To apply you will need to provide

College transcripts certifying successful completion of a bachelors degree
Two letters of recommendation from peers mentors or colleagues attesting to your ability to complete graduatelevel coursework and
A personal written statement explaining why you are seeking a graduate certificate in hydrology
GREs are not required

Admission requirements for working professionals and new students
College transcripts certifying successful completion of a bachelors degree
Two letters of recommendation from peers mentors or colleagues attesting to your ability to complete graduatelevel coursework and
A personal written statement explaining why you are seeking a graduate certificate in hydrology
No GREs required

You must have a bachelors degree from an accredited institution in the United States or the equivalent of a four-year degree at an international university that is evaluated by an approved agency Most four-year degrees from accredited non-US institutions are recognized as equivalent but three-year bachelors degree programs from universities in India and some other Asian countries are not.
If you have a non-equivalent three-year degree you will need to complete an additional year of undergraduate study usually 18 to 24 credits at the 300-400 advanced undergraduate level You can complete this work at your home institution at URI or at another accredited institution in the United States.

A cumulative GPA of 3.0 or better in the undergraduate career that can be confirmed with official transcripts from the institution.
TOEFL IBT -
An overall score of 80 or above 82 for teaching assistantship consideration AND
Minimum scores in the following areas -
Reading 19
Writing 18
Listening 17
Speaking 18 the suggested minimum speaking score for a teaching assistantship is 20.
If you are below the minimum in one area by two points or in two areas by one point but have an overall score of 80 or above the Dean will make a determination if you can be considered.
IELTS -
International English Language Testing System IELTS All scores must be sent directly to URI Required minimum score of 6.5 AND minimum scores in the following areas -
Reading 6.5
Writing 6.5
Listening 6.5
Speaking 6.5. The suggested minimum speaking score for a teaching assistantship is 7.
The minimum score on the Paper-based TOEFL is 550.

Pearson Test of English - Required minimum scores are Reading 53 Writing 59 Listening 47 and Speaking 47 - 62 for international teaching assistants.