The 2014 Estimates of National Expenditure pegs total department spending at R12.5bn next year, R16.1bn in 2015/16, and R17.2bn in 2016/17.
"The spending focus over the medium term will be on providing bulk infrastructure for water and waste water treatment works, which link water sources to local government infrastructure."
Of the total R45bn to be spent over this period, about R28bn is earmarked for the department's regional implementation and support programme, and about R11bn for its water infrastructure management programme.
The provision of water and sanitation to households has been under the spotlight in recent months, following a spate of service delivery protests.
In his budget speech on Wednesday, Gordhan, referring to President Jacob Zuma's State of the Nation address delivered a fortnight ago, noted that the protests "are a sign that our people want government to quicken the pace of delivery of housing, water and sanitation".
According to the estimates document, skills shortages continue to plague the department.
"At the end of November [last year], the department had a funded establishment of 4 261 posts, with 219 additional to the establishment and 491 vacant.
"The vacancies were due to the difficulty experienced in attracting people with the critical and scarce skills necessary to perform vital tasks, which is why the department uses consultants when required."
Spending on consultants was expected to increase from R362.3m next year (2014/15), to R477.9m in 2016/17.