Presentation on theme: "Fort Bend Flood Management Association Flood Risk Reduction Symposium October 3rd, 2014 (Part-A) Brazos River at San Felipe - USGS Gage Fort Bend County."— Presentation transcript:
Fort Bend Flood Management Association Flood Risk Reduction Symposium October 3rd, 2014 (Part-A) Brazos River at San Felipe - USGS Gage Fort Bend County Levee Inspections Using USACE “RIP” Standards Fort Bend County Drainage District
BRAZOS RIVER FACTS: 1,280 Miles Long 45,575 Square Mile Drainage Area 19 Reservoirs 4,000,000+ Acre-Feet of Flood Control Storage
Fort Bend County Drainage District Historical Lower Brazos River Watershed USGS Flood Gages: Waco – Established 1899 Richmond – Established 1922 Hempstead – Established 1939 Highbank – Established 1966 Rosharon – Established 1967 Bryan – Established 1994
Approximately 108 River Miles between Hempstead & Richmond gages. Contributing watershed increases by approximately 800,000 acres. FBCLID No. 20 and Pecan Grove MUD levees are located upstream of Richmond gage. Significant development occurring in northwest Fort Bend County. Previous Brazos River Flooding in Simonton / Valley Lodge Area Dec. 1991 vs Oct. 1994 Peak Elevations (Dec. 91) (Oct. 94) Hempstead: 160.90 159.48 Interstate 10: 113.40 115.50 F.M. 1093: 107.00 107.70 F.M. 1489: 101.40 102.30 Richmond: 77.63 77.10
USGS Brazos River at San Felipe Gage Located on the FM 1458 bridge near Stephen F. Austin State Park. This is the approximate mid-point between the Hempstead and Richmond gages. Installed by USGS field crews in September 2013. 13 field measurements have been taken to date in order to establish a rating curve. Peak flow to date occurred on Nov. 4, 2013 with a measured flowrate of 41,700 cfs. Funded to date by FBCDD, Gulf Coast Water Authority and USGS matching funds.
USGS Brazos River at San Felipe Gage The National Weather Service is planning to establish the San Felipe gage as a River Forecast site and create a website. They will provide 5-day forecasts based on available hydrologic, rainfall, and weather forecast data similar to the current data provided at other Brazos River gages. We are currently evaluating Fort Bend County historic data to establish flood warning stages and associated impacts. We are also working with Austin and Waller County officials to incorporate their potential flood impacts into the River Forecast website.
USGS Brazos River at San Felipe Gage USGS Link: http://waterdata.usgs.gov/tx/nwis/uv?site_no=08111850 www.fortbendcountytx.gov/riverlevels
Fort Bend County Drainage District Fort Bend County Drainage District Levee Inspections using U.S. Army Corps of Engineers “Rehabilitation & Inspection Program” (RIP) Standards 7 Major Categories 1.Initial Eligibility 2.General Items for all Flood Reduction Systems 3.Levee Embankments 4.Floodwalls 5.Interior Drainage System 6.Pump Stations 7.Flood Damage Reduction Channels Each of these major categories is made up of specific inspection components called “Rated Items”. There are a total of 75 “Rated Items” evaluated during our inspections. Grades of “Acceptable”, “Minimally Acceptable” or “Unacceptable” are assigned to each of the 75 items.
Fort Bend County Drainage District Initial Eligibility (12 Rated Items) & General Items for Flood Damage Reduction Segments (3 Rated Items) These items are evaluated before the field inspections through a meeting with the District representatives. (Board Members, Engineer, Operator, Attorney) Updated contact lists, review history including dates of original construction and significant improvements, discuss jurisdictions (MUD’s, city limits, ETJ) Confirmation that the levee design meets current standards. (FEMA 44 CFR 65.10, FBCDCM Sec. 7.0) Evaluate emergency operation procedures and flood preparedness.
Fort Bend County Drainage District Levee Embankments – (15 Rated Items) Grass / Sod Encroachments Unwanted Vegetation Growth Slope Stability Erosion / Bank Caving Settlement Depressions / Rutting Cracking Animal Control Toe Drainage Systems
Fort Bend County Drainage District Floodwalls – (9 Rated Items) Tilting Sliding Settlement Foundations Joints Concrete Surfaces Encroachments Unwanted Vegetation Growth Toe Drainage Systems
Fort Bend County Drainage District Interior Drainage System – (15 Rated Items) Culverts / Discharge Pipes Sluice / Slide / Flap Gates Concrete Surfaces Tilting/Sliding/Settlement or Undermining of Outfall Structures Joints Interior Flood Storage Areas Outfall Channels Trash Racks
Fort Bend County Drainage District Pump Stations – (21 Rated Items) Maintenance, Training & Inspection Records Pumps Generators Primary and Backup Power Sources Fuel System Intake and Discharge Pipes Sluice / Slide / Flap Gates Plant Buildings Communication System Trash Racks
“Interim Policy for Determining Eligibility Status of Flood Risk Management Projects for the Rehabilitation Program Pursuant to Public Law (P.L.) 84-99” U.S. Army Corps of Engineers – March 21, 2014 Section 6.f.3 identifies 20 of the total 75 “Rated Items” that are specifically focused on to determine “Eligibility” for rehabilitation assistance. The levee system is eligible for rehabilitation assistance as long as they do not receive an “Unacceptable” rating on any of these 20 items. Two Separate Ratings are Issued: 1.Eligibility Rating (Eligible or Ineligible) 2. Overall Project Rating (Acceptable, Minimally Acceptable or Unacceptable) Fort Bend County Drainage District
Inspections to Date: FBCLID No. 17 (Telfair) First Colony LID No. 2 FBCLID No. 7 (New Territory) FBCLID No. 20 Preliminary findings are issued to the District with final report issued 6 months later. Attempting to cover as many LID representatives as possible. USACE inspects Fort Bend County levees separately for their official RIP assessment. Fort Bend County Drainage District Levee Inspections using U.S. Army Corps of Engineers “Rehabilitation & Inspection Program (RIP) Standards