Below is the description of the bridge which I found on the web:
The Rainbow Fountain (Korean: 달빛무지개 분수) is the world's longest bridge fountain that set a Guinness World Record with nearly 10,000 LED nozzles that run along both sides that is 1,140m long, shooting out 190 tons of water per minute. Installed in September 2009 on the Banpo Bridge, Seoul mayor Oh Se-hoon praised that the bridge will further beautify the city and showcase Seoul's eco-friendliness, as the water is pumped directly from the river itself and continuously recycled. The bridge has 38 water pumps and 380 nozzles on either side, which draw 190 tons of water per minute from the river 20 meters below the deck, and shoots as far as 43 meters horizontally.
There is music accompanying the show.
Two complexes near the Banpo Hangang park.
Normal looking bridge. Wait for a while. Another 5 minutes, the show will start.
The bridge before the water fountain show.
The water fountain show starts.
Great rainbow colour fountain show.
This beautiful show last about 20 minutes.
Under Banpo Hangang bridge angle shot.
Water fountain timing:
September - October
* Weekdays: 12:00, 16:00, 20:00, 20:30, 21:00 (20min)
* Weekends: 12:00, 14:00, 16:00, 18:00, 20:00, 20:30, 21:00, 21:30 (20min)
Take the Seoul Metro to the Express Bus Terminal Station (Seoul Subway Line 3,7 or 9), Exit 8-1.
Go straight for 250m, and turn right at the Express Bus Terminal 4-way intersection.
Continue going straight for 400m and cross the road.
Go straight through the underpass to arrive at the park.