Continued rainfall brings flooding to Texoma Herald Democrat Flooding and high-water conditions started rising following overnight storms that continued into Tuesday and are expected throughout the week. The National Weather Service estimated that the majority of Grayson County saw at least one inch of rainfall Tuesday morning with portions of Sherman receiving up to 2.5 inches. Despite this, Denison likely saw the highest rainfall with 2.7 inches of rain by 1 p.m. and the majority of the flooding conditions appear to be centered on Sherman, where multiple streets saw standing water and flooding Tuesday morning. Sherman Police said this heavy rain combined with construction along U.S. Highway 75 and already saturated due to previous storms throughout May. This led to several instances of flooding throughout the corridor.