宜蘭雨水豐沛，地底下就是宜蘭的隱形大水庫。當水流動時，帶出了多采的水文故事。
 
湧泉是宜蘭的重要水資源，大洲以西到平原扇頂為湧泉補注區，埤塘主要沿著大洲呈南北向分布。
地表水滲入地層，流入較深的地方受熱，再由裂隙湧至地表即為溫泉。宜蘭多屬碳酸氫鈉泉，以礁溪溫泉最負盛名。
 
 
冷泉中含有二氧化碳，日治時期以蘇澳冷泉製成羊羹和彈珠汽水。泡冷泉是消暑好方法。
 
 
Waterscapes of Lanyang / The Scenic Beauty of Yilan
 
Yilan enjoys plentiful rainfall and is one of the few counties in Taiwan that has no need for reservoirs. Deep beneath Yilan lies a huge unseen reservoir and when the water travels, it spins a colorful yarn about the breathtaking waterscapes of Yilan.
 

Springs are an important water resource for the Yilan plain. The ponds found on the Yilan plain were largely formed from such sources of water. The spring recharge area of the groundwater is located between west of Dazhou and the plain fanhead; areas with an elevation between 7-15 meters are most suited to the formation of groundwater.

The groundwater flows through faults or fissures into deeper areas where it is heated. This creates a pressure difference and causes the water to once again pass through the fissures and move to the surface where it forms hot springs.
Yilan Hot Springs are rich in minerals and are mostly between pH-neutral to weak alkaline with sodium bicarbonate.

Groundwater seeps deep underground through fissures, where it pools and dissolves large amounts of minerals and carbon dioxide (CO2), during the Japanese occupation colonial era, the Su’ao Cold Springs were used to make Yokan (a Japanese-style bean jelly) and Ramune (also known as marble soda). For the local people, taking a dip in the springs was a good way to cool off in the blistering summer heat.