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The effect of controlled pressure adjustment on consumer water demand in an urban water distribution system
Thesis (MEng)--Stellenbosch University, 2018.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2018
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| _version_ | 1867613768086716416 |
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| access_status_str | Open Access |
| author | Meyer, Daniel (Niel) |
| author2 | Jacobs, H. E. |
| author_browse | Jacobs, H. E. Meyer, Daniel (Niel) |
| author_facet | Jacobs, H. E. Meyer, Daniel (Niel) |
| author_sort | Meyer, Daniel (Niel) |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--Stellenbosch University, 2018. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/103805 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:41:23.238Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2018 |
| publishDateRange | 2018 |
| publishDateSort | 2018 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/103805 The effect of controlled pressure adjustment on consumer water demand in an urban water distribution system Meyer, Daniel (Niel) Jacobs, H. E. Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. Water demand management UCTD Water-supply engineering Water distribution systems Thesis (MEng)--Stellenbosch University, 2018. ENGLISH ABSTRACT: Pressure management is commonly employed as part of water conservation and water demand management strategies in water distribution systems (WDS). Most of the earlier work on this subject focussed on the reduction of water leakage and of burst pipes as a result of pressure reduction, and few studies have been undertaken to investigate the pressure-demand relationship. In this regard, a series of pressure adjustments in three operational district metered areas (DMAs) were successfully planned and conducted to assess the impact of pressure change on the total water demand in each DMA as well as on the water demand of 76 consumers. All three research sites reported a positive relationship between pressure change and consumer demand, where reduced pressure resulted in reduced demand. The impact of pressure on demand varied from one research site to the next. Two significant factors were identified which could influence elasticity of demand to pressure, namely: the presence of on-site leakage and the presence of household plumbing pressure reducing valves (PRVs). For the sites investigated, on-site leakage was one of the main factors behind the pressure-demand relationship and where on-site leakage was excluded the impact of pressure changes on demand was generally found to decrease. The power regression model suggested an elasticity of demand to pressure in the range of ≈0.15 to ≈0.30 where on-site leakage was included, and in the range of ≈0.05 to ≈0.25 where on-site leakage was excluded. The impact of pressure changes on consumer demand may be perceived to be relatively low, but could be partially explained by the presence of household plumbing PRVs. If the pressure to a building is regulated by a household plumbing PRV (often installed on the supply to a hot water geyser) then changes in the WDS pressure are not expected to influence supply pressure at individual end-uses downstream of such a plumbing PRV, unless the WDS pressure is reduced below the setting of the plumbing PRV. The elasticity of demand to pressure (excluding on-site leakage) was in the range of ≈0.05 for DMAs with a high likelihood of household plumbing PRVs and in the range of ≈0.25 for the DMA where fewer properties were expected to have such PRVs. The finding has significant implications for pressure management programmes, suggesting that consumer demand in suburban areas (excluding on-site leakage) may in some cases not reduce notably with relatively large changes in pressure, probably due to the presence of household plumbing PRVs which would have controlled pressure to some end-use points in the home in the first place. The field exercise confirmed that individual consumer demand would not necessarily decrease with reduced pressure, and that the impact of non-technical aspects could surpass pressure-induced change for an individual consumer. A basic but useful approach was proposed to estimate the demand component in the DMA from the flow recording data. The study also highlighted the practical lower limit of pressure reduction in the DMAs investigated, which may be of use for water utilities when planning pressure reduction programmes. AFRIKAANSE OPSOMMING: Waterdrukbestuur word algemeen gebruik as deel van bestuurstrategië vir waterbesparing en wateraanvraag in waterverspreidingstelsels. Die meeste vroeër werk oor hierdie onderwerp het gefokus op die vermindering van waterlekkasies en van gebarste pype deur drukvermindering, en min studies is al gedoen om die verhouding tussen waterdruk en wateraanvraag te ondersoek. In hierdie verband is 'n reeks drukaanpassings in drie operasionele toetsareas suksesvol beplan en uitgevoer om die impak van drukverandering op die totale wateraanvraag in elke toetsarea asook by 76 verbruikers te evalueer. Die resultate by al drie toetsareas wys 'n positiewe verwantskap tussen drukverandering en wateraanvraag, waar verminderde druk lei tot 'n verminderde wateraanvraag. Die impak van druk op aanvraag het gewissel van een area na die ander. iv OPSOMMING Waterdrukbestuur word algemeen gebruik as deel van bestuurstrategië vir waterbesparing en wateraanvraag in waterverspreidingstelsels. Die meeste vroeër werk oor hierdie onderwerp het gefokus op die vermindering van waterlekkasies en van gebarste pype deur drukvermindering, en min studies is al gedoen om die verhouding tussen waterdruk en wateraanvraag te ondersoek. In hierdie verband is 'n reeks drukaanpassings in drie operasionele toetsareas suksesvol beplan en uitgevoer om die impak van drukverandering op die totale wateraanvraag in elke toetsarea asook by 76 verbruikers te evalueer. Die resultate by al drie toetsareas wys 'n positiewe verwantskap tussen drukverandering en wateraanvraag, waar verminderde druk lei tot 'n verminderde wateraanvraag. Die impak van druk op aanvraag het gewissel van een area na die ander. Twee belangrike faktore is geïdentifiseer wat elastisiteit van wateraanvraag deur druk kan beïnvloed, naamlik: die voorkoms van lekkasies op erwe en die teenwoordigheid van huishoudelike drukverminderingskleppe. Lekkasies op erwe het geblyk een van die hooffaktore te wees wat die druk-aanvraag verhouding kan beïnvloed, en waar lekkasies weggelaat is, het die impak van druk op aanvraag gedaal. Die elastisiteit van wateraanvraag deur druk was ≈0.15 tot ≈0.30 waar lekkasies op erwe ingesluit is, en ≈0.05 tot ≈0.25 waar sulke lekkasies uitgesluit is. Die impak van drukveranderinge op aanvraag was relatief laag, maar kan gedeeltelik verklaar word deur die teenwoordigheid van huishoudelike drukverminderingskleppe. As die druk by 'n gebou gereguleer word deur 'n huishoudelike drukverminderingsklep (tipies geïnstalleer by 'n warmwatergeiser) behoort drukverandering in die waternetwerk nie die druk stroomaf van daardie drukverminderingskleppe te beïnvloed nie, tensy die waternetwerkdruk onder die stelling van die drukverminderingsklep daal. Die elastisiteit van wateraanvraag deur druk (uitgesluit lekkasie op erwe) was ongeveer ≈0.05 vir areas met 'n hoë waarskynlikheid van huishoudelike drukverminderingskleppe en ≈0.25 vir areas waar minder sulke drukverminderingskleppe verwag sou word. Die bevinding het belangrike implikasies vir munisipale waterdrukbestuur; dit dui daarop dat verbruikersaanvraag in stedelike gebiede (uitgesluit lekkasie op erwe) in sommige gevalle nie merkbaar gaan verminder met relatief groot veranderinge in druk nie, waarskynlik as gevolg van die teenwoordigheid van huishoudelike drukverminderingskleppe wat in elk geval die druk by sekere watergebruikspunte op die erf beheer. Die studie het bevestig dat individuele wateraanvraag nie noodwendig sal afneem met verminderde druk nie, en dat die impak van nie-tegniese aspekte die impak van drukverandering by 'n individuele verbruiker kan oortref. 'n Basiese maar nuttige benadering is voorgestel om die wateraanvraagkomponent vir ‘n toetsarea uit gemete vloeidata te bepaal. Die studie het ook gewys dat daar ʼn praktiese limiet is vir drukvermindering in die areas wat ondersoek is, wat in ag geneem kan word deur munisipaliteite in die beplanning van drukbestuurprogramme. 2018-02-28T11:47:40Z 2018-04-09T07:09:58Z 2018-02-28T11:47:40Z 2018-04-09T07:09:58Z 2018-03 Thesis http://hdl.handle.net/10019.1/103805 en_ZA Stellenbosch University 79 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Water demand management UCTD Water-supply engineering Water distribution systems Meyer, Daniel (Niel) The effect of controlled pressure adjustment on consumer water demand in an urban water distribution system |
| title | The effect of controlled pressure adjustment on consumer water demand in an urban water distribution system |
| title_full | The effect of controlled pressure adjustment on consumer water demand in an urban water distribution system |
| title_fullStr | The effect of controlled pressure adjustment on consumer water demand in an urban water distribution system |
| title_full_unstemmed | The effect of controlled pressure adjustment on consumer water demand in an urban water distribution system |
| title_short | The effect of controlled pressure adjustment on consumer water demand in an urban water distribution system |
| title_sort | effect of controlled pressure adjustment on consumer water demand in an urban water distribution system |
| topic | Water demand management UCTD Water-supply engineering Water distribution systems |
| url | http://hdl.handle.net/10019.1/103805 |
| work_keys_str_mv | AT meyerdanielniel theeffectofcontrolledpressureadjustmentonconsumerwaterdemandinanurbanwaterdistributionsystem AT meyerdanielniel effectofcontrolledpressureadjustmentonconsumerwaterdemandinanurbanwaterdistributionsystem |