近年投入溫泉產業研究的專家學者發現：長久以來台灣溫泉區的開發缺乏管制，普遍存在溫泉泉水超抽的現象，致使溫泉水位下降，地表水與淺層地下水補注，因而可能進入溫泉之含水層，造成溫泉水的濃度下降，甚至改變溫泉的成分。泉質的改變是否符合溫泉標準，不僅是溫泉經營業者切身的問題，也是左右消費者再遊意願的因素。本研究調查發現礁溪溫泉區的水質，可分成五大類：雨水、溪水、冷地下水、深熱水（深循環的熱水），以及此四種來源端成分的混合水。調查20 口採樣井，其中5 口為深熱水，導電度最高；2 口為冷地下水，導電度最低；其餘13 口為混合水，導電度依深熱水所佔的比例有所不同。唯深熱水在混合水中所佔的比例越高，導電度越高、溫度也越高、礦物質濃度相對也較高。
以溫泉標準檢核這20 個採樣井，八成（16 口）採樣井的井水符合溫泉標準，其中2 口井採樣井（大忠井及香檳井）雖然溫度大於30℃，但導電度卻低於標準，推測因地理位置鄰近溪流，且地質屬於未拘限含水層，溪水補注與溫泉水混合，故降低了溶解礦物質的濃度。另外2 口採樣井（國小井、二龍井）屬於冷地下水，溫度及導電度都低於溫泉標準。
近幾年礁溪溫泉大量被抽用，溫泉熱水之地下水位有日漸下降的趨勢，使未拘限含水層上方未飽和帶擴大，容納更多的雨水，進而降低溫泉的導電度。工地長時間大量抽水，也使得鄰近的井水導電度明顯降低。 Located at Northeastern Taiwan, the Jiaosi Hot Spring is one of the most favorite recreational destinations in Taiwan. Although the water chemistry of the Jiaosi hot spring had been determined as early in 1975, there are only few researches on its distribution and origins. The typical composition for the Jiaosi hot spring water is mainly by sodium bicarbonate with 50-60 °C of temperature and 900-1200 μS/cm for electric conductivity (EC). I suggest that there are five types of waters representing four end members of origins--rainwater, stream water, cold groundwater, deep hot water and one type of mixing water of those end members. In a total of 20 investigated wells, 5 wells are classified as deep hot water, 2 wells are cold groundwater and 13 wells for mixing water. Because hot spring water had been over-withdrawing in recent years, the water table is continuously declining. The declining water table caused the unsaturated zone expanding and be filled with more infiltrating rainwater that mixing and decreasing the EC values of hot spring waters. A construction site pumped groundwater water for 4 months from July to October 2010 that significantly declined water table to about 2 m lower than the same months of last year. In the period of the pumping, we detected a lower EC values for the hot spring waters.
I suggest that is important for the sustainable use to set a total yield limit of thermal water in the Jiaosi Hot Spring. More researches should be conducted to study the permeability of soil and streambed on top of the unconfined aquifer.
