Apartment Cmplexes and Water Cnservatin in the City f Davis By Nicle Dunkley, Sam Mffitt, Janna Ortiz, and William Wang Abstract Our prject analyzes the water use f apartment cmplexes in the City f Davis. We cmpared this data t the ttal water use f Davis. After that, we made predictins abut the reductin f water use fr the city due t the drught. Recently, the State Water Resurces Cntrl Bard (SWRCB) prpsed mandatry standards f water reductin fr all cities and municipalities in Califrnia. Davis is in the 7th tier and is required t reduce its water use by 28%. We estimated that Davis wuld have t reduce their ttal water use frm 50,721 gallns per persn per year t 36,519 gallns per persn per year. We cmpared this finding t what we calculated fr apartment cmplex reductins and realized that apartments wuld als have t reduce their water use by 28%. Yet, it was difficult t make any brad cmparisns and assumptins because we were limited by the amunt f apartment cmplexes respnded t ur request fr data. Mst likely due t the drught and strict water regulatins, apartment managers were hesitant t release infrmatin t us. Intrductin Davis is a unique city in many ways. Largely due t the lcatin f UC Davis, 43% f husing units in the City f Davis are in multi-unit cmplexes; this is much higher than the natinal average f 26% (accrding t the American Cmmunity Survey data at census.gv). Mre than half f Davis residents live in rental units. Because apartment cmplexes accunt fr such a large prtin f the Davis ppulatin s husing accmmdatins, and because it is ptentially easier t reduce water use amng apartment cmplexes than amng hmewners, we have decided t fcus n apartment water usage in Davis. We assume that it wuld be easier t implement water reductins amng apartment cmplexes than amng hmewners fr several reasns. Primarily, the cmplex manager
represents dzens f individuals, and it is easier fr city fficials t cnvey a prgram t a limited number f individuals (cmplex wners) than the entire ppulatin. Additinally, apartment cmplexes mre carefully maintain their landscaping, laundry, and ther verhead water systems than hmewners, s it may be easy t make cuts in these areas. Finally, apartment cmplexes are a business, s if they see benefit in reducing their water cnsumptin (mnetary r image-based) then they will, whereas hmewners have less mtivatin. Apartment cmplex water use is a part f urban water use. Urban water use is defined as the use f water fr [all] urban purpses, including residential (by the Califrnia Department f Water Resurces) and is cmprised f bth indr use (shwers, tilets, laundry, etc) and utdr use (primarily landscaping irrigatin). Urban water use accunts fr 10% f Califrnia s ttal water usage (Lecture, Sandval, April 2015). It is imprtant fr residents and prperty wners t understand hw much water they are cnsuming s that changes can be made t cnserve water with the nset f climate change (leading t drughts and a limited water supply). Objective The main gal f ur prject is t predict hw apartment cmplexes in Davis will change their water use in respnse t the drught. Our bjectives t achieve ur gal is as fllws: Determine urban water use f apartment cmplexes in Davis Cmpare that water use t the City f Davis water use WUPC, Ttal Urban Water Use Estimate future reductin f water use based n infrmatin frm the State Water Resurces Cntrl Bard T achieve the first bjective, we cntacted varius apartment cmplexes in Davis via email and phne. In ding this, we asked the apartment managers fr their water use data. Only tw apartment cmplexes respnded t us and willingly gave us the requested infrmatin. The
remaining cmplexes we cntacted either didn t respnd r refused t give us infrmatin. Next, we cmpiled ur data in an excel spreadsheet. Then, we calculated the WUPC and Ttal Water Use fr the cmplexes and cmpared ur results t the City f Davis. Finally, t achieve ur main gal, we gathered mandatry water use reductin data fr the City f Davis frm the State Water Resurces Cntrl Bard. The SWRCB determined that the City f Davis had a mandatry reductin f 28% f their ttal water use fr cnserving water in the drught. With this standard, we were able t estimate hw much apartment cmplexes in Davis wuld have t reduce their water use by (in prprtin t hw much water they cnsume cmpared t Davis as a whle). Hypthesis As lng as ppulatin increases, demand will always increase. Hwever, we believe that the supply f water will decrease in Davis due t the state enfrcing mandatry water cnservatin regulatins. Based n the State Water Resurces Cntrl Bard regulatins, we expect Davis apartments t reduce water use in the future by 5%. S if ppulatin cntinues t increase and the drught causes further reductins in water use, then Davis will have t find a way t efficiently supprt water demand. Data Surces We cllected data via phne calls and emails frm varius apartment cmplexes in Davis. Out f 144 cmplexes, nly tw were willing t release infrmatin t us. In additin, we fund infrmatin abut Davis water use nline. Our cllected data is as fllws: City f Davis Ttal ppulatin 66205 Ttal water use 3358 millin gallns per year Apartments
The Clleges at La Rue 197 Units 10,080,000 gallns per year Russell Park Apartments 200 Units 4,140,000 gallns per year Ttal Apartment Cmplexes in Davis 144 apartment cmplexes 710,000,000 gallns per year Unfrtunately, we were nly able t receive data frm tw cmplexes in Davis. We did, hwever, cntact multiple apartment cmplexes (listed belw) t try t receive data. Apartment Aggie Square Almndwd Alvarad Parkside Alvarad Sunset Casitas Chaparral Chautauqua The Cllege Funtain Circle LaSalle Russell Park West Village Respnse nne nne nne nne nne Managed by Tandem...prvided data fr ther prperties but nt this ne Managed by Tandem...prvided data fr ther prperties but nt this ne Managee by Tandem, data prvided Managed by Tandem...prvided data fr ther prperties but nt this ne nne Managed by Tandem, data Prvided Nne Methds and Assumptins The fllwing is a step-by-step prcess f ur prject: Step 1: phne interviews/emails t apartment cmplexes Step 2: cmpile data
Step 3: using excel, similar t Exercise #1, calculate WUPC and Ttal Water Use and cmpare t the City f Davis Step 4: estimate future reductin in water usage based n SWRCB standards After cmpiling all f ur data we used excel t calculate WUPC, ttal water use, and t estimate water reductin amunts. First, we calculated water use per capita per year by dividing the ttal water use by the expected ttal ppulatin. Then, we multiplied the result by 0.72 t get the expected water cnsumptin after the 28% water use. Fr these calculatins, we assumed that there were tw peple per unit (apartment) fr bth apartment cmplexes. We als assumed that the average apartment cmplex has abut 200 units per cmplex. Calculatin/Results Water per capita fr entire Davis City: 3,358,000,000(gallns/year)/66205= 50721 gallns per persn per year Water use per capita in The Clleges 10,080,000(gallns/year)/(197*2) = 25583 gallns per persn per year Water use per capita in Russell Park 4,140,000(gallns/year) / (200*2) =10350 gallns per persn per year Average Water use per Capita in Davis Apartment Cmplexes 710,000,000 (galln/ year) / 144 (ttal # f apartments) / 400 (expected resident / apartment site)= 12326 gallns per persn per year WUPC after 28% deductin Davis City: 50721*(1-.28)= 36519 gallns per persn per year The Clleges: 25583*(1-.28)=18420 gallns per persn per year Russell Park: 10350*(1-.28)= 7452 gallns per persn per year
Figure 1, shwing the cmparisn f each categries water usage with and withut the 28% mandatry deductin. Cnclusins We were unable t gather enugh relevant data t accept r reject ur hypthesis, hwever we did ntice sme trends amng the data. The average resident at the Clleges and Russell Park uses half as much water as an average Davis resident. We had hped t be able t separate inside and utside data, t analyze whether this difference is due t landscaping r residents habits, hwever nt enugh data was prvided fr this analysis. Frm the data we did receive, we were able t make predictins abut the amunt f water use reductin that apartment cmplexes and the City f Davis need t implement. Overall, Davis needs t reduce its water use by 36,519 gallns per persn per year. We hypthesized that apartment cmplexes wuld have t reduce their usage by a fractin f the 28% standard based n the prprtin f water use f apartments in Davis. We estimated this amunt t be 5%, hwever, this is nt the case. If the city f Davis as a whle wants t reduce their ttal water use
by 28%, everyne in Davis - businesses, hmewners, agriculture, and apartment cmplexes - has t als make a reductin in their water use by 28%. Therefre, we estimated that The Clleges and Russell Park have t reduce their water use by 18,420 gallns per persn per year and 7,452 gallns per persn per year, respectively. Because we nly fund data frm tw ut f the 144 ttal cmplexes in Davis, we cannt make any assumptins abut ttal apartment cmplex water reductin as it wuld likely be inaccurate. Recmmendatin/Limitatins During ur data cllectin prcess we experienced many difficulties. Althugh we cntacted dzens f apartment cmplexes within Davis, ultimately we nly heard back frm ne prperty management cmpany (wh nly prvided data fr tw f their many lcatins). Data was difficult t gather fr several reasns: thse at the receptin desk ften did nt knw the answer t ur questins, and wuld pass ur questin n; after this we wuld nt hear back. It is likely that apartments did nt reprt their data t us because ur questins gt lst in the cmmunicatin chain, r ur inquiry was deemed unimprtant t respnd t, hwever it is als pssible that sme apartments d nt cllect r mnitr their water use data (and did nt respnd because there was n data available), r it is pssible that apartment cmplexes did nt want this data t be made public (if they feared that they used a disprprtinately high amunt f water). Apartment cmplexes that did respnd t ur request nly released ttal water use fr the prperty, hwever use per unit may be useful t measure, as well as maintenance water use, and indr vs. utdr use; it is likely that apartment cmplexes d nt recrd this data, r place high value n it. Whatever the reasn fr these respnses (r lack theref), this lack f data is smewhat alarming. Because the city water department cannt give ut data n individual users, and
because individual users will nt self-reprt, minimal data is available fr researchers (and thus, minimal data is available fr use in plicy frmatin). We wuld recmmend a better public database fr water use prvided by the city. If the city culd further break dwn water use by ther factrs (such as single vs. multi family hmes, rental units versus wned units, area f Davis, etc.) then mre analysis culd be dne t determine differences between these factrs. As f nw water use data is nly available fr the city as a whle. Additinally, we wuld recmmend that the water bard make clear t cnsumers that tracking f yur wn water use is a vital step t reducing water use, especially fr apartment cmplexes wh may be able t initiate prgrams t help residents reduce if they were t determine that they use a substantial amunt f water. If we were t cnduct further analysis in the future it wuld be useful t cntact hmewners as well as apartment cmplexes. We had riginally chsen apartment cmplexes because we knw a large percentage f the Davis ppulatin lives in apartments, and because we hypthesized thse apartments wuld mre diligently track their water use and initiate reductin prgrams than hmewners. Our assumptin des nt seem t be the case, hwever. Additinally, single-family hmes use mre water per capita than an apartment unit, s cllecting data n these users wuld be valuable. We had determined that there were t many huses in Davis t get an accurate sample size surveyed in the time alltted fr this prject, hwever we may have had mre success surveying hmewners than relying n apartment cmplexes.
References City f Davis Mandatry Water Waste Restrictins, 2014 <http://water.cityfdavis.rg/watercnservatin/drught>. City f Davis Ppulatin and Husing 2010, <http://cityfdavis.rg/abut-davis/ppulatin-andhusing>. State Water Resurces Cntrl Bard. <http://www.waterbards.ca.gv/waterrights/water_issues/prgrams/drught/dcs/emerg ency_regulatins/supplier_tiers_20150428.pdf>. Tandem Prperty( 2015) The Clleges and Russell Park Water Demand US Census (2013), DEMOGRAPHIC CHARACTERISTICS FOR OCCUPIED HOUSING UNITS 2009-201, American Cmmunity Survey 5-Year Estimates <http://factfinder.census.gv/faces/nav/jsf/pages/index.xhtml>.