Cape T own Wate r Outlook 2018 Upda te d 20 July 2018 De pa rtme - PowerPoint PPT Presentation

Cape T own Wate r Outlook 2018 Upda te d 20 July 2018 De pa rtme nt o f Wa te r a nd Sa nita tio n City o f Ca pe T o wn

Ove r vie w • 2018 ra infa ll to da te a nd b a la nc e o f se a so n fo re c a st • I mpa c t o n da ms a nd ra infa ll sc e na rio s • Wha t ha s c ha ng e d in ma na g ing de ma nd & supply? • T o o e a rly to re la x – imple me nt re c o ve ry pla n to pro vide re lie f witho ut c o mpro mising wa te r se c urity • Re stric tio ns, de ma nd ma na g e me nt initia tive s, re duc e d de ma nd & diminishing re turns • WCWSS rule s a nd re c o nc ilia tio n stra te g y a ppro a c h • Pro viding a ssura nc e o f wa te r supply • Aug me nta tio n c o nside ra tio ns - de te rmining o ptima l a ug me nta tio n vo lume s, timing , so urc e , c o st, re spo nsib ility • E xisting , c o mmitte d a nd future a ug me nta tio n o ptio ns • Summa ry o f c urre nt wa te r o utlo o k

Rainfall in May & June in WCWSS appr oximate ly ave r age

SAWS Rainfall outlook Q3 2018 1. E l Nino / So uthe rn Osc illa tio n (E NSO) is in a ne utra l pha se . 2. L a te st fo re c a sts indic a te a hig h like liho o d (a lmo st a 50% pro b a b ility) o f the de ve lo pme nt o f a n E l Nino e ve nt during spring a nd summe r. 3. I t is still to o e a rly to pre dic t its e xa c t o utc o me during summe r. 4. I t is a dvise d tha t this syste m b e mo nito re d in the ne xt fe w mo nths to de te rmine its impa c t o n the summe r-ra infa ll a re a s. 5. During Jul-Aug -Se p the re a re susta ine d, a lmo st c o untrywide indic a tio ns fo r a b o ve -no rma l ra infa ll, b ut the re is still no c o nfide nc e fo r this pe rio d. 6. T he re is ho we ve r indic a tio ns o f drie r c o nditio ns a lo ng pa rts o f the so uth c o a st, with c o nfide nc e , during Aug -Se p-Oc t a nd Se p-Oc t-No v. 7. Ove ra ll, hig he r tha n no rma l te mpe ra ture s a re e xpe c te d to wa rds Spring a nd b e yo nd. T he re is a pa rtic ula rly hig h c o nfide nc e fo re c a st fo r a b o ve -no rma l te mpe ra ture s o ve r the no rthe rn pa rts o f the c o untry. (a s a t 10 July 2018)

Ave r age r ainfall signific antly r aise d dam le ve ls – 55.8% as at 19 July 2018 1 000 000 110% 97% 100% 900 000 2014 84.1% 90% 800 000 71% 80% 700 000 70% 60.3% 600 000 2015 55.4% Da m le ve ls ~29% tha n in 2017 60% CT L 2 CT L 3 500 000 2016 46.5% 50% 38.4% 400 000 40% 31.0% DWS 45/ 60% CT L 5 2017 300 000 CT L 6 DWS 20% 30% CT L 6B CT L 4 ologic al ye ar CT L 4B 200 000 20% 2018 t 1 Nov 100 000 10% Hydr Star 0% 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018

T he impac t of r ainfall on dam le ve ls if c ur r e nt r e str ic tions r e main 90% We t winte r Pr opose d CAPE T OWN r e str ic tion le ve ls will de pe nd on r e str ic tions 80% pr e vailing in the WCWSS L ong te rm ave rage rainfall 70% 60% Ac tual dam le ve ls 50% 2017 ra infall 40% 30% 50% of 2017 ra infall 20% Dr awdown will var y de pe nding on r e str ic tion le ve l impose d by DWS 10% 31 Oc t e nd of hydr ologic al ye ar 0% 01-JAN-18 01-FEB-18 01-MAR-18 01-APR-18 01-MAY-18 01-JUN-18 01-JUL-18 01-AUG-18 01-SEP-18 01-OCT-18 01-NOV-18 01-DEC-18 01-JAN-19 01-FEB-19 01-MAR-19 01-APR-19 01-MAY-19 01-JUN-19 01-JUL-19 01-AUG-19 01-SEP-19 01-OCT-19 2017 rainfall 50% of 2017 rainfall Average rainfall Wet winter

What happe ne d to Day Ze r o? / Dr ought Monitor ing - 2018 Hydr ologic al Ye ar • T he Da y Ze ro mo nito rpro vide d fo r da m le ve ls b e lo w 40%, b a se d o n ra infa ll simila r to 2017. • I n lig ht o f impro ve d da m le ve ls, the City is e xplo ring ic tions to pro vide re lie f to c o nsume rs while no t inc r e me ntal r e duc tion of r e str c o mpro mising wa te rse c urity.

Dam le ve ls > in 2015: How has this c hange d what we do? • Still to o e a rly to re la x • Dro ug ht ma na g e me nt mo ving to a re c o ve ry pha se • F o c us o n lo ng -te rm re silie nc e • E nsure le sso ns fro m the dro ug ht a re use d to e nsure wa te r se c urity g o ing fo rwa rd • F o rma lise wa te r stra te g y a s it re la te s to wa te r supply & de ma nd, re silie nc e & a da pta tio n, g o ve rna nc e , fina nc ia l susta ina b ility De mand Supply • • Ro lling o ut o f pre ssure ma na g e me nt zo ne s will Ma na g ing da m syste m o ptima lly a c c o rding to syste m c o ntinue until a ll po ssib le zo ne s a re c o mple te d. r ule s ; Pre ssure s a re linke d to re stric tio n le ve ls; • Ma na g ing c a tc hme nts inc luding c le ar ing alie n • Wa te r ma na g e me nt de vic e s will still b e insta lle d in ve ge tation ; a lig nme nt with re stric tio n le ve ls b ut a t a re duc e d • Re vie wing le ve l o f de sir anc e fo r the pa c e ; e d supply assur City (c urre ntly 1:50); • T a riffs will re ma in in pla c e until re stric tio n le ve ls a re • re duc e d a nd ne e d to c o mpe nsa te fo r b o unc e -b a c k De te rmine optimal augme ntation volume s a nd timing unc e rta intie s; a lig ne d with re c o nc ilia tio n stra te g y; • Co mmunic a tio n c a mpa ig ns will c o ntinue , to e nsure • Co ntinue e xisting a ug me nta tio n pro je c ts. re spo nsib le wa te r use .

DE MAND APPROACH HAS MOVE D F ROM DISAST E R T O L ONG- T E RM RE SIL IE NCE SIDE But DWS re stric tio ns a re in pla c e a nd ne e d to b e me t. Ag ric ultura l re le a se s we re limite d to e nsure 60% sa ving . Urb a n re q uire s 45% sa ving ; the c ity ha s a c hie ve d 41% to da te a nd c a n thus no t re duc e wa te r re stric tio ns de spite re c o ve ring da m le ve ls.

F or Cape T own, this me ans that de mand must still be manage d DE MAND SIDE to ge t be low 450 Ml/ day While Ca pe T o wn ha s sig nific a ntly re duc e d its de ma nd (me a sure d he re a s pro duc tio n fro m the tre a tme nt wo rks), fro m a pe a k o f 1200 Ml/ da y in 2015 do wn to ne a rly 500 Ml/ da y, a furthe r re duc tio n in de ma nd is ne e de d to b e lo w 450 Ml/ da y to me e t the 45% sa ving re q uire d b y DWS re stric tio ns. De mand r e duc tion is saving >400 Ml/ day F e b 2017 = 900 Ml/ da y July 2018 = 500 Ml/ da y Ma in de ma nd re duc tio n inte rve ntio ns inc lude : • punitive dro ug ht ta riffs • wa te r ma na g e me nt de vic e s & flo w re stric to rs • a g g re ssive pre ssure ma na g e me nt

DE MAND De mand manage me nt ac tions SIDE 60 000 3000 No Water WMD notifications Weekly Contravention actions • Co ntra ve ntio ns intro duc e d in Oc t 2017 – WMDs insta lle d Number of contravention actions Cumulative Contravention actions 50 000 2500 whe re use >20kl/ mth pe r ho use ho ld; WMD "no water" notifications • F ro m 1 Ja n 2018, this c ha ng e d to insta lla tio ns a t 40 000 2000 ho use ho lds using >10.5kl/ mth; • Ave ra g e ho use ho ld size in Ca pe T o wn is 3.2, a t 50lc d => 30 000 1500 4.8kl/ mth pe r ho use ho ld • Spike in WMD “no -wa te r” no tific a tio ns; 20 000 1000 • Appro xima te ly 15% o f no tific a tio ns re sult in o rde rs – tha t me a ns tha t the ma jo rity o f c a lls lo g g e d a re due to 10 000 500 unde te c te d le a ks a nd ho use ho lds de ple ting the da ily a llo c a tio n a nd a re no t due to insta lla tio n o r me te r issue s; 0 0 08-Oct 22-Oct 05-Nov 19-Nov 03-Dec 17-Dec 31-Dec 14-Jan 28-Jan 11-Feb 25-Feb 11-Mar 25-Mar 08-Apr 22-Apr 06-May 20-May 03-Jun 17-Jun • Sa ving a s a t 10 July 66 ML D a s a t 6 July 2018. • pre ssure re duc tio n 61 ML D • le a k re pa ir fro m re tic ula tio n re pa irs 3.5 ML D • le a k re pa ir fro m inte rna l ho use ho ld le a ks 0.3 ML D • L e a k re pa ir • Pre ssure re duc tio n o n 163 zone s a c ro ss the City. • T he b re a kdo wn o f pre ssure ma na g e me nt is a s fo llo ws: • T o ta l le ng th o f re tic ula tio n a c ro ss the 10 600km • T o ta l le ng th o f c urre nt pre ssure ma na g e d re tic ula tio n: 4 800km (45,3%) • T o ta l le ng th o f re tic ula tio n tha t will b e ma na g e d o n c o mple tio n o f c o ntra c t (inc lude s a ll ne w zo ne s c urre ntly b e ing de sig ne d a nd c o nstruc te d): 6 200km (58,6%)

Cape T own has done r e ally we ll, but fur the r r e duc tion is unlike ly DE MAND SIDE (diminishing r e tur ns) 400 350 Ave r age ur ban me tr os 300 in South Afr ic a: Buffalo City ~270 litr e pp pd Nelson Mandela Bay 250 Mangaung Ekurhuleni Metro 200 City Of Johannesburg City Of Tshwane 150 eThekwini Cape Town Cape T own ~125 litr e pp pd (All metros) 100 50 (base d on litre s pe r pe rson pe r day, population in se r vic e ar e a – Cape T own population ~ 4 million) ‐ 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018