NgoJanuwari ka-2010, iToronto yaba sisixeko sokuqala kuMntla Melika ukufuna ukufakelwa kophahla oluluhlaza kuphuhliso olutsha lwezorhwebo, lweziko, kunye neentsapho ezininzi kwisixeko sonke. Kwiveki ezayo, imfuneko iya kwanda ukuze isebenze kuphuhliso olutsha lwemizi-mveliso ngokunjalo.

Ngamafutshane, ¡°uphahla oluluhlaza¡± luphahla olutyaliweyo. Uphahla oluluhlaza luvelisa izibonelelo ezininzi zokusingqongileyo ngokunciphisa isiphumo sesiqithi sobushushu sasezidolophini kunye nemfuno yamandla ehambelanayo, ukufunxa amanzi emvula ngaphambi kokuba abaleke, kuphuculwe umgangatho womoya, nokuzisa indalo kunye nendalo eyahluka-hlukeneyo kwimekobume yasezidolophini. Kwiimeko ezininzi, uphahla oluluhlaza lunokonwatyiswa luluntu njengokuba ipaki inokuba njalo.

Toronto¡¯s iimfuno ziqulethwe kumthetho kamasipala obandakanya imigangatho xa uphahla eluhlaza kufuneka kwaye zeziphi izinto ezifunekayo kuyilo. Ngokubanzi, izakhiwo ezincinci zokuhlala kunye nezorhwebo (ezifana nezakhiwo zokuhlala ezingaphantsi kwemigangatho emithandathu ubude) zikhululekile; ukusuka apho, ubukhulu besakhiwo, isahlulo sezityalo sophahla kufuneka sibe sikhulu. Kwezona zakhiwo zikhulu, ama-60 ekhulwini eendawo ezifumaneka eluphahleni kufuneka zibe nezityalo.

Kwizakhiwo zoshishino, iimfuno azikho mfuneko. Umthetho kamasipala uya kufuna ukuba i-10 lepesenti yendawo yophahla ekhoyo kwizakhiwo ezitsha zemizi-mveliso igqunywe, ngaphandle kokuba isakhiwo sisebenzisa ¡°izinto zokufulela ezipholileyo¡± kwi-100 lepesenti yendawo yophahla ekhoyo kwaye sinemilinganiselo yokugcinwa kwamanzi esiphango ngokwaneleyo ukubamba i-50 ekhulwini yemvula yonyaka (okanye i-5 mm yokuqala kwimvula nganye) kwisiza. Kuzo zonke izakhiwo, iiyantlukwano zokuthotyelwa (umzekelo, ukugquma indawo yophahla oluncinane kunye nezityalo) zinokucelwa ukuba zikhatshwa yimirhumo (esitshixo kubukhulu besakhiwo) etyalwe kwinkuthazo yophuhliso lophahla oluluhlaza phakathi kwabanini bezakhiwo abakhoyo. Iiyantlukwano kufuneka zinikwe liBhunga leSixeko.

Umbutho woshishino iGreen Roofs for Healthy Cities ubhengeze ukuwa kokugqibela kwingxelo yeendaba ukuba iimfuno zophahla oluluhlaza zaseToronto ¡¯s sele zibangele ngaphezu kwe-1.2 yezigidi zeemitha zesikwere (113,300 square metres) yendawo entsha eluhlaza ecetywayo kuphuhliso lwezorhwebo, lweziko, kunye neentsapho ezininzi kwisixeko. Ngokutsho kombutho, izibonelelo ziya kubandakanya imisebenzi engaphezulu kwe-125 yexesha elizeleyo ehambelana nokuveliswa, ukuyila, ukufakwa kunye nokugcinwa kwamaphahla; ukuncitshiswa kwamanzi angaphezu kwama-435 000 eekyubhiki mitha zamanzi emvula (anele ukuzalisa amadama okuqubha amalunga nama-50 alingana neOlimpiki) nyaka ngamnye; kunye nokonga amandla ngonyaka ngaphezulu kwe-1.5 yezigidi ze-KWH kubanini bezakhiwo. Okukhona inkqubo isebenza ixesha elide, kokukhona izibonelelo ziya kwanda.

Umfanekiso we-triptych ongentla waphuhliswa ngabafundi beDyunivesithi yaseToronto ukubonisa utshintsho olunokuthi lwenzeke kwiminyaka elishumi yenkqubela phambili phantsi kweemfuno zesixeko¡¯s. Ngaphambi kwalo mthetho kamasipala, iToronto yayiyeyesibini phakathi kwezixeko zaseMntla Melika (emva kweChicago) kwisixa sayo esipheleleyo sophahla oluluhlaza. Eminye imifanekiso ekhapha esi sithuba (susa ikhesa phezu kwayo ukuze ufumane iinkcukacha) ibonisa uphahla oluluhlaza kwizakhiwo ezahlukeneyo zaseToronto, kuquka neprojekthi yomboniso efikelelekayo esidlangalaleni kwiqonga leHolo yeSixeko.