This seal is the original seal of Vista Irrigation District and, we believe, was adopted when the District was created in 1923. The first annual report of the District, for the year 1927, tells us that after the installation of the new water tanks, planting of citrus and avocados increased so rapidly that there was danger of running out of water. This crisis coincided with the building of Henshaw Dam in 1923 by the San Diego County Water Company. Completion of the dam made it possible for the Vista community to receive a reliable source of water, instead of relying on wells in the area.

Considerable time and effort were spent in convincing some reluctant owners of the advantages and advisability of forming a district so that outside water could be obtained. An election was held on August 28, 1923, and 100% of the eligible voters participated. The outcome of the election was 104 votes for and 4 votes against formation of Vista Irrigation District.

The area celebrated the arrival of the first water from Lake Henshaw on February 27, 1926. Following the arrival of water, crops of all kinds were planted in increasing numbers, and the Vista area became known as the "Avocado Capital of the World," with six avocado packing houses in the area.

In June, 1946, after several years of negotiations, Vista Irrigation District purchased the San Diego County Water Company. Included in the purchase was the 43,000 acre Warner Ranch, a former Spanish Land Grant, which includes Henshaw Dam and Lake Henshaw. Purchase of these facilities was purely economic, in that it was a result of a search for cheaper water for the District.

Drought conditions and population growth eventually caused the District to look for other sources of water. On February 16, 1954, The District became a member of the San Diego County Water Authority to take advantage of water imported from the Colorado River and Northern California.

The year 1955 saw a breakthrough in this agricultural community, when the first city-type, mass-built subdivisions were started. The year 1955 also was the beginning of the decline of Vista as an avocado producing and packing center. This was due primarily to the collapse of the price structure (and the drought), which would continue well into the 1960's. Many groves were split into parcels, and the building of homes on these parcels and in subdivisions continued throughout this period.

Today, Vista Irrigation District serves roughly 29,000 accounts, the majority of which are residential, and a population of roughly 131,000. A total of 14,346 acre feet, or over 4.7 billion gallons, of water was distributed and sold within the District in 2022-2023. Of that amount, 72% was distributed for residential use, 12% for industrial and commercial, 11% for landscape irrigation, 4% for agriculture and 1% for governmental use.