A method comprising: determining a spectral energy ratio as a function of first pressure data acquired during a first time period in which a water flow through a plumbing system of a building is below a flow threshold; determining a multimodal test value as a function of second pressure data acquired during a second time period that includes at least some time during which the water flow through the plumbing system is greater than or equal to the flow threshold; and identifying a type of the plumbing system of the building as a function of the spectral energy ratio and the multimodal test value, wherein: the spectral energy ratio is determined as a numerator divided by a denominator, the numerator is a portion of energy of the first pressure data within a first frequency band that ranges from 0 Hz to a target frequency, and the denominator is a total energy of the first pressure data, the multimodal test value is determined as a function of a difference between two peaks of a histogram of the second pressure data and a minimum between the two peaks such that the multimodal test value = 1 − m P 1 + P 2 , where P 1 is the value of a first peak of the histogram, P 2 is the value of a second peak of the histogram, and m is the value of the minimum of the histogram between the first and second peaks, and the type of the plumbing system of the building is identified as a system that includes a working pressure reducing valve (PRV), a non-functional PRV, no PRV, a well, or a check valve. determining a spectral energy ratio as a function of first pressure data acquired during a first time period in which a water flow through a plumbing system of a building is below a flow threshold; determining a multimodal test value as a function of second pressure data acquired during a second time period that includes at least some time during which the water flow through the plumbing system is greater than or equal to the flow threshold; and identifying a type of the plumbing system of the building as a function of the spectral energy ratio and the multimodal test value, wherein: the spectral energy ratio is determined as a numerator divided by a denominator, the numerator is a portion of energy of the first pressure data within a first frequency band that ranges from 0 Hz to a target frequency, and the denominator is a total energy of the first pressure data, the multimodal test value is determined as a function of a difference between two peaks of a histogram of the second pressure data and a minimum between the two peaks such that the multimodal test value = 1 − m P 1 + P 2 , where P 1 is the value of a first peak of the histogram, P 2 is the value of a second peak of the histogram, and m is the value of the minimum of the histogram between the first and second peaks, and the type of the plumbing system of the building is identified as a system that includes a working pressure reducing valve (PRV), a non-functional PRV, no PRV, a well, or a check valve. the spectral energy ratio is determined as a numerator divided by a denominator, the numerator is a portion of energy of the first pressure data within a first frequency band that ranges from 0 Hz to a target frequency, and the denominator is a total energy of the first pressure data, the multimodal test value is determined as a function of a difference between two peaks of a histogram of the second pressure data and a minimum between the two peaks such that the multimodal test value = 1 − m P 1 + P 2 , where P 1 is the value of a first peak of the histogram, P 2 is the value of a second peak of the histogram, and m is the value of the minimum of the histogram between the first and second peaks, and the type of the plumbing system of the building is identified as a system that includes a working pressure reducing valve (PRV), a non-functional PRV, no PRV, a well, or a check valve. <EOS>