow dilution capacity, increased P retention during summer as residence times increase and a greater frequency of anoxia (Caruso, 2002; Van Vliet and Zwolsman, 2008), (ii) changes in magnitude and frequency of extreme high flows and floods causing reduced river P retention capacity and net in-channel loss of P under eutrophic conditions, greater seasonal variability in runoff volumes, carbon and nutrient inputs from terrestrial sources (e.g. more winter runoff and less summer runoff), scouring of streams and more frequent flushing of storm sewer overflows (Newson and Lewin, 1991; Schindler, 1997; Biggs et al., 2000; Bouraoui et al., 2002; Wilby et al., 2006a), (iii) greater range and higher average air tempera- tures causing warming of water temperatures in shallow streams, increasing the time window of biological activity, higher rates of primary production, increased soil wetting/ drying cycles, greater rates of OM mineralization and greater dissolved organic carbon (DOC) concentrations reaching the stream with impacts on microbial populations and metabolic rates (Wilby et al., 2006b; Durance and Ormerod, 2007; Harrison et al., 2008).”  Withers and Jarvie 2008 – study on phosphorus in rivers, this quote shows how climate change would also negatively impact the phosphorus cycle

* “The potential consequences of climate change for phosphorus cycling in streams include (i) increasing prevalence of droughts and extreme summer low flows causing a reduction in baseflow dilution capacity, increased P retention during summer as residence times increase and a greater frequency of anoxia (Caruso, 2002; Van Vliet and Zwolsman, 2008), (ii) changes in magnitude and frequency of extreme high flows and floods causing reduced river P retention capacity and net in-channel loss of phosphorus under eutrophic conditions, greater seasonal variability in runoff volumes, carbon and nutrient inputs from terrestrial sources (e.g. more winter runoff and less summer runoff), scouring of streams and more frequent flushing of storm sewer overflows (Newson and Lewin, 1991; Schindler, 1997; Biggs et al., 2000; Bouraoui et al., 2002; Wilby et al., 2006a), (iii) greater range and higher average air tempera- tures causing warming of water temperatures in shallow streams, increasing the time window of biological activity, higher rates of primary production, increased soil wetting/ drying cycles, greater rates of OM mineralization and greater dissolved organic carbon (DOC) concentrations reaching the stream with impacts on microbial populations and metabolic rates (Wilby et al., 2006b; Durance and Ormerod, 2007; Harrison et al., 2008).”  Withers and Jarvie 2008 – study on phosphorus in rivers, this quote shows how climate change would also negatively impact the phosphorus cycle

* Climate change can substantially increase future urban runoff volume and peak flow rate (Zahmatkesh et al 2016).

* Climate change can substantially increase future urban runoff volume and peak flow rate. "a potential increase of up to 60% in precipitation in the NYC region by 2030". <ref>Zahmatkesh, Zahra, Sj Burian, Mohammad Karamouz, Hassan Tavakol-Davani, and Erfan Goharian. 2015. “Low-Impact Development Practices to Mitigate Climate Change Effects on Urban Stormwater Runoff: Case Study of New York City.” Journal of Irrigation and Drainage Engineering 141 (1):04014043. https://doi.org/10.1061/(ASCE)IR.1943-4774.0000770.</ref>

* Zahmatkesh et al 2015 report a potential increase of up to 60% in precipitation in the NYC region by 2030.  

* Pyke et al 2011 – Boston scenario for with and without LID vs conventional

* Pyke et al 2011 – Boston scenario for with and without LID vs conventional

* “Burian (2006) assesses drainage infrastructure performance in response to increased precipitation intensity. The results show that upstream parts of urban drainage catchments in the United States may be resilient to precipitation effects of climate change because most development codes have required a minimum pipe size that has resulted in oversized drainage systems. Results also show downstream parts of urban catchments are more affected by in- creased precipitation intensity and thus more susceptible to the effects of flooding from climate change.”  cited in Zahmatkesh et al 2014

* “Burian (2006) assesses drainage infrastructure performance in response to increased precipitation intensity. The results show that upstream parts of urban drainage catchments in the United States may be resilient to precipitation effects of climate change because most development codes have required a minimum pipe size that has resulted in oversized drainage systems. Results also show downstream parts of urban catchments are more affected by in- creased precipitation intensity and thus more susceptible to the effects of flooding from climate change.”  cited in Zahmatkesh et al 2014

* “Thus, in order to adapt to the increased winter precipitation expected with climate change, greenspace provision will need to be considered alongside increased storage. There is significant potential to utilize sustainable urban drainage (SUDS) techniques, such as creating [[swales]], [[infiltration]], detention and [[retention ponds]] in parks” <Ref>Gill, S E, J F Handley, a R Ennos, and S Pauleit. 2007. “Adapting Cities for Climate Change: The Role of the Green Infrastructure.” Built Environment 33 (1):115–33. https://doi.org/10.2148/benv.33.1.115.</ref>

* “Thus, in order to adapt to the increased winter precipitation expected with climate change, greenspace provision will need to be considered alongside increased storage. There is significant potential to utilize sustainable urban drainage (SUDS) techniques, such as creating [[swales]], [[infiltration]], detention and [[retention ponds]] in parks” <Ref>Gill, S E, J F Handley, a R Ennos, and S Pauleit. 2007. “Adapting Cities for Climate Change: The Role of the Green Infrastructure.” Built Environment 33 (1):115–33. https://doi.org/10.2148/benv.33.1.115.</ref>

* “CC effects were on average two orders of magnitude greater than LU impacts on mean daily stream T. LU change affected stream T primarily in headwater streams, on average up to 2.1 °C over short durations, and projected CC affected stream T, on average 2.1 - 3.3 °C by 2060.” <ref> Daraio and Bales 2014 – a modelling study that assesses the effects of land use vs climate change on urban stream temperatures </ref>

* “CC effects were on average two orders of magnitude greater than LU impacts on mean daily stream T. LU change affected stream T primarily in headwater streams, on average up to 2.1 °C over short durations, and projected CC affected stream T, on average 2.1 - 3.3 °C by 2060.” <ref> Daraio and Bales 2014 – a modelling study that assesses the effects of land use vs climate change on urban stream temperatures </ref>

*Higher temperatures, greater annual precipitation, larger precipitation events, increase in frequency of high flow events. Future climate scenarios predict a 40 % increase in future TSS loading. Return periods for critical flows are reduced in future scenarios, while larger storms will be more frequent. Baseflow will decrease with potential impacts on rates of stream aggradation. Increased risk of erosion damages to infrastructure . Stream crossings may need to be larger. Erosion thresholds exceeded more frequently. Greater sediment loading in watercourses. Combines with higher peak flows and lower baseflow, altered sediment transport regimes could change the way our rivers form and adjust. Potential change in vegetation, habitat with increase of invasive species, drying wetlands, stress on fish species in warm and turbid waters.<ref>Karen Hofbauer 2016 NCD 2016 Conference Presentation.</ref>  

*Higher temperatures, greater annual precipitation, larger precipitation events, increase in frequency of high flow events. Future climate scenarios predict a 40 % increase in future TSS loading. Return periods for critical flows are reduced in future scenarios, while larger storms will be more frequent. Baseflow will decrease with potential impacts on rates of stream aggradation. Increased risk of erosion damages to infrastructure . Stream crossings may need to be larger. Erosion thresholds exceeded more frequently. Greater sediment loading in watercourses. Combines with higher peak flows and lower baseflow, altered sediment transport regimes could change the way our rivers form and adjust. Potential change in vegetation, habitat with increase of invasive species, drying wetlands, stress on fish species in warm and turbid waters.<ref>Karen Hofbauer 2016 NCD 2016 Conference Presentation.</ref>

===Concerns with projections===

===Concerns with projections===