b'TECHNOLOGY Climatic Load Stormwater HydrographStormwater/Discharge Eau plusiale/coulementCharheDetention/Retentionclimatique Dtention/RtentionHydrogrammeSystemResistance HydrographSystmeHydrogramme de rsistanceTime / TempsFIGURE 2 FIGURE 2 Hydrographs for a stormwater detention assessmentHydrogramme pour une valuation de la rtention des eaux pluvialesdictates the proportion of rainfall that is detained and the timepic dvacuation observ dans lhydrogramme de charge between storms determines the discharge rates. Accordingly, aclimatique se nomme capacit de rtention. Laugmentation hydrograph curve is required to assess the stormwater detentiondu temps jusquau sommet est appele le dcalage, soit capacity (Figure 2).le temps quil faut pour que leau soit vacue. La partie The stormwater is shown as a climatic load hydrograph. Theombrage entre la charge climatique et les hydrogrammes system hydrograph shows the discharge rate. The reductionmontre le volume retenu. in the peak discharge seen in the climatic load hydrographAu moment de la conception de la SNTC, le volume is referred to as retention or detention capacity. The increaseretenuestncessairepourobtenirleffetdertention in the time to peak is referred to as the lag, the time thatdsir. Le volume maximal retenu se produit lorsque les thewaterwillbedischarged/released.Theshadedareadeux hydrogrammes se rejoignent. Dans le cas des couver-between the climatic load and system hydrographs shows theturesvgtalises(SCV),lartentionmaximaledpend detained volume.de la composition du sol (taux organique vs inorganique) WhendesigningNBSCR,thedetainedvolumeiset du niveau de saturation avant laverse, alors que pour le required to achieve a desired detention effect. The maximumSREP la rtention maximale dpend du volume du plateau detained volume occurs when the two hydrographs intersect.seulement.Lobjectifestdamlioreretdaccrotrela For VRA applications, the maximum detention depends onrtention de leau et des eaux pluviales afin dattnuer les the soil composition (organic vs. inorganic rate) and the levelinondations urbaines.of saturation before the rain event, whereas for the SDA the maximum detention depends on the volume of the tray only.Quels sont les avantages des technologies SNTC ?The objective is to enhance and increase the water detentionLes technologies de SNTC ont le potentiel doffrir de and stormwater capture to mitigate urban flooding. nombreux avantages lisla gestion des eaux pluviales : I)Rduireledbitdepointedestemptes,att- What are the benefits of NBSCR technologies?nuer le risque dinondation, et rduire les dbords The NBSCR technologies have the potential to providepossiblesdesgoutsetlrosiondanslescours multiple benefits related to stormwater management:deau rcepteurs ; I)II)Rutiliserleseauxpluviales(danslestoilettes, Reducing the peak flow from storm events, mitigating flood risk, and reducing the possible sewer overflowslirrigation des gazons et les jardins) ou les laisser and erosion in receiving streams.svaporer dun toit (ce qui rduit les effets dlot de II)Reusingstormwater(e.g.,flushingtoilets,irrigatingchaleur urbain). Par consquent, le rseau municipallawns and gardens) or allowing it to evaporate from areoit moins deau que nen recevrait un systme de rooftop (lessening the effects of urban heat island). Astoit traditionnel. Cela peut prolonger la dure de vie a result, less water reaches the municipal system thandes infrastructures et maintenir lquilibre du cycle would from a traditional roof system. This can extendde leau ;26 ROOFING CANADA FALL/WINTER 2022'