Denton County approved a culvert policy in 1995 and revised it in 2003 to better control illegal and improperly sized culverts along County roads which often create safety and drainage problems. This policy allows the County to require uniformity and inspection of culverts to maintain proper drainage flows
7.2 Application Procedures:
A. Culvert Permit Application - The Property Owner will complete the culvert permit application and pay the required fee. The property owner may not begin installation of the culvert until the application is approved by the Road and Bridge Precinct and the requirements of Sections7.3 A, and 7.3 B are satisfied. If it is determined a culvert is to be constructed in a Flood Safety Hazard Zone, a Development Permit will also be required. The culvert permit will not be granted until the requirements set forth in the application have been met.
B. Sizing will be conducted by the Road and Bridge Precinct utilizing acceptable engineering practices and taking into consideration the constraints of ROW, extent of downstream grading required, finished floor elevation of proposed residential structures and existing structures, and the overall lay of the land for the best end result.
C. Culvert Permit - Once the requirements of the permit application have been met the Road and Bridge Precinct will issue a Culvert Permit (Exhibit A).
D. Double driveway permits are considered one location. However, both culverts must be completed prior to final acceptance.
7.3 Special Requirements and Conditions
A. The property Owner is responsible for placing a stake to mark the proposed location of the driveway/culvert. After the stake has been set the property owner/contractor is responsible for notifying the Road and Bridge Precinct so the location can be researched so proper sizing of the culvert may proceed. The culverts and/or safety ends are not allowed to cross property lines without a written agreement between both property owners.
B. Within 10 working days of this notification, the assigned Denton County Inspector shall provide the Property Owner with the size and number of culverts to be installed and shall place grade stakes at the culvert location site marking the new culvert centerline and the depth of cut or fill for the flow-line of the culvert ends. It is the responsibility of the Property Owner to insure that his or her contractor install the culvert at those grades. Any culvert not place in accordance with the required grades will be removed and the applicant will be required to re-install it at their own expense.
C. All culverts shall be corrugated steel only (CMP). The length shall in no case be less than 20 feet or more than 60 feet (not inclusive of the length of the safety ends). Driveways for gas well access may use reinforced concrete pipe (RCP).
D. The Owner is required to call 48 hours in advance for inspections during the following stages of the culvert installation process:
After the culvert has been laid at established grade and backfilled to a depth equal to half of the pipe diameter;
After the culvert safety ends (4:1 sloped ends) have been formed and are ready for inspection (reinforcing steel and form work are complete) per the County detail and the remaining backfill has been placed;
Once the culvert and safety ends are complete with all concrete poured and the site cleaned of form work and debris, the Property Owner shall call for a final inspection.
E. Septic Permits will not be issued until the final inspection has been approved by the Road and Bridge Precinct and the Culvert Permit issued.
F. "Temporary" driveway/culverts are not permitted on County Roads without permission being requested in writing and granted by the Road and Bridge Precinct.
7.4 Existing Culverts
Existing Culverts that are in good condition and that do not have any blockages or other restrictions will be allowed to remain in the "as-is" condition. Culverts over 24" in diameter and/or with a flow line depth of 3 feet or more below the edge of pavement will be required to have safety end treatments (SET’s) installed in accordance with the culvert policy section 7.3. If the existing culvert does have safety ends a culvert permit will be issued without changes to the existing culvert.
Replacement of Existing Culverts: Culverts that are to be replaced due to re-grading of bar ditches and road repair issues by County forces will be sized appropriately and installed to an as good or better condition that of the original culvert. If the existing culvert is adequate and undamaged then the culvert can be reused and installed per the new specifications as adopted herein.
7.5 County Enforcement of Policy
A. As stated above in Section 7.3, culverts will not be approved and Septic Permits will not be issued until the final inspection has been approved by the Road and Bridge Precinct and a culvert permit has been issued.
B. If the culvert is not installed within 60 days from the date the application was approved, the application will expire, fees will not be reimbursed, and the property owner must reapply for a culvert permit. A one-time 60 day extension may be granted by the Road and Bridge Precinct when circumstances warrant.
C. Modifications after the permit has been approved and installation accepted will not be permitted and the property owner may be required to remove and replace the driveway/culvert at their own expense.