Flooding in Texas, August 1 to 20, 2010

River flooding continued into the first third of August based on upstream gaging information in Starr County. Affected communities included Cuevitas, Havana, and the south portions of La Joya and Penitas - locations not protected by the Lower Rio Grande Valley Flood Control Project levee system. The city of Los Ebanos, surrounded on three sides by the river, was most impacted by the flood, which was well over a mile wide for several weeks. Major flooding continued into the first days of August - most likely August 4th.

Voluntary evacuations continued in the area between Cuevitas and Penitas into early August; conditions improved by the 10th as the river returned to its banks. At that point, the cleanup of mud caked mud filled structures and roadways began - these efforts would continue into September.

In all, hundreds of structures, as well as paved and unpaved roads, were damaged significantly by the long duration flood. Most of these were in Los Ebanos, but others were along or south of Military Highway between Cuevitas and the south portion of Penitas. Five homes were evacuated near Military Road in Havana where the river flooded them. Damage to property was estimated to be $[xx] million, with additional [unknown] damage to crops in southwestern Hidalgo County estimated at $ [yy] thousand/million. Note: Damage estimates are included with the July report, based on the direct causative impacts from the deepest, widest, and fastest flows.

River flooding continued into the first third of August across the initial section of the Lower Rio Grande Valley Flood Control Project, which includes improved levees between Penitas and the Anzalduas Diversion Dam southwest of Granjeno. While the levees protected most property behind them, a number of structures built inside the levees suffered significant and costly water damage, from Penitas to south of Granjeno.

The structures included the popular river front Chimney Park RV Resort, which had more than 3 feet of water cover half of the land and property; Pepe's on the River Bar and Grill and the Riverside Club, favorite haunts for Winter Texans and local residents alike which provide river views but unfortunately were covered by feet of mud after the flood waters subsided in August. Some crop may have been destroyed by the flood, but damage was unknown as of this writing in this area. Property damage may have exceeded [$5] million in these areas alone. Note: Damage estimates for this portion of the flood area are listed in the July report.

Flooding of the Lower Rio Grande Valley Flood Control Project floodway/levee system (spillway), which includes the Banker Floodway (from near Granjeno to just south of Pharr), the Main Floodway (from just south of Pharr to the split at the Arroyo Colorado just southwest of Mercedes, the Arroyo Colorado itself, and the North Floodway, (which extends from near Mercedes to near La Villa before curving east to northwest Cameron County), continued through a good portion of August, as water continued to be diverted through Anzalduas for several days beyond the time that water was receding upstream of the dam. Continuing water diversion helps reduce the potential for backwater flooding along the improved levee section (Penitas to Anzalduas) as well as unprotected shorelines west of Penitas. At the same time, the diversion maintained several feet of water in the floodways for days to come which receded more slowly. The floodway emptied out for the most part by August 15th, but local high water hazards continued through at least the 18th.

These floodways, protected by a robust system of levees and gates, protected communities outside of the levees by containing up to 50%, or 4 to 8 to feet of fast flowing water, within them into the first third of August. Unfortunately, a number of residences, dozens of paved and unpaved roads with low water bridges, and some agriculture are located within the floodways; significant damage was noted in several locations. Pumping and plugging operations near Weslaco and La Villa successfully kept high water out of poor drainage locations where the potential for freshwater flooding due to heavy rains would have been exacerbated with periodic thunderstorms, which did not materialize in August. Closed roads included FM 493 and FM 1015, each moderately traveled; at least five homes were flooded along the Main Floodway south of Pharr along I Road; 15 to 20 homes were asked to voluntarily evacuate, and at least two other residences were flooded south of Weslaco near FM 88. Floodwaters also submerged portions of the Llano Grande golf course in Mercedes.

Voluntary evacuations were finally lifted along I Road (Capote Farms subdivision) on August 18th at 6 PM CST, where the 15 to 20 homes mentioned above were located. Wet, muddy conditions continued in these areas until the last week of August; damage assessments began on roadways and bridges impacted in the floodway after the waters finally receded. In all, the floodways contained water for more than 6 weeks.

High flowing water along the river covered a large portion of the Lower Rio Grande Valley National Wildlife Refuge (Santa Ana) south and southeast of Pharr, including a number of unpaved roads. Damage to the roads was unknown at this time; the flooding occurred downstream of the Anzalduas Diversion Dam; river gages downstream at San Benito and Brownsville remained in action stage. Floodwaters did not reach public or private structures, nor roadways, between the Refuge and the Main Floodway. The water finally receded back to muddy pockets sometime between August 27th and 28th.

There was one reported fatality in early August; a man drowned after reportedly driving his vehicle accidentally into the fast flowing waters of the floodway late on August 1st or early on August 2nd. His body was found along the south side of the Main Floodway, near S. Jackson and W. Juan Balli Road just west of Pharr.

Several crops may have been destroyed by the flood along the Main and North Floodways, but damage was unknown as of this writing in this area. Property and infrastructure damage may have exceeded [$10] million in these areas. Note: Dollar damage estimated for the flooding are provided in the July report.

High and fast flowing waters continued through the North Floodway in extreme northwest Cameron County well into August, as water continued to flow through the Anzalduas (Hidalgo County) Diversion Dam into the Lower Rio Grande Flood Control Project (floodways/levee system).

These floodways, protected by a robust system of levees and gates, protected communities outside of the levees by containing up to 50%, or 4 to 8 to feet, of fast flowing water, within them. In Cameron County, there were no reports of structural damage as the North Floodway tracks in largely uninhabited country. However, several paved and unpaved roads were flooded inside the levees, including the Federal Highway 77 (Expressway) frontage road (the Expressway was well above the water level), County Road 506, and FM 1425 (along the Cameron/Hidalgo County line).

The North Floodway finally drained to mud toward the end of the month. The end date of the high water is a best estimate.

Crops may have been destroyed by the flood along North Floodways, but damage in northwest Cameron County was unknown as of this writing. Infrastructure damage to roads and low water bridges may have exceeded [$x] thousand in northwestern Cameron County. Note: The dollar damage estimate is listed with the July report.

High and fast flowing waters continued through the North Floodway in extreme southeastern Willacy County well into August, as water continued to flow through the Anzalduas (Hidalgo County) Diversion Dam into the Lower Rio Grande Flood Control Project (floodways/levee system).

These floodways, protected by a robust system of levees and gates, protected communities outside of the levees by containing up to 50%, or 4 to 8 to feet, of fast flowing water, within them.

The North Floodway finally drained to mud toward the end of the month. The end date of the high water is a best estimate. In Willacy County, there were no reports of structural damage. However, FM 507 and FM 1420, as well as several paved and unpaved county roads, were closed at low water crossings inside the levee. Earlier in July, a leaky levee valve required pumping water away from homes just east of FM 1420 immediately north of the Levee Road near Santa Monica.

Crops may have been destroyed by the flood along North Floodway, but damage in the Willacy County portion was unknown as of this writing. Infrastructure damage to roads and low water bridges may have exceeded [$x] thousand in southeastern Willacy County. Note: The dollar damage for this portion of the flood is included with the July report.