Water in the built environment

In 1981 the geographer Roger Ulrich showed 60 colour slides in three sets matched for information rate: nature with water, nature dominated by vegetation and urban scenes with neither. On the two pleasantness scales the water slides averaged 4.93, the vegetation slides 4.48 and the urban slides 2.72, with 86 ratings behind each set. Alpha amplitude ran higher during both nature sets than during the urban one. Water held attention and interest longest of the three.

Water inside a workplace is studied less often than the sight of water outside one, but it has been studied. The acoustics researcher Zanyar Abdalrahman and Galbrun ran two laboratory experiments, acoustic simulations and field tests on water features in open-plan offices in 2020. Against irrelevant speech held at a constant 48 dBA, people preferred water sounds between 42 and 48 dBA, and 45 dBA worked best. Adding a visible water element to the sound improved perception of the acoustic environment by up to 2.5 times. In the field the water sounds cut distraction and privacy distances significantly, and clusters of desks gained more than rows of them. Abdalrahman and Galbrun conclude that water masks speech through the information it adds rather than the energy it adds.

The mental health researcher Nicol Bergou took the question into daily life in 2022. 299 people answered a smartphone prompt three times a day for a fortnight, 7,975 assessments in all, and 87 of them had a diagnosis of mental illness. Having visited a canal or river in the previous 24 hours raised reported wellbeing by 1.25, 1.35 and 0.86 points at the three thresholds measured, each at p below 0.05. Being near a canal or river beat being in a green space. The effect held for people with a diagnosis and for people without one.

The geographer Su-Hsin Lee put 20 office workers and 20 retirees into 360-degree simulations of a forest stream, a waterfall and a beach in 2025. The stream was the only scene that raised positive affect, self-esteem in particular, while lowering depressive mood. Streams and beaches both cut systolic blood pressure. The retirees relaxed physiologically and the office workers gained more emotionally.

One finding runs the other way. When the architecture researcher Heba Abdou surveyed Egyptian workplaces, water features sat at the bottom of the ranking of biophilic elements, with a small but significant negative correlation to reported focus and creativity at r = −0.142 and p = 0.004. It is the only element in that survey to come out below zero.