What is the maximum score for ephemeral streams?

The maximum score for ephemeral streams is considered to be less than 19. This aligns with established criteria that categorize ephemeral streams, which are typically characterized by their temporary nature and lack of continuous flow. Because these streams often do not maintain water levels year-round, they tend to score lower in assessments compared to perennial or intermittent streams, which have more consistent water availability.

Such scoring systems take into account factors like the ecological functionality, hydrology, and biodiversity associated with different types of waterways. Since ephemeral streams are usually limited in these aspects, they reflect the lower scoring threshold indicated in the correct answer.

Other ranges, such as 19 to less than 30, 30+, and 15 to less than 25, would not accurately represent the scoring expected for ephemeral streams, as these values suggest a greater ecological stability and functionality than ephemeral streams typically possess.