Thousands of wildlife water developments, commonly known as gallinaceous guzzlers or guzzlers, have been installed throughout the western United States. In general, these units collect runoff from a concrete or other impervious surface and store that water in underground tanks. Water availability is limited to wildlife able to enter a small opening (approx. 20 cm in height) and crawl or walk down a sloped surface to the level of stored water. This design precludes use by large mammals. Moreover, wildlife occasionally may become entrapped in storage tanks, potentially fouling stored water. We developed a method of modifying gallinaceous guzzlers that allows large animals to access stored water and simultaneously decreases the probability of wildlife becoming entrapped in those guzzlers.