Water Resources Management in Brantas River Basin

June 5th, 2017

Putika Ashfar Khoiri

putika@civil.eng.osaka-u.ac.jp

Brantas River Basin Overview 1

Principal water usage 2

IrrigationConsume 20% of annual discharge of the river and 42 % (907.000 Ha) irrigated land in East Java is within Brantas Basin

IndustryUse for industrial use and port in SurabayaRaw water for industry supplies 159 mm3/year (in 2011)

Domestic water supplyRaw Water for Domestic Supply = 288 mm3/year

Hydroelectric Power Producers

Water Management Issues 3

Land-use

In 2000 the Brantas Basin made up 32% of East Java’s land area

Populations

The main sources of water of 9 regencies and 5 municipalities

Growth of industrial and housing area

All require water supply Citizen in Keputih (Surabaya) buy water from water tank in drought season

Water Management Issues 4

Floods and drought

• Floods and drought occurs annually due to lack of adequate infrastructure to regulate water

• How to save water during rainy season and release it during dry season

Rungkut area in Surabaya during rainy day January, 12 2017

Problems causes

1. Deforestation and land-use change

2. Inadequate capacities of the river in the middle and lower reach

3. High level of sedimentation impacting the river morphology problem

4. Poor maintenance of infrastructure and lack of funding

Recent Issues 5

1. Changes of the river bed of Brantas channel due to sediment deposition in upstream area, sand extraction in the middle and lower reach

2. Large quantities of light and visible volcanic ash reached the mainstream from Mount Kelud and Mount Semeru induced riverbed rise

3. The presence of mud disaster in Sidoarjo, a nearby municipality from Surabaya increasing river discharge entering Surabaya City

Sand mining activity Citizen riding a motorcycle across the river after Mount Kelud eruption

Vulcanic ash at JuandaInternational Airport Surabaya,

Mud disaster in Sidoarjo area

Development History 6

around the late 1840's the Dutch colonial day

around the late 1950's

Begin at 1956

Indonesian government and Japan

Flood control and water utilization projects such as the construction discharge channel and small-scale hydroelectric power stations. Included irrigation facilities , roads and bridges.

The structures is dilapidated because of lack of maintenance, Indonesia's financial problem after independence and great floods in 1954-1955

Nejama Diversion Tunnel (South Tulungagung Drainage)

Asahi Shinbun (August 31, 1960) “Successfull Reparations Work in Indonesia” . The tunnel heading was penetrated and lining using concrete, and it also become Indonesia's most productive rice growing region. The construction cost of US$ 2 million could be repaid in one year

Development History 7

1945

1961 MASTER PLAN 1 Flood control by constructing dams in upper reaches

1969-1994

Change due to President regimeFrom fisrt to second president

Rice production self sufficiency

Indonesia’s independence

1973 MASTER PLAN 2 Irrigation developement

1985 MASTER PLAN 3 Industrial and urban development by emphasis water supply for domestic and industrial use

1998 MASTER PLAN 4 Management conservation of water resources

End of second president regime2004-now NEW MASTER PLAN ?? Integrated watershed

management

Fund sources : Japanese reparation (JR)Overseas Economics Cooperation Fund of Japan (OECF)Government of Indonesia (GOI)Asian Development Bank (ADB)International Bank for Reconstruction and Development (IBRD)

(JR, OECF, GOI)

(OECF, GOI, ADB)

(IBRD, GOI, ADB)

(IBRD, GOI, ADBJR)

Development History 7

Development History 7Benefits of Master Plan 8

Benefits of development :

1. Estimate protection against 50 year flood2. The 233 Mw capacity of hydropowerplants producing around 1 billion kwH of energy every year3. Supply around 300 Mm3 per year raw water for drinking and for industries4. Total area of paddy irrigated from Brantas river system is around 345,000 ha. In the dry season,

irrigated agriculture consumes approximately 80 percent of the available water in the river. Since 1989 it can supply more than 30 percent of national flood production.

River discharge control Volcano debris control by sabo dam Karangkates Hydropower

Development History 7Water management authority and sharing 9

1. Lisencing

2. Dry and raining season operation rules

• If any institution want to take the water from Brantas River, must ask for a lisence from the local government.

• Technical information is important to keep on water demandIrrigation (80%)Drinking water, industries , fishpond and city flushing, etc (20%)

Dry season (June-November)

User water demand

Local government

Weather forecasting, simulation

Draft of operation rule

Vicegovernor

Approval

Rainy season (December-May)

Operation rules to control floods

Development History 7Condition of water facilities and infrastructure 9

Catchment areaIncreased sedimentation from reservoirs, more erosion, and a lowering of the water table including complete exhaustion. Sedimentation occurs because of the damage to the river upstream

Solution : Green belt -> reforestation in river region

Reservoirs

The impaired capacity of the reservoir can affect flood control attempts and can also reduce raw water supply for the customers.

Solution : Dredging and flushing sediments at reservois

(*) Effective Storage Capacity of the Reservoirs

Development History 7Condition of water facilities and infrastructure 9

Periodic Dams inspection

DAMS

(*) They conducted an investigation by using GPR (Ground Penetrating Radar) in the effort to discover and study existing crack lines and to ascertain their depths.

Development History 7Improvements 10

To support watershed management, regulations about land use conservation must be implemented to minimize land use conversions from green and open spaces to built up areas

Examples of method that can be implemented to reduce run-off to the main river are

1. Rehabilitation of forest in catchment areas

2. Construction of sub-channel and drainage wells

3. Reconstruction of riverbank

Development History 7Improvements 11

Irrigation

Irrigation channel depth became shallow because of sedimentation

river normalization and irrigation channel improvements

Flood control

Normalization of river to enhance the capacity of the river and retarding basin by Ministry of Public Work

Flood control and reducing inundation area

Development History 7“One river, one plan, one management” 12

Operated by permanent institutionProfessional staff and adequate budget

Maintenance of structures

• Dam• River• Tunnel

Upper watershed management

• Reforestation• Plot land use

planning

Water quality management

• Water allocation ( agriculture, drinking water and inductries, electricity, tourism, fishery, transportation• Source of pollutants• Pollution monitoring• Public awareness

Flood Management

• Structure operation rules

• Real time data