--Shorten our showering time.

3.the 4 taps:
--water from local catchment
--imported water
--newater
--desalinated water

2.Will there be any big changes to the water supply in the future?

Looking to add a fifth “national tap” to Singapore’s existing four, national water agency PUB announced yesterday that it was looking to study the possibility of drawing on “naturally occurring aquifers and groundwater” in the area of the Jurong Formation.

Aquifers are underground layers of water-bearing permeable rock or unconsolidated materials, such as sand, from which groundwater can be extracted.

The PUB has called a three-year consultancy services tender to study the potential of tapping on aquifers and other underground water sources in the western and southern part of the island, which contain rock deposits called the Jurong Formation.

The study will look at the development of groundwater flow models, field investigation programmes and validation studies.

SOURCE: https://www.eco-business.com/news/singapores-fifth-national-tap-may-draw-groundwater/

Singapore and Malaysia have signed four agreements regarding the supply of water from across the Causeway. The first signed in 1927 is no longer in force.¹ Water imported from Malaysia under the other three agreements – signed in 1961, 1962 and 1990 – meets about half of Singapore's water demand.² However, this quantity was reduced after the 1961 pact expired in August 2011. The government has also stated that Singapore can be self-sufficient in water by the time the 1962 and 1990 agreements expire in 2061.³

1927 agreement
Dated 5 December 1927, this agreement was signed between the municipal commissioners of the town of Singapore and Sultan Ibrahim of the state and territories of Johor. It allowed Singapore to rent 2,100 ac (8.5 sq km) of land in Gunong Pulai for the purpose of supplying raw water from the area to Singapore. An annual rent of 30 sen per acre (per 4,047 sq m) was payable on the land but the water was free. Johor set aside an additional 25 sq mi (64.7 sq km) of land and agreed not to alienate any part of this land for the next 21 years without the consent of the Singapore commissioners.⁴ If the latter wanted to reserve any part of this plot for drawing water, they had to give notice to the Johor government and pay an annual rent of $5 per acre.⁵ In return, Johor could obtain 800,000 gallons (3,637 cu m) of treated water from Singapore daily at a rate of 25 sen per 1,000 gallons (per 4.55 cu m).⁶ If Johor required more treated water after 1929, the amount supplied could be increased, but only up to 1,200,000 gallons (5,455 cu m) per day.⁷

1961 agreement
The Tebrau and Scudai Rivers Water Agreement was made between the city council of the state of Singapore and the government of the state of Johor.⁸ Although the agreement was officially signed on 2 October 1961, it had already taken effect on 1 September the previous month.⁹ By then, Singapore was a self-governing state while Malaya was an independent nation.¹⁰ The 1927 agreement was declared void in this document.¹¹

The agreement gave Singapore the full and exclusive right to draw off all the water within the designated land at Gunong Pulai, Sungei Tebrau and Sungei Scudai for a period of 50 years up till 2011.¹² Singapore was to pay an annual rent of RM5 per acre for the land and a charge of 3 sen for every 1,000 gallons of raw water it drew.¹³ Singapore also agreed to provide Johor with a daily supply of treated water up to 12 percent of the raw water it drew, subject to a minimum of four million gallons (18,184 cu m),  and at a price of 50 cents per 1,000 gallons. If the 12 percent provided by Singapore was insufficient, Johor could request for more treated water to be supplied.¹⁴

1962 agreement
The Johor River Water Agreement was signed on 29 September 1962 between the city council of the state of  Singapore and the government of the state of Johor.¹⁵ Valid for 99 years till 2061, the agreement gave Singapore the right to draw 250 million gallons of water per day (1.14 million cubic metres) from the Johor River.¹⁶ In return, Johor was entitled to a daily supply of treated water from Singapore up to two percent of the raw water it supplied.¹⁷

Singapore had to pay rent for the land it used “at the standard rate applicable to building lots on town land”.¹⁸ The water prices remained the same as in the previous agreement – 3 sen per 1,000 gallons of raw water supplied to Singapore and 50 sen per 1,000 gallons of treated water sold to Johor.¹⁹ After Singapore and Malaysia stopped using a common currency in 1973, the prices became denominated in Malaysian ringgit.²⁰

The 1961 and 1962 agreements provided for a price review after 25 years, with arbitration being the agreed course of action if bilateral price negotiations failed.²¹ However, the Johor government chose not to revise the prices at both opportunities, in 1986 and 1987.²²

The Independence of Singapore Agreement (also known as the Separation Agreement) signed between the governments of Singapore and Malaysia on 9 August 1965 guaranteed the 1961 and 1962 water agreements.²³

1990 agreement
This was signed on 24 November 1990 between the Public Utilities Board (PUB) of Singapore and the government of the state of Johor.²⁴ It was supplementary to the 1962 pact and would also expire in 2061.²⁵ A separate document was signed on the same day by the governments of Malaysia and Singapore to guarantee adherence to the agreement.²⁶

Under this agreement, Singapore was allowed to construct a dam across Sungei Linggiu²⁷ to facilitate the extraction of water from the Johor River,²⁸ with Johor setting aside about 21,600 ha (216 sq km) of land for the project.²⁹ Singapore agreed to pay a RM320 million as compensation for the permanent loss of use of the land and its associated revenue, in addition to a premium of RM18,000 per hectare (10,000 sq m) and an annual rent of RM30 for every 1,000 sq ft (per 92.9 sq m) for the land occupied by a water treatment plant and other ancillary permanent works. The cost of building and maintaining the dam would be borne by Singapore.³⁰

In return, Singapore could purchase treated water from Johor generated by the new dam.³¹ This would be over and above the 250 mgd of raw water that it was allowed to draw from the Johor River under the 1962 agreement.³² The price of this additional supply would be calculated based on a fixed formula: the weighted average of Johor's water tariffs plus 50 percent of the surplus from the sale of this water by PUB to its consumers after deducting Johor's price and PUB's cost of distribution, or 115 percent of the weighted average of Johor's water tariffs, whichever was higher.³³

This agreement was a follow-up to the memorandum of understanding (MOU) signed on 28 June 1988 between the two countries' prime ministers at the time: Lee Kuan Yew for Singapore and Mahathir Mohamad for Malaysia. The signing of the MOU was hailed as a breakthrough in Singapore-Malaysia water relations – the culmination of six years of difficult negotiations.³⁴

Beyond 2061
The Singapore government  did not renew the 1961 agreement which expired in 2011.³⁵ To reduce Singapore's dependence on imported water, the government has taken steps to increase the size of the local water catchment area and to build up the supply from non-conventional sources, namely NEWater (reclaimed water) and desalinated water (treated seawater), by setting up water treatment plants in various parts of Singapore. The first two NEWater plants were opened in Bedok and Kranji in 2003.  With the various water projects progressing well, government officials have assured Singaporeans that the country can be self-reliant in water by 2061 if it needs to be.³⁶

SOURCE: https://eresources.nlb.gov.sg/infopedia/articles/SIP_1533_2009-06-23.html

4. Changi Water Reclamation Plant
5. Sembcorp NEWater Plant
SOURCE:
https://www.maser.com.sg/SIEMENSBlowers
https://www.maser.com.sg/kranji-newater-factory
https://www.pub.gov.sg/watersupply/fournationaltaps/newater
https://en.wikipedia.org/wiki/NEWater
http://www.water-treatment.com.cn/plants/list/singapore-ulu-pandan-wrp.htm
https://www.water-technology.net/projects/changi-reclamation/
https://www.sembcorp.com/en/media/media-releases/energy/2010/may/opening-of-singapores-fifth-and-largest-newater-plant-the-sembcorp-newater-plant/

2) Can Singapore survive without the water agreement?

     In short, no. The Water Agreements were guaranteed by the Government of Malaysia in the Separation Agreement signed in 1965 that established Singapore as an independent state. The guarantee was also enacted into the Malaysian Constitution by an Act of Parliament. The Malaysian Constitution was annexed to the Separation Agreement. The Separation Agreement was registered with the United Nations.

     Both countries have to honour the terms of the Water Agreements and the guarantee in the Separation Agreement. Neither Singapore nor Malaysia can unilaterally change them. Any breach of the Water Agreements would call into question the sanctity of the Water Agreements and the Separation Agreement, and can undermine Singapore’s very existence.
SOURCE:
https://www.mfa.gov.sg/SINGAPORES-FOREIGN-POLICY/Key-Issues/Water-Agreements