Document and Entity Information	3 Months Ended
	Mar. 29, 2015	May 04, 2015
Entity Registrant Name	WATTS WATER TECHNOLOGIES INC
Entity Central Index Key	0000795403
Document Type	10-Q
Document Period End Date	Mar. 29, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Class A
Entity Common Stock, Shares Outstanding		28,389,517
Class B
Entity Common Stock, Shares Outstanding		6,479,290