An upper level low pressure system remained park across Baja California through October 17.  This feature interacted with plenty of moisture and resulted in periods of very heavy rain from October 15 through the 17.
Widespread flooding developed across the area and many lakes and rivers rose above flood stage and resulted in widespread flooding.  Millions of dollars of damage was done to roads and county infrastructure.
Johnson Fork Creek rose high enough that it caused some water to overflow onto one of the lanes on Interstate 10.  Interstate 10 had to be closed.  The Clear Fork on the Brazos River near Fort Griffin rose to 36.18 feet on October 15; The Llano River at Mason rose to 32.89 foot on October 16; Colorado River near San Saba rose to 32.53 feet on October 17; Colorado River near Ballinger rose to 22.97 feet on October 17; and the San Saba River at San Saba rose to 28.54 inches on October 16.

Flood in SCHLEICHER, TEXAS
From 16-OCT-18 17:02:00 to 16-OCT-18 17:02:00 (CST-6)
Location: EL DORADO MUNI ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

TxDOT reported RR 2596, FM 2129, and County Roads 220, 245, 300, 312, 316, 329, and 350 in Schleicher County closed due to flooding.

Flood in COKE, TEXAS
From 16-OCT-18 18:46:00 to 16-OCT-18 20:46:00 (CST-6)
Location: OAK CREEK RES
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

TxDOT reported FM 3399 closed at the spillway of Oak Creek Reservoir due to flooding.

Flood in BROWN, TEXAS
From 17-OCT-18 10:16:00 to 17-OCT-18 16:15:00 (CST-6)
Location: GROSVENOR
Flood cause: Heavy Rain
Property damage: 2.40M
Crop damage: 0.00K
Reported by: Emergency Manager

Prolonged heavy rainfall flooded roads across Brown County since September and this new flooding damaged some roads and bridges in the county.

Flood in TAYLOR, TEXAS
From 17-OCT-18 14:58:00 to 17-OCT-18 20:45:00 (CST-6)
Location: ABILENE BTTRFLD ARPT
Flood cause: Heavy Rain
Property damage: 394.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Prolonged heavy rainfall flooded roads across Taylor County and this flooding damaged  some roads in the county.

Flood in SUTTON, TEXAS
From 16-OCT-18 19:01:00 to 16-OCT-18 20:31:00 (CST-6)
Location: SONORA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

TxDOT reported Ranch Road 864 and  Ranch Road 189 in Sutton County closed due to flooding.

Flood in KIMBLE, TEXAS
From 17-OCT-18 10:16:00 to 17-OCT-18 16:15:00 (CST-6)
Location: CLEO
Flood cause: Heavy Rain
Property damage: 10.00M
Crop damage: 0.00K
Reported by: Emergency Manager

Prolonged heavy rainfall continued to flood roads across Kimble County.  This flooding damaged 324 miles of roads and several bridges.

Flash Flood in MASON, TEXAS
From 15-OCT-18 22:15:00 to 16-OCT-18 00:15:00 (CST-6)
Location: FREDONIA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported Ranch Road 386 from Mason to Fredonia was closed due to flooding. Also, FM 1871 south of Mason was closed for several miles due to flooded low water crossings.

Flood in CALLAHAN, TEXAS
From 17-OCT-18 14:58:00 to 17-OCT-18 20:45:00 (CST-6)
Location: CLYDE
Flood cause: Heavy Rain
Property damage: 1.06M
Crop damage: 0.00K
Reported by: Emergency Manager

Prolonged heavy rainfall flooded roads across Callahan County and this flooding damaged  some roads and bridges in the county.  This damage and flooding was exasperated by all of the rainfall since September.

Flood in SAN SABA, TEXAS
From 16-OCT-18 18:55:00 to 16-OCT-18 20:55:00 (CST-6)
Location: SAN SABA CO MUNI ARP
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

TxDOT reported that State Highway 16 was closed at the San Saba River bridge due to water over the bridge. The closure was from FM 500 to South Lewis Street.

Flood in MENARD, TEXAS
From 16-OCT-18 19:04:00 to 16-OCT-18 20:04:00 (CST-6)
Location: CALLAN
Flood cause: Heavy Rain
Property damage: 7.10M
Crop damage: 0.00K
Reported by: Department of Highways

TxDOT reported RR 2291, RR 1773, FM 2092, and FM 1311 in Menard County closed due to flooding.  Lots of damage to area roads and county infrastructure form the prolonged flooding.

Flood in MASON, TEXAS
From 17-OCT-18 10:16:00 to 17-OCT-18 16:15:00 (CST-6)
Location: GRIT
Flood cause: Heavy Rain
Property damage: 8.50M
Crop damage: 0.00K
Reported by: Emergency Manager

Prolonged heavy rainfall flooded roads across Mason County and this flooding resulted in damage to 257 miles of road.

Flash Flood in KIMBLE, TEXAS
From 15-OCT-18 22:25:00 to 16-OCT-18 00:25:00 (CST-6)
Location: TELEGRAPH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported several roads closed in Kimble County due to flooded low water crossings, including U.S. Highway 377 from the county line to Junction, Ranch Road 385 from London to Harper,  Ranch Road 479, and FM 2169.

Flash Flood in KIMBLE, TEXAS
From 16-OCT-18 00:28:00 to 16-OCT-18 02:28:00 (CST-6)
Location: SEGOVIA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

The sheriff's office reported Johnson Creek flowing over FM 2169.

Flood in NOLAN, TEXAS
From 17-OCT-18 14:58:00 to 17-OCT-18 20:45:00 (CST-6)
Location: WASTELLA
Flood cause: Heavy Rain
Property damage: 1.10M
Crop damage: 0.00K
Reported by: Emergency Manager

Prolonged heavy rainfall flooded roads across Nolan County and this flooding damaged  some roads and bridges in the county.  This damage and flooding was exasperated by all of the rainfall since September.

Flood in THROCKMORTON, TEXAS
From 17-OCT-18 14:58:00 to 17-OCT-18 20:45:00 (CST-6)
Location: THROCKMORTON
Flood cause: Heavy Rain
Property damage: 400.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Prolonged heavy rainfall flooded roads across Throckmorton County.  This flooding caused damage to some of the roads.

Flood in RUNNELS, TEXAS
From 17-OCT-18 15:30:00 to 17-OCT-18 18:30:00 (CST-6)
Location: BALLINGER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The public posted photos on Facebook of several streets flooded in Ballinger.

Flash Flood in MASON, TEXAS
From 16-OCT-18 03:20:00 to 16-OCT-18 05:20:00 (CST-6)
Location: HEDWIGS HILL
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

The Mason County Sheriff's office reported Beaver Creek flowing onto a road near U.S. Highway 87, 10 miles southeast of Mason. U.S. Highway 87 south of Mason was closed. In addition, Texas Highway 71 in northeastern Mason County was closed due to flooding.

Flash Flood in KIMBLE, TEXAS
From 16-OCT-18 04:20:00 to 16-OCT-18 05:20:00 (CST-6)
Location: SEGOVIA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

The sheriff's office reported that Johnson Fork Creek was flowing over one of the lanes on Interstate 10, with multiple swift water rescues in progress. Interstate 10 was closed as well as FM 2169 north of Interstate 10 due to the Johnson Fork Creek flooding.  First responders launched swift water rescue boats from Interstate 10 and rescued some people from their roofs.

Flood in JONES, TEXAS
From 17-OCT-18 14:58:00 to 17-OCT-18 20:45:00 (CST-6)
Location: RADIUM
Flood cause: Heavy Rain
Property damage: 6.25M
Crop damage: 0.00K
Reported by: Emergency Manager

Prolonged heavy rainfall flooded roads across Jones County and this flooding damaged  some roads in the county.  This damage and flooding was exasperated by all of the rainfall since September.

Flood in HASKELL, TEXAS
From 16-OCT-18 18:50:00 to 16-OCT-18 20:50:00 (CST-6)
Location: ROCHESTER
Flood cause: Heavy Rain
Property damage: 2.30M
Crop damage: 0.00K
Reported by: Department of Highways

TXDOT reported FM 617 between Rochester and Weinert closed due to flooding.  Many other roads were affected across Haskell County.  Prolonged heavy rainfall flooded roads across Haskell County and this flooding damaged some roads in the county.  This damage and flooding was exasperated by all of the rainfall since September.