The population was divided into two major areas within Spain. The first lay within the meridian zone of eastern Andaluz, spreading between the mountain ranges, great plains and salt marshes of Guadalquivir. The second was in the fishing villages and wharves along the northern coastal regions of the country. The populations almost certainly sprang from the same origins, however, as an animal owned by hard-working country people unable to afford specialized breeds, the Spanish Water Dog had to fulfill whatever regional functions were set before it.

In the central regions, the dog was primarily used for hunting foul and small game in the marshes and driving herds of goats, ewes, cows, and pigs to seasonal pastures. In the northern coastal regions, the Spanish Water Dog’s function was much as its Portuguese Water Dog cousin, retrieving fishing tackle and nets and guarding the catch. The northern dogs probably also hunted and performed other functions during the off-season. Caballero (1994) notes this woolly breed was utilized in the mines of the Cuenca Minera del Guadioto (Sierro Morena) to protect mule transports, guard against thieves, and work as rat control in the mines. The dogs’ woolly coat--developed to survive the humid salt marshes--was left long and uncut, thereby providing excellent protection against the excessively hot and humid mines and sun blindness.