The high scientific standards maintained by Water Supply in their papers owes much to the continuing dedication of the journals' reviewers, who give freely of their time and expertise. IWA Publishing is pleased to pay tribute to this contribution by recognizing those who have participated in the review process. Thus, the Editor in Chief, Editors and Associate Editors of Water Supply acknowledges with particular gratitude the reviewers who have reviewed papers during the period January 2019–December 2019.
| Nurul Aiin Ab Aziz | Hawn-Chung Chu | Jiajie He | Edevar Luvisotto Junior | Mohammad Taghi Serajian |
| Aminuddin Ab Ghani | Yi-Hsueh Chuang | Katherine Heal | Michael Möderl | Tjandra Setiadi |
| Abdallah Abdelfattah | Marco Cifrodelli | Helvi Heinonen-Tanski | Jitka MacAdam | Omid Seyedashraf |
| Wael Abdelraheem | Eoghan Clifford | María Hellmers | Maritza Macias-Corral | C. Sezen |
| Hussein Abdel-Shafy | Ricardo Cobacho | Mehrdad Hesampour | Mohamad Reza Madadi | Isam Shahrour |
| Kaoru Abe | Luciano Coccagna | Wim Hijnen | Anas Makki | Peter Shanahan |
| Amila Abeynayaka | Robin Collins | Ryo Honda | Stefano Mambretti | Himanshu Sharma |
| Akebe Luther King Abia | Andrea Cominola | Khosrow Hosseini | Pedro Manso | Om Prakash Sharma |
| Hassan Aboelnga | Pasquale Contestabile | Jingming Hou | Gustavo Marini | Pramod Sharma |
| Jose Manuel Abreu | Nadim Copty | Guy Howard | João Marques | Weiyu Shi |
| salem Abu Amr | Lucila Coral | V. Hrissanthou | Rui Marques | Ming-Cheng Shih |
| Eyad Abushandi | ME Corman | C Hu | Valentina Marsili | Nobutaka Shirasaki |
| Olusegun Adeoti | Benito Corona Vasquez | Donggen Huang | Nuno Martins | Gyan Shrivastava |
| Arash Adib | Juana Cortés Muñoz | Yi-Chu Huang | TM Martins | Rituraj Shukla |
| Mansoor Ahammed | Joseph Cotruvo | Yuk Feng Huang | Costantino Masciopinto | Praveen Sihag |
| Gamila Ahmed | Carmine Covelli | Stewart Husband | Fhumulani Mathivha | Dai Simazaki |
| Seval Akal Solmaz | Enrico Creaco | Taisen Iguchi | Antonio Matos | Antonietta Simone |
| María Alarcón Herrera | Jonathan Crockett | Toshiaki Iida | Yoshihiko Matsui | Gurmeet Singh |
| Francesco Aletta | Jan Cromphout | Takanobu Inoue | Elena Matta | Saikat Sinha Ray |
| Eleftheria Alexandri | Marco Antonio Cruz Chavez | Unai Iriarte | Harri Mattila | Siti Murniningsih Siti Murniningsih |
| Mahmoud Al-Hindi | Abdelkrim Dahmen | Anchal Jain | Catalina Maya | Leszek Sobkowiak |
| Farhad Alizadeh | Luiz Daniel | Sanghyun Jeong | Larry Mays | Maria Do Carmo Sobral |
| Paola Almeida-Guerra | Tina Dasic | Vincent Ji | Edward McBean | Hans-Christian Sorge |
| Mena Alsawaf | Giovanni De Feo | Rui-bao Jia | Md Azlin Md Said | Javier Soriano |
| Stefano Alvisi | Mauro De Marchis | Shuh-Ren Jing | Silvia Meniconi | Joaquim Sousa |
| Tony Amato | Nilo de Oliveira Nascimento | Franca Jones | Gérard Merlin | Andrew Spiegel |
| Muhammad Amin | Francesco De Paola | Ron Jong | Carsten Meyer | K Sreelash |
| Andreas Andreadakis | Ianis Delpla | V. Jothiprakash | Jose Mierzwa | Stefan Stanko |
| Andreas Angelakis | Abel Dembélé | Miodrag Jovanovic | Ivan Milojković | Philipp Staufer |
| Barbara Čenčur Curk | Dhammika. DeSilva | Talis Juhna | Joong-Hyuk Min | Rodney Stewart |
| Y. Arai | Vittorio Di Federico | Tim Julian | Gholamreza Mirzavand | Jian-Ping Suen |
| Rosa Araujo | Fabio Di Nunno | Byung-Moon Jun | Steve Mitchell | Chaisri Suksaroj |
| R Arunkumar | Santino Diberardino | Jose Luis Jurado Baizaval | Abu Bakar Mohamad | Prabhata Swamee |
| Rupak Aryal | Heiko Diestel | Roger König | S Mohan | Maciej Szwast |
| Richard Ashley | Berge Djebedjian | Herbert Kalibbala | Mohd Azlan Mohd Yusoff | Hideyuki Tadokoro |
| Azize Ayol | Dejana Djordjevic | Norashikin Kamal | Kazuro Momii | Amin Talei |
| Mustafa Tamer Ayvaz | Hong Do | Takashi Kameya | Laura Monteiro | Xiangming Tang |
| Hazi Azamathulla | Slaven Dobrovic | Riitta Kamula | José de Jesús Mora Rodríguez | Mukesh Tiwari |
| Juan Baeza | Emmanuel Donkor | Vasilis Kanakoudis | Mauricio Morel | Carla Tricarico |
| Abdolreza Bahremand | Caetano Dorea | Hyo Kang | Marco Antonio Moreno Leon | Jelena Trickovic |
| Xiaohui Bai | Ming Dou | Sameh Kantoush | Maruf Mortula | Stavroula Tsitsifli |
| Aminuddin Baki | Walter Dragoni | Anastasios Karabelas | Habib Muhammetoglu | Antal Tungler |
| Sengottuvelan Balasubramanian | Renato Drusiani | Ethem Karadirek | Syed Muztuza Ali | Mustafa Turan |
| James Ball | Xinqiang Du | Theodoros Karakasidis | Mohammad Najafzadeh | Vasilios Tzanakakis |
| Bijit Banik | Huan-Feng Duan | Md. Karim | Umamahesh Nanduri | Camelia Ucenic |
| Brian Barkdoll | Sophie Duchesne | Barbara Karleusa | Ahmed Kabashi Nassereldeen | Wolfgang Uhl |
| Andrew Barton | Alison Duffy | Bryan Karney | Ines Navarro | Taro Urase |
| Isabelle Baudin | Mawuli Dzakpasu | Konstantinos Katsifarakis | Valentin Nenov | Alhassan Usman |
| John Bavor | Mauricio Dziedzic | Yoshinori Kawase | Roman Neunteufel | Babak Vaheddoost |
| Gianfranco Becciu | Shinya Echigo | E. Keramaris | Jeffrey Newman | Rajendra Vaidya |
| Miray Bekbölet | Alper Elçi | Peter Kern | Tze Ling Ng | Meine van Dijk |
| L Ben Ayed | Mohammad Nabil Bahgat El-Nesr | Wilawan Khanitchaidecha | Bruno Nguyen | Gerard van Houwelingen |
| Hanane Benqlilou | Laszlo Erdei | Sungwon Kim | Thi Phuong Nga Nguyen | Peter van Thienen |
| Luigi Berardi | Mathias Ernst | Weonjae Kim | Salvatore Nicosia | Jakobus van Zyl |
| Anton Bergant | Eleazar Escamilla Silva | Gregory Kleinheinz | Vahid Nourani | Davy Vanham |
| Walter Betancourt | Saeid Eslamian | Natalia Klymenko | Geoff O'Loughlin | Lampros Vasileiadis |
| Haq Bhatti | Vicent Espert | Kenichiro Kobayashi | Grace Oluwasanya | Ioanna Vasiliadou |
| Yanhong Bian | Shibiao Fang | Joerg Koelbl | Pinar Omur-Ozbek | Dimitris Vayenas |
| David Blackwood | Franz Fardin | Yanlong Kong | Gideon Oron | Liesbeth Verdickt |
| Tobias Bleninger | David Ferras | Akechai Kongprajug | Philip Orr | Paola Verlicchi |
| Jessica Bohorquez | Joao Ferreira | Derya Y Koseoglu-Imer | Avi Ostfeld | Kris Villez |
| Marc Boncz | Joachim Fettig | Margaritis Kostoglou | Anna Palla | Bojana Vujović |
| Sara Bonetta | Brian Finlayson | Witold Krajewski | Francis Pamminger | Patryk Wójtowicz |
| Silvia Bonetta | Attilio Fiorini Morosini | Svetislav Krstić | Feng Pan | Gen-Shuh Wang |
| Paola Borella | Lloyd Fisher-Jeffes | Bimlesh Kumar | Manish Pandey | Hongrui Wang |
| Silvena Boteva | Hans-Curt Flemming | Sangeeta Kumari | Olga Pappa | Hongyu Wang |
| Noureddine Bouaicha | Gislaine Fongaro | Goffredo La Loggia | Miguel Angel Pardo Picazo | Xie-Kang Wang |
| Cristiana Bragalli | Luigi Dante Franchioli | Susanne Lackner | Hyung-Gyu Park | Xihua Wang |
| Kevin Bral | Torsten Franz | Mitchell Laginestra | Alison Parker | Yun-Hai Wang |
| Lena Breitenmoser | Daniela Fuchs-Hanusch | Chin-Hsing Lai | Roberto Parra | Muhammad Waqar |
| John Hagan Brown | Takeshi Fujino | Chun-Hsi Lai | Abbas Parsaie | Malcolm Watson |
| Brian Brownlee | Takahiro Fujioka | Abderrahim Lakhouit | Miguel Pena-Varon | Jannis Wenk |
| Bruno Brunone | Taku Fujiwara | Daniele Lantagne | Andrea Perez | Sally Weston |
| Steven Buchberger | Graham Gagnon | Bruno Lartiges | Simone Persiano | Wanpen Wirojanagud |
| Rodrigo Bueno | Catherine Galey | Daniele Laucelli | Dana Petcu | Maria Wirth |
| Jedrzej Bylka | Panagiota Galiatsatou | Markus Lechner | Athit Phetrak | Dominique Wolbert |
| Enrique Cabrera Marcet | Amir Gandomi | MarÃa Ledesma | Brett Phillips | Małgorzata Wolska |
| L.-Y. Cai | Naiyun Gao | Charles Lee | Stefania Piazza | Jianyong Wu |
| Şule Camcıoğlu | Lucas Garcia | Hye-Jin Lee | Katarzyna Pietrucha-Urbanik | Chang-lai Xiao |
| Alberto Campisano | Rudy Gargano | JiWan Lee | Olivier Piller | Wei Xing |
| Shengle Cao | Irene Garousi-Nejad | Jun Lee | Sandhya Rao Poleneni | Jiale Xu |
| Yongqiang Cao | Fabio Garzon | Tsu-chuan Lee | Marie-Noëlle Pons | Qiang Xu |
| Caterina Capponi | Govert Geldof | Angelo Leopardi | Dusan Prodanovic | Süleyman Yüce |
| Maria Adriana Cardoso | Sanda-Carmen Georgescu | Andrija Lesar | Valeria Puleo | Ali Yadollahpour |
| Irene Carra | Pantazis Georgiou | Daphne Lewarne | Raido Puust | Teshome Yami |
| Luis Castillo | Mahnaz Ghaeini-Hessaroeyeh | Cong Li | Xuepeng Qian | Chou-Ping Yang |
| Ignacio Cazcarro | Spyros Giakoumakis | Ping Li | Tian Qin | Zhongping Yang |
| Sudip Chakraborty | Thomas Gillogly | Simeng Li | Claudia Quintiliani | Stavros Yannopoulos |
| Shu-Chi Chang | Brent Gilpin | Warunsak Liamlaem | John Radcliffe | Jian Ye |
| Barkha Chaplot | John Glaser | Roland Liemberger | Ahmed Rahmani | Nese Yilmaz |
| Bambos Charalambous | Alex Godoy-Faundez | Fang Yee Lim | Mohammad Rashki | Baoling Yuan |
| Malay Chaudhuri | Sudha Goel | Po-Hsun Lin | Upaka Rathnayake | Willem Jan Zaadnoordijk |
| Christian Chauret | Fatma Gohary | Zhulu Lin | Andrea Rechenburg | Zhenxing Zang |
| Baiyang Chen | Modreck Gomo | Dey Litan | Luisa Reis | Hangjun Zhang |
| Chia-Yang Chen | José Gonçalves | Fang Liu | Anacleto Rizzo | Jin Zhang |
| Guowei Chen | Rebeca González-Villela | Haixing Liu | Paolo Roccaro | Xiang Zhang |
| He Chen | Marjan Goodarzi | Wen-Cheng Liu | Luis Rodríguez-Gómez | Feifei Zheng |
| Wei-Hsiang Chen | Jan Gregor | Zhiquan Liu | Michele Romano | Zhang Zhiming |
| Chen Cheng | Neil Grigg | Lorena Liuzzo | Srdjan Roncevic | Zhenming Zhou |
| Italo Chiffelle | Xinjian Guan | Joan Llorens | Ehsan Roshani | Dejun Zhu |
| Pei-Te Chiueh | Xinlei Guo | Jenyuk Lohwacharin | Oliver Saavedra | Ottavia Zoboli |
| Kyung-sook Choi | Akira Hafuka | Paola Lombardo | Raquel Sabogal | Alyaa Zyara |
| Kangmin Chon | Ivan Halkijevic | Sandro Longo | Miquel Salgot | |
| Florence Choo | Sam Hancock | Moez Louati | Ricardo Santos | |
| Cristiano Christofaro | M. Hansen | Hui Lu | Hamed Sarkardeh | |
| Constantinos Chrysikopoulos | Khondoker Hassan | Hao Luo | Manfred Schuetze |