Fill refers to fill dirt used to elevate a property. Houston regulations on fill don’t take into account that: 1) detention should be added either on-site or nearby to compensate for the effects of fill dirt; 2) the water surface elevations for all the surrounding properties are elevated because water that used to be on the elevated property now runs off. There is no requirement for mitigating fill except in a floodplain where it is required to be mitigated one-for-one; e.g., for every acre-foot elevation an acre-foot of detention must be added. Unfortunately, even in a floodplain, fill can be mitigated by buying compensating detention from a mitigation bank, which may be located where it doesn’t really help like in a different watershed.
In Houston Amendments to the 2012 International Building Codes fill is discussed in several places:
FILL. Deposition of earth materials by artificial means. (Appendix J definitions)
Whenever the surface of a lot or plot is excavated, filled or graded, catch basins or connected underdrains shall be installed to preclude the accumulation of surface water. Surface water shall not be drained onto adjacent property that is not in the same ownership without written permission from the owner of the adjacent property, and existing natural ground drainage of the ground area surrounding the lot or plot that is excavated, filled, or graded shall not be obstructed. No condition shall be created, nor any existing condition maintained, whereby there will be upon any lot or plot excavations, depressions, pits, holes, gullies or other depressions that may accumulate and retain surface water. Any such condition shall be promptly abated and protected by filling in or by providing drainage as set forth above.
E103.2 Exemptions. A grading permit shall not be required for the following:
1. When approved by the building official, grading in an isolated, self-contained area where there is no danger to private or public property.
2. An excavation below finished grade for basements and footings of a building, retaining wall or other structure authorized by a valid building permit. This shall not exempt any fill made with the material from such excavation or exempt any excavation having an unsupported height greater than 5 feet (1524 mm) after the completion of such structure.
3. Cemetery graves.
4. Refuse disposal sites controlled by other regulations.
5. Excavations for wells, tunnels, or utilities.
6. Mining, quarrying, excavating, processing or stockpiling of rock, sand, gravel, aggregate or clay where established and provided for by law, provided such operations do not affect the lateral support or increase the stresses in or pressure upon any adjacent or contiguous property.
7. Exploratory excavations under the direction of soil engineers or engineering geologists.
8. An excavation that: (1) is less than 2 feet (610 mm) in depth or (2) does not create a cut slope greater than 5 feet (1524 mm) in height and steeper than 1 unit vertical in 1½ units horizontal (66.7% slope).
9. A fill less than 1 foot (305 mm) in depth and placed on natural terrain with a slope flatter than 1 unit vertical in 5 units horizontal (20% slope), or less than 3 feet (914 mm) in depth, not intended to support structures, that does not exceed 50 cubic yards (38.3 m³)
on any one lot and does not obstruct a drainage course.
Exemption from the permit requirements of this appendix shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction.
On the Grading Permits for Excavation and Fill Worksheet it states:
SECTION 2: What Type Of Permits And Plans Are Required?
NOTE: When the building official has cause to believe that geologic factors may be involved, grading will be required to conform to
recommended grading, inspection, and testing by a Professional Engineer.
Engineered grading plans are required if “Yes” is answered to question 11. Plans shall be designed, sealed, signed, and dated
by a professional engineer. These grading permits shall be designated as “Engineered Grading”. (5000 cubic yards = 135,000 sq. ft. @ 1 ft depth)
________ (11) Does the grading project exceed 5000 cubic yards?
In other words, if someone desires to elevate their property a foot or less, they may add up to 5000 cubic yards of fill without a permit. That equates to up to 3.1 acre-feet of displaced water with no permit. Even so, driving by almost any development or redevelopment within the area will quickly demonstrate that the preferred method to avoid flooding is the elevation of property. Unfortunately, their newly displaced runoff will raise the water surface elevation for all surrounding properties, possibly causing flooding where there was none and certainly increasing the risk of flooding for lower elevation properties.