Document and Entity Information	6 Months Ended
	Jul. 01, 2012	Jul. 31, 2012 Class A Common Stock	Jul. 31, 2012 Class B Common Stock
Entity Registrant Name	WATTS WATER TECHNOLOGIES INC
Entity Central Index Key	0000795403
Document Type	10-Q
Document Period End Date	Jul. 01, 2012
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		27,764,589	6,953,680
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q2