NOAA NOS Hurricane Harvey Water Level & Meteorological Data Report 6
on August 29 before curving north and making a second landfall near Cameron, Louisiana at 09:00 GMT
on August 30 with winds of 20 m/s (39 kts). Harvey continued to track northward and became post-
tropical on August 31. Harvey’s slow meandering movement resulted in historic rainfall across eastern
Texas and western Louisiana, including the Houston metropolitan area, causing catastrophic flooding.
Hurricane Harvey resulted in elevated water levels along the Texas and western Louisiana coast
for several days due to storm surge and excessive rainfall runoff as the storm lingered over the region.
Stations farther inland experienced some of the highest water levels as freshwater runoff from rainfall
added to already elevated heights. The peak water level associated with initial landfall was 2.045 m (6.71
ft.) above MHHW, measured at Port Lavaca, Texas at 08/26/2017 08:42 GMT. Other notable peak water
levels near the first landfall were 1.684 m (5.52 ft.) above MHHW at Seadrift, Texas on 08/26/2017 11:24
GMT and 1.628 m (5.34 ft.) above MHHW at Port Aransas, Texas on 08/26/2017 02:12 GMT. Along the
Texas coast through 08/26/2017, peak water levels ranged from 0.311 m to 2.045 m (1.05 ft. to 6.71 ft.)
above MHHW. The lowest peak water level elevations around the time of initial landfall were measured
across southern Texas and western Corpus Christi Bay and the highest peak water level observations were
observed at the entrance to Corpus Christi Bay, Port Aransas, San Antonio Bay and Matagorda Bay.
In the days following initial landfall, some stations continued to experience elevated and in some
cases increasing water levels as heavy flooding rain continued to fall across the region. This was
especially evident in the Houston Ship Channel and within the Intracoastal Waterway east of Galveston
Bay. The highest overall water level observed during Harvey occurred at Manchester, Texas near the Port
of Houston, where water levels reached 3.19 m (10.47 ft.) above MHHW on 8/29/2017 09:54 GMT. The
significant increase in water level was likely caused by runoff through the relatively narrow Houston Ship
Channel. Other notable peak water level observations were 1.263 m (5.07 ft.) above MHHW at High
Island, Texas within the Gulf Intracoastal Waterway and 2.235 m (7.33 ft.) above MHHW on 8/30/2017
14:48 GMT at Lynchburg Landing, Texas (also within the Houston Ship Channel) before this station was
destroyed by the storm. The extended window range through September 3 depicted on water level plots
captures the long duration high water event at several stations, enhanced by excessive rainfall runoff.
Peak water levels from Sabine Pass, Texas to Grand Isle, Louisiana corresponding with the
second landfall ranged from 0.393 to 1.085 m (1.29 to 3.56 ft.) above MHHW. The highest observation of
1.085 m (3.56 ft.) occurred at Lake Charles, Louisiana on 8/30/2017 14:54 GMT and likely included
runoff in addition to storm surge.
The maximum storm surge (residuals) along the Gulf Coast, from Harvey ranged from 0.373 (1.22
ft.) to 3.502 (11.49 ft.). The highest residuals of 3.502 m (11.49 ft.) at Manchester, TX and 2.368 m (7.77
ft.) at Lynchburg Landing, TX were observed in the Houston Ship Channel, which were exacerbated by
excessive rainfall runoff. Other notable storm surge residuals were 2.152 m (7.06 ft.) at Port Lavaca, TX
and 1.758 m (5.77 ft.) at Seadrift, TX. Note that many of the peak residual values occurred within +/- 2
hours of low tide, diminishing inundation in comparison to peak residuals coinciding with high tide (see
Tables 1 & 2).
The highest sustained wind speed recorded at NOS water level stations from southern Texas to
Louisiana during Hurricane Harvey was 49.6 m/s (96.4 kts) at Aransas Pass, TX on 8/26/2017 01:42. The
highest wind gust was also recorded at Aransas Pass, Texas and measured 59.3 m/s (115.3 kts) on
8/26/2017 02:42 GMT. The minimum barometric pressure recorded was 941.8 mb at Rockport, Texas on
8/26/2017 03:36 GMT. Both Port Aransas and Rockport were very near the center (eye) of the storm as it
made landfall and the station at Rockport was destroyed by the storm.
The highest observed current speeds during and following Harvey was 3.93 m/s (7.69 kts),
recorded at Fred Hartmann Bridge within the Galveston Ship Channel, TX on August 29. At this
location, current speeds in the ebb direction (flowing from Houston into Galveston Bay) were several
meters-per-second faster than usual tidal currents. Additionally, the excessive runoff resulted in increased
freshwater inflow into Galveston Bay for over a week. Typically, tidal currents flow from Galveston Bay
towards Houston for several hours daily associated with high tide moving up the estuary. At Rainbow
Bridge, within Sabine River, TX, water flowed into Sabine Lake towards the Gulf of Mexico for over 2
weeks before the typical tidally-driven flow returned.