Gutierrez Flores de Caballerias. Next to this portal was the House of the Ayuntamiento, a government building for the city. Both of these were behind a small drainage canal that ran east–west. Flooding was always an issue for the plaza and the city in general. The plaza was flooded in 1629 with water two meters deep, ruining many of the merchants located there and requiring many of the portals to be rebuilt. The drainage project to control flooding, known as the desagüe, drafted Indian men over nearly the whole colonial period, to work on this major infrastructure project. Controlling flooding meant health benefits for Mexico City residents by preventing human waste from polluting the city during floods and controlling mosquitoes, which spread disease. It also changed the ecological system that supported birds and fish populations and allowed for Indian cultivation of crops. After the cathedral was constructed in the latter half of the 16th century, the look of the plaza changed. The old church faced east and not to the plaza itself. The new cathedral's three portals towered south over the plaza and giving the area a north–south orientation, which exists to this day. Over much of the 17th century, the plaza became overrun with market stalls. After a mob burned the Viceregal Palace in 1692, depicted in the famous 1696 painting by Cristóbal de Villalpando, authorities attempted to completely clear the plaza to make way for the "Parian", a set of shops set in the southwest corner of the plaza used to warehouse and sell products brought by galleons from Europe and Asia. This was opened in 1703. The Parián is shown at the bottom of Villalpando's painting; it was later destroyed in an 1828 riot. This, however, did not keep the rest of the plaza from becoming filled again with makeshift stalls such as the group known as "San José" located next to the Parian itself. This prompted historian Francisco Sedano to comment that it was ugly and unsightly. He claimed it was very difficult to walk around here at the time because of its uneven pavement, mud in the rainy season, aggressive street dogs, mounds of trash and human excrement tossed among the corn husks and other discarded wrappings. Again the plaza was cleared (with exception of the Parian) by proclamation of Charles IV of Spain in December 1789. Then-viceroy Juan Vicente Güemes Pacheco had the plaza