Table schema:
CREATE TABLE table_20018310_1 (users___number_ VARCHAR, irrigation_district VARCHAR, juntas_de_regantes__wub_ VARCHAR)

Question: What's the number of users in the Nisibon-Yuma within the Del Este district?
SQL: SELECT users___number_ FROM table_20018310_1 WHERE irrigation_district = "Del Este" AND juntas_de_regantes__wub_ = "Nisibon-Yuma"