Water sources in the Angeles National Forest. Ratings: I - Not at all reliable. Water probably only available in early season in wet years or following a significant rain. II - Generally not reliable but will often have water in early season III - Somewhat reliable but best to check before counting on it. May be dry in late season or in droughts. IV - Generally reliable but could go dry in multi-year droughts. V - Reliable all year, typically even in droughts.