What are the duties of County Commissioners when it comes to flooding and floodplains? It is likely you are doing most of those duties already, and you don’t even know it!
When it comes to roads, the duties of a Commissioners Court can be found in and around Chapter 251 of the Texas Transportation Code. To paraphrase, the Commissioner’s role is to supervise the construction and/or maintenance of county roadways. This includes the drainage and floodplains that are associated with those duties.
The term floodplain has different meanings to different people. There are floodplains designated by FEMA (Federal Emergency Management Agency) that are displayed on Flood Insurance Rate Maps (FIRMS). Floodplains are also low-lying areas prone to flooding that may or may not be found on the FEMA FIRMS.
Counties are required to permit FEMA floodplains if they choose to participate in the National Flood Insurance Program (NFIP). In addition, counties are required to maintain floodplains (the low-lying area definition of floodplains) if they are within their right of way (ROW). Counties can and do assist in maintaining floodplains through typical maintenance of their roads and bridges. The illustration below depicts a typical floodplain with various definitions commonly mentioned in FEMA floodplains.
Precincts maintain existing pavements through crack sealing, pothole repairs, slurry seals, seal coats, etc. This is performed when the base is in decent shape; however, in some cases the issue may be the base, or the support structure of the roadway. When preventive measures aren’t sufficient, more significant resources are invested in roadways to restore the pavement AND the base simultaneously. This can be done through a process called full-depth reclamation (FDR), or a traditional pulverization method where lime, cement, or cem-lime is mixed in with the base material, and then a new pavement is placed on top of the rehabilitated base.
Relation to floodplain or flood-related maintenance: Preventive measures including FDR help keep water off of and out of roadways and support the conveyance of water to the ditches, channels, and storm drains.
A word of caution: Be careful when overlaying roadways above existing culverts. In one rare example, as a young professional, I observed an overlay on top of a cross drainage structure. This increased the water surface elevation on a home that was below the roadway! Fortunately, water did not damage the home, but a lesson was learned. We need to be observant of even the most routine maintenance processes that can adversely affect our floodplains or adjacent property owners. Take the opportunity to evaluate and/or update your driveway culverts and/or cross drainage structures. It takes a little planning, but the efforts are well worth the reward in that you can improve drainage and the roadway concurrently. This will make your residents and supervisors very happy!
Another way of maintaining roadways is reviewing the Plans, Specifications, and Estimates (PS&E) of new roadways and/or improvements. This review process by maintenance staff can ensure the roadway is built where it can be maintained with the existing heavy equipment that is available. Reviewing the PS&E also provides the opportunity for newer specifications to be required for roadways that have been changed and/or created over time.
Relation to floodplain or flood-related maintenance: This is a great opportunity to evaluate the capacities, velocities, and headwaters in our storm drain systems.
Maintaining bridges/culverts is equally important when it comes to maintenance. When guardrails are damaged, they must be repaired and done so immediately to afford the traveling public protection to the obstacles behind the guardrails including drop-offs, telephone poles, headwalls, etc.
Monitoring scour under the bridges/culverts due to erosion is also another important maintenance task. Bridge decks must be maintained including debris removal from the deck joints. In rare cases, decks are damaged by traveling vehicles under the roadway, and those repairs may be needed immediately; closure of the bridge is a likely result of that scenario. Abutments must be monitored for separation, buckling, dropping, etc.
Relation to floodplain or flood-related maintenance: Counties can provide safety to the traveling public by cleaning out the channels, re-establishing vegetation and channel slopes, checking for erosion, etc. This also prevents damage to county assets that can ultimately lead to flooding either on the deck of the structures or below in relation to the substructures.
Debris removal (including illegal dumping) is also a necessary maintenance item. Debris reduces the capacity of the creeks, ditches, or channels and can lead to undermining over time, as water always attempts to find the path of least resistance.
Relation to floodplain or flood-related maintenance: Debris removal immediately after rainstorms is a necessary maintenance measure as well as immediate removal of debris that may reduce conveyance and/or may cause environmental complications both within the county ROW and/or downstream.
The Texas Department of Transportation (TxDOT) Bridge Inspection Appraisal Process (BRINSAP) is a system where TxDOT inspects all bridges, typically 20 feet in length or longer as you drive down the roadway, every two years. Although the counties may own and maintain these bridges, TxDOT provides inspections and reports every two years for these types of structures. Counties can utilize this information to prioritize, schedule, and maintain their bridges as they see fit.
Generally speaking, when the inspection indicates the life of the bridge is coming to an end, TxDOT will fund 80 percent to 100 percent of replacement costs including engineering, utility relocation, ROW acquisition, etc., depending on the circumstances.
Following TxDOT’s BRINSAP inspections, bridge-related maintenance may be needed including repair of bridge decks, columns, caps, footings, bents, erosion, etc.
Relation to floodplain or flood-related maintenance: Failure to repair or replace bridges that provide adequate conveyance of water through our drainage systems may increase the risk of flooding in floodplains and/or damage our assets and those of adjacent property owners.
Maintaining rights of way with mowing and/or tree trimming is a common, everyday practice among many agencies. Some choose to utilize herbicides to control growth, but eventually mowing is required.
Relation to floodplain or flood-related maintenance: If mowing/tree trimming is adjacent to a channel, ditch, or river, ensure that the clippings aren’t discharged into the river, which ultimately may lead to reduction in the capacity of the drainage feature when the system is clogged by debris or upstream vegetation.
Review of private utility companies as they expand their services to residents or replace their pipelines, wires, etc., should be done through a permitting process. If it is a new installation, make sure it is placed where you were told it would be placed. If it is a repair or replacement, make sure they put it back the way it was or improve it.
Relation to floodplain or flood-related maintenance: The permitting process provides an opportunity for the governmental agencies to address the question of additional spoils to be removed from ditches and/or floodplains.
Signs should be replaced when the visibility has been reduced or when a sign has been shot, stolen, knocked down, etc. Signs are meant for people who don’t typically travel the area, not for the locals, but they are important.
Relation to floodplain or flooding-related maintenance: This is a great opportunity to install signs related to flood levels or the Texas Floodplain Management Association’s “Turn Around, Don’t Drown” signs to ensure motorists are aware of their surroundings.
Cleaning ditches, culverts, and driveway pipes is very common when it comes to county maintenance. Design and maintenance of side slopes are very important safety aspects of the right of way, as well. Typically speaking, the following is applicable to side slopes:
- 2:1 or steeper – requires guardrail and/or concrete for protection should a motorist run off the roadway and/or to prevent erosion;
- 3:1 – somewhat mowable; should vehicles drive off the roadway they likely won’t flip, but they may need assistance getting out of the ditch;
- 4:1 – recoverable and are mowable but require more ROW; this is typically the best-case scenario for counties, as they are limited with ROW;
- 5:1 – very safe and fully recoverable by motorists; preferred for larger corridors; and
- 6:1 – close to perfection, but even more ROW is needed.
Relation to floodplain or flood-related maintenance: Cleaning storm drain systems is a weekly, if not daily maintenance activity. As we clean/re-establish the flowline of ditches, we should be cognizant and try to improve the side slopes for safety, to prevent erosion, and to reduce the maintenance for our work crews or adjacent property owners next to our roadway ditches.
Dead animals are rarely thought of in urban areas; however, in rural areas of counties, they must be dealt with more often. There are provisions that allow counties to bury dead animals in the ROW; however, most agencies dispose of the animals at the precinct yard for protection of the traveling public and the nuisance they pose.
Relation to floodplain or flood-related maintenance: If animals are buried in the ROW, in a ditch, or in a flood-prone area, ensure any spoils are removed, as this can reduce the capacity of the ditch.
Special assistance projects are rare, but they do occur. Inclement weather including flooding, ice storms, and assistance with major catastrophes can occur.
Relation to floodplain or flood-related maintenance: After the storms pass, sweeping is typically performed. Ensure the sand/salt/various mixtures are not swept into a ditch or storm drain, as that can reduce the capacity of the drainage system.
In addition to inclement weather, county crews may encounter coordination with local law enforcement authorities for excavation of buried vehicles or filming for various movies with Texas as the natural backdrop. These types of activities likely require Traffic Control Plans and should be referenced early on in the coordination efforts.
Relation to floodplain or flood-related maintenance: Ensure spoils are not placed in ditches, channels, or floodplains, as this may reduce the capacity of the storm drain system and/or cause diversion of water.
Maintenance activities are like spinning cogs that are always turning. Even when we’re asleep, something is likely happening that will need to be addressed in the near future, if not immediately. Oftentimes, these maintenance activities are related to potential flooding issues and demonstrate why floodplains matter.