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(18) Each layer of fill material applied on a levee must be keyed into the levee section individually in four (4) to six (6) inch layers.
(19) Density tests by a certified soils laboratory will be required to verify compaction of levee fill and trench backfill.
(20) Ditches, power poles, standpipes, distribution boxes, and other above-ground structures located within ten (10) feet of the levee toe must be relocated a minimum distance of ten (10) feet beyond the levee toes.
(21) Pipelines located alongside and within ten (10) feet of the levee toe must be relocated a minimum distance of ten (10) feet beyond the levee toe.
(22) Construction work of any type may not be done on levees or within the floodway during the flood season (see Table 8.1) unless authorized by the General Manager.
(23) The areas adjacent to the levee must drain away from the levee toes for a minimum distance of ten (10) feet.
(24) The finished slope of any project levee construction or reconstruction must be three (3) feet horizontal to one (1) foot vertical, or flatter, on the waterside and two (2) feet horizontal to one (1) foot vertical, or flatter, on the landside of the levee.
(25) The finished slope of any bypass levee must be four (4) feet horizontal to one (1) foot vertical, or flatter, on the waterside and three (3) feet horizontal to one (1) foot vertical, or flatter, on the landside of the levee.
(26) An existing levee section being reconstructed, realigned, or otherwise altered, and having encroachments that are located within the levee that are to be replaced or changed, must have detailed plans of the proposed encroachment changes approved by the board prior to start of construction.
(27) The board may require the modification, as necessary, of existing pipelines within a levee section that is being raised to accomodate a higher design water surface elevation in order to prevent seepage along the pipeline and to prevent backflow through the pipeline during the design event.
(28) A set of "as constructed" drawings of any levee project shall be submitted to the board, the department and the Corps of Engineers upon completion of the project.
(29) Stone revetment may be required on levee slopes where turbulence, flow, or wave action may cause erosion.
(30) Grasses or other approved ground covers may be required on levee slopes.
(31) The minimum crown width of a levee is normally twelve (12) feet on minor streams and twenty (20) feet on major streams. The levee crown width for a levee on a specific stream is defined by the project document and/or operations manual in current use and must be consistent with minimum width requirements of existing levees on the specific stream.
(32) A levee having a crown width of fifteen (15) feet or less must have vehicular turnouts at approximately two thousand-five hundred (2,500) foot intervals if there is no existing access ramp within that distance.
(33) As used in this section, the term "approved risk-based analysis" means an analysis which uses simulation modeling of river discharge versus probability of occurrence, river stage versus river discharge estimates, and river stage versus flood damage estimates and accounts for uncertainty in these functions to determine the performance of a proposed flood control feature.
(A) All levees constructed or reconstructed must have a minimum of three (3) feet of freeboard above the design flood plane, or a crown elevation no lower than designed using an approved risk-based analysis.
(B) Unless designed using an approved risk-based analysis, the design freeboard of a levee to be constructed or reconstructed must be appropriately increased when any of the following conditions exist:
(i) High velocity streamflow.
(ii) Excessive wave action.
(iii) Excessive hydrologic, hydraulic, or geotechnical uncertainty in the levee design parameters.
(C) Unless designed using an approved risk-based analysis, levees within one hundred (100) feet of a bridge, or other structure which may constrict floodflows, must have one (1) foot of additional freeboard.
(b) Unreinforced pavement is not permitted on levee slopes.
(c) Pavement for roadways and similar uses is permitted within ten (10) feet of the levee toe.
(d) Pavement within ten (10) feet of the landside levee toe must have appropriate features that intercept seepage and prevent particle migration.
(e) Levee seepage control facilities (e.g., toe drains and toe ditches) must meet the following requirements:
(1) The seepage control facilities must be designed by a civil engineer.
(2) All studies and calculations relating to design and maintenance of the seepage control facility must be submitted to the board with the permit application.
(3) The appropriate rights-of-way for the seepage control facilities must be included in the levee easements.
(f) See Figure 8.01 for illustrated details, dimensions, and terminology for levees and floodways.
(g) If a proposed project which includes levee improvements would result in substantial residential development within an area that without the levee improvements would be subject to the Federal Emergency Management Agency
regulatory 100-year flood plain constraints, the board may require the permittee to mitigate for any increased average annual flood damage by increasing the level of protection provided by the levee improvement project, up to and including the Standard Project Flood.
Note: Authority cited: Section 8571, Water Code. Reference: Sections 8608, 8609 and 8710, Water Code.
s 121. Erosion Control.
(a) Quarry stone, cobblestone, or their equivalent may be used for erosion control along rivers and streams if the material meets the criteria below. Typical sections delineating methods of placement and dimensions of revetment using rock and sacked concrete are shown in Figures 8.02 and 8.03.
(1) Bedding materials must be placed under the stone protection at locations where the underlying soils require such material for stabilization, considering such factors as tidal fluctuation, wave action, and streamflow velocity.
(2) Cobblestone protection must be placed on prepared slopes of three (3) feet horizontal to one (1) foot vertical or flatter.
(3) Cobblestone protection, having acceptable cobblestone gradations, may be used where streamflow velocities ten (10) feet from the bank do not exceed eight (8) feet per second.
(4) Quarry stone protection must be placed on prepared slopes steeper than three (3) feet horizontal to one (1) foot vertical.
(5) Quarry stone protection, meeting required gradations and sizes, may be used at locations where streamflow velocities ten (10) feet from the bank do not exceed twelve (12) feet per second.
(6) Required gradations of cobblestone and quarry stone are as follows:
Cobblestone Quarry stone
Stone Percent Stone Percent
Size Passing Size Passing
15 " 100 15 " 100
10 " 55 to 95 8 " 80 to 95
8 " 35 to 65 6 " 45 to 80
6 " 10 to 35 4 " 15 to 45
3 " 1 to 5 2 " 0 to 15
(7) Graded cobblestone and quarry stone must be placed in a manner which avoids segregation.
(8) Where streamflow velocities ten (10) feet from the bank exceed twelve (12) feet per second, special cobble or quarry stone gradation is required. Flow retarding structures, such as retards, wing dams, and rock groins may be permitted at these high streamflow velocity sites.
(9) Alternative bank protection materials may be permitted by the board. Possible alternatives include but are not limited to: sacked concrete; broken concrete free of projecting steel; reinforced concrete; precast concrete cribbing; and stone-filled gabion baskets.
(10) Broken concrete used for levee revetment may be no larger than sixteen (16) inches at its maximum dimension.
(11) Asphalt or other petroleum-based products may not be used as fill or as erosion control on a levee section or within a floodway.
(12) The minimum thickness of revetment is eighteen (18) inches perpendicular to the bank or levee slope below the usual water surface and twelve (12) inches above the usual surface.
(13) Revetment must be uniformly placed and properly transitioned into the bank, levee slope or adjacent revetment.
(b) When revetment is proposed by an applicant but not required by the board, the standards relating to revetment bedding, gradation, size, shape and thickness are recommended but not required.
Note: Authority cited: Section 8571, Water Code. Reference: Sections 8608, 8609 and 8710, Water Code.
s 122. Irrigation and Drainage Ditches, Tile Drains, and Septic Systems.
(a) Irrigation ditches, drainage ditches, and similar facilities must satisfy the following criteria:
(1) All ditches must be located at least ten (10) feet from the levee toe.
(2) The bottom of any agricultural ditch must be located above the projected levee slope. Accordingly, a deep ditch may need to be located farther than the minimum ten (10) feet from the levee toe. (See Figure 8.01.)
(b) Tile drains, septic systems, and similar facilities must satisfy the following criteria:
(1) All tile drains, septic tanks, or leach fields must be located at least ten (10) feet from the levee toe.
(2) The bottom of any tile drain, septic tank, or leach field must be located above the projected levee slope.
(3) Positive closure valves may be required on a tile drain pipeline to prevent backflow.
Note: Authority cited: Section 8571, Water Code. Reference: Sections 8608 and 8710, Water Code.
s 123. Pipelines, Conduits, and Utility Lines.
(a) The following definitions apply to this section:
(1) Delta Lowlands. "Delta Lowlands" means those lands within the Sacramento-San Joaquin Delta that are approximately at the five- (5) foot contour and below as shown in Figure 8.04.
(2) Delta Uplands. "Delta Uplands" means those lands within the Sacramento-San Joaquin Delta that are above the five- (5) foot contour as shown in Figure 8.04.
(b) Pipelines, conduits, utility lines, and appurtenant structures must conform to the following criteria:
(1) Pipelines, conduits, utility lines, utility poles, and appurtenant structures may not be installed within the levee section, within ten (10) feet of levee toes, or within the floodway during the flood season unless authorized by the General Manager based on reservoir levels, stream levels, and forecasted weather conditions on a case-by-case basis, pursuant to section 11.
(2) Appurtenant structures such as standpipes, utility poles, distribution boxes, guy wires, and anchors, but not including siphon breakers, are generally not permitted in or below the levee crown, on the levee slopes, or within ten (10) feet of the levee toes. Appurtenant structures may be permitted where they will not interfere with levee maintenance or flood fight activities.
(3) Appropriate, visible markers acceptable to the local maintaining agency may be required to identify the location of buried pipelines, conduits, and utility lines. A siphon breaker or other visible appurtenance may be considered an acceptable marker for the attached buried line. Markers must be made of durable, long lasting, fire-resistant material, and must be maintained by the permittee until the pipeline, conduit or utility line is properly abandoned.
(4) Pipelines, conduits, and utility lines that pose a threat or danger to levee maintenance or flood fight activities, such as high-voltage lines, gas lines, and high pressure fluid lines, must be distinctively labeled to identify the contents.
(5) Buried high-voltage lines of greater than twenty-four (24) volts are required to be protected with schedule 40 PVC conduit, or equivalent.
(6) Overhead electrical and communication lines must have a minimum vertical clearance above the levee crown and access ramps of twenty-one (21) feet for lines carrying 750 volts or less, and twenty-five (25) feet for lines carrying higher voltage.
(7) Fluid- or gas-carrying pipelines installed parallel to a levee must be a minimum distance of ten (10) feet from the levee toe and, where practical, may not encroach into the projected levee slope.
(8) Low-voltage electrical or communication lines of twenty-four (24) volts or less may be installed parallel to a levee and within ten (10) feet of the levee toe when it is demonstrated to be necessary and to not interfere with the integrity of levee, levee maintenance, inspection, or flood fight procedures.
(9) The board may require the applicant to have any pipelines, conduits, utility lines and appurtenant structures designed by a registered civil engineer.
(c) Pipelines, conduits, and utility lines installed within the floodway must conform to the following additional conditions:
(1) Pipelines, conduits, and utility lines installed within the floodway must have a minimum cover of five (5) feet beneath the low-water channel, and a minimum of two (2) feet in the remaining area of the floodway. A greater depth of cover may be required based upon the feasibility of achieving the required cover or local soil stability and channel hydraulics.
(2) Open-trench backfill to cover pipes must be placed in a manner consistent with floodway characteristics such as erosion, deposition, and streamflow velocities. This requirement is generally ensured by using suitable material and compacting to the density of adjacent undisturbed material. Compaction tests by a certified soils laboratory may be required.
(3) In general, any standard material may be used for pipelines or conduits to be installed within the floodway ten (10) feet or more from the levee toe or the projected levee slope.
(4) All debris that accumulates around utility poles and guy wires within the floodway must be completely removed following the flood season and immediately after major accumulations.
(5) Pipelines and conduits which are open to the waterway and which could cause flood damage from uncontrolled backflow during the design flood event shall have a readily accessible positive closure device. A flap gate is not a positive closure device.
(d) Pipelines, conduits, and utility lines installed through a levee must conform to the following additional conditions:
(1) The installation of a fluid- or gas- carrying pipeline in a levee section or within ten (10) feet of the toe parallel to the centerline is not permitted.
(2) Pipelines, conduits, and utility lines must be installed through a levee as nearly at a right angle to the levee centerline as practical.
(3) Buried pipelines, conduits, and utility lines that do not surface near the levee toes must have location markers near both levee toes.
(4) Buried pipelines, conduits, and utility lines that cross the levee at right angles must have a location marker located on the levee slope adjacent to either shoulder.
(5) Buried pipelines, conduits, and utility lines that cross the levee at other than right angles must have location markers on the levee slopes adjacent to each shoulder.
(6) Pipelines carrying gas or fluids under pressure must be confirmed free of leaks during construction by pressure tests, X-ray, or equivalent methods, and must be tested anytime after construction upon request of the board.
(7) Pipelines carrying gas or fluids under pressure must have a readily accessible rapid closure device located within ten (10) feet of the landside levee toe.
(8) Pipelines and conduits open to the waterway must have a readily accessible positive closure device unless it can be demonstrated it is not necessary. A flap gate is not a positive closure device.
(9) The side slopes of trenches excavated for the installation of pipelines, conduit, or utility lines may be no steeper than one (1) foot horizontal to one (1) foot vertical. The following are exceptions to this maximum slope requirement:
(A) For shallow installations above the flood plane, e.g., twelve (12) inches, vertical side slopes may be allowed.
(B) For that portion of the trench above the design freeboard, vertical side slopes may be allowed.
(10) The bottom width of trenches excavated for the installation of a pipeline, conduit, or utility line must be two (2) feet wider than the diameter of the pipeline or conduit, or two (2) times the pipe diameter, whichever is greater.
(11) The minimum cover for pipelines, conduits, and utility lines installed through the levee crown is twenty-four (24) inches. If it becomes necessary to raise a levee crown to provide minimum cover, the longitudinal slope of the crown must be a minimum of ten (10) feet horizontal to one (1) foot vertical. Where twenty-four (24) inches of cover is not practical, a concrete or other engineered cover is required.
(12) The minimum cover for pipelines, conduits, and utility lines installed within the levee slope is twelve (12) inches. Where the installation will not interfere with levee maintenance or flood fight activities, it may not be necessary to bury the line within the levee slopes.
(13) When practical, pipelines, conduits, and utility lines installed within a levee section must be separated from parallel pipelines, conduits, and utility lines by a minimum of twelve (12) inches, or the diameter of the largest pipeline, conduit, or utility line, whichever is larger, to a maximum of thirty-six (36) inches.
(14) When practical, pipelines, conduits, and utility lines must have a minimum vertical spacing of six (6) inches when crossing other pipelines, conduits, or utility lines.
(15) A siphon breaker with a protective housing may be required and must be installed off the levee crown roadway where it will not interfere with levee maintenance.
(16) Electrical and communication lines installed through a levee or within ten (10) feet of a levee toe must be encased in schedule 40 PVC conduit or equivalent. Low-voltage lines (24 volts or less) and fiber optic cable may be allowed without conduit if properly labeled.
(17) A standard reinforced concrete U-wall for levee erosion protection is required at the outlet end of a pipeline or conduit discharging within ten (10) feet of a levee toe. See Figures 8.05 and 8.06 for U-Wall design criteria.
(18) Existing levee erosion protection must be restored by the permittee if it is damaged during the installation of a pipeline, conduit, or utility line.
(19) The permittee must replant or reseed levee slopes to restore sod, grasses or other nonwoody ground covers that are destroyed or damaged during the installation of a pipeline, conduit, or utility line.
(20) Within the levee or within ten (10) feet of levee toes, any excavation for the installation of a pipeline, conduit, or utility line must be backfilled in four (4) to six- (6) inch layers with approved material and compacted to a relative compaction of not less than ninety (90) percent, per ASTM D1557- 91, dated 1991, which is incorporated by reference and above optimum moisture content or ninety-seven (97) percent, per ASTM D698-91, dated 1991, which is incorporated by reference and at or above optimum moisture content. Compaction tests by a certified soils laboratory will be required to verify compaction of backfill within a levee.
(21) Boring a pipeline or conduit through a levee is permitted if the following additional conditions are met:
(A) The invert of the pipeline or conduit must be located at least three (3) feet above the design flood plane.
(B) The pipeline or conduit must be butt-welded. Polyethylene pipes may be used as provided in subdivisions (f)(4)(A), (f)(4)(B), and (f)(4)(C) of this section.
(C) The pipeline or conduit must be installed by the bentonite boring method or equivalent. The bentonite boring method uses an auger followed by a pipe with multiple port openings through which a bentonite slurry is pumped to ensure sealing of any voids resulting from the boring process.
(e) Pipelines, conduits, and utility lines may be installed by the open cut-method through a levee below the design flood plane, or within the levee foundation under the following conditions:
(1) One or more of the following conditions must apply:
(A) The pipeline, conduit, or utility line will be maintained by a public agency with a history of good maintenance based upon annual maintenance or inspection reports.
(B) The levee is designed to withstand a depth of less than six (6) feet of water measured with respect to the elevation of the landside levee toe.
(C) The levee is designed to withstand a depth of less than twelve (12) feet of water measured with respect to the elevation of the landside levee toe and provides flood protection for a rural area, or an area where the board anticipates little future urban development.
(2) Pipelines open to the waterway must be a minimum of thirty (30) inches in diameter, and must have a readily accessible positive closure device installed on the waterward side.
(3) Seepage along pipelines, conduits, and utility lines must be prevented by either of the following methods:
(A) The pipeline, conduit, or utility line is encased in reinforced concrete cast against firm undisturbed earth.
(B) The conduit has reinforced concrete battered walls at an inclination of one (1) foot horizontal to four (4) feet vertical or flatter.
(4) The work must commence and be completed prior to the flood season.
(5) Levees located within the Sacramento-San Joaquin Delta lowlands may only be cut below the design flood plane after appropriate engineering studies are performed and approved.
(f) Pipelines, conduits, and utility lines may be installed under a levee or stream channel by tunneling, jacking, or boring, if the following conditions are met:
(1) The pipeline, conduit, or utility line is at least thirty (30) feet under the levee.
(2) The pipeline, conduit, or utility line is verified to have the required cover. A greater depth of cover may be required based upon the feasibility of achieving the required cover or on local soil stability and channel hydraulics.
(3) If the installation is to be more than fifty (50) feet below the levee and the entire floodway and streambed, the board may waive the requirement for a permit provided a letter of intent is filed with the board prior to commencement of the project.
(4) The portal and outlet of a tunnel, jacking, or boring must be a minimum distance of ten (10) feet beyond the projected levee slope without an approved stability and seepage analysis.
(5) Installation may occur during the flood season and when the water surface elevation in the floodway is expected to be above the elevation of the landside levee toe if adequate containment cells are constructed at the portal and outlet.
(6) The installation of a pipeline, conduit, or utility line under levees in the Sacramento-San Joaquin Delta lowlands requires adequate containment cells at the portal and outlet when the installation is less than fifty (50) feet below the streambed and levee toes.
(7) Pipelines carrying gas or fluids under pressure below a levee must have provision for rapid closure.
(8) Pipelines and conduits open to the waterway and below a levee must have a positive closure device which is accessible at all times unless it is demonstrated to be unnecessary. A flap gate is not a positive closure device.
(g) The following pipe materials are allowed within a levee section when designed to resist all anticipated loading conditions and properly installed:
(1) Galvanized iron pipe is allowed if all joints are threaded. Galvanized iron pipe joints must be corrosion protected with PVC tape or polyethylene tape wrapped to a thickness of thirty (30) mils or equivalent.
(2) Schedule 80 polyvinyl chloride (PVC) pipe is allowed if it is entirely buried, all joints are threaded and the components were continually protected from ultraviolet radiation damage or were newly manufactured.
(3) Polyvinyl chloride (PVC) plastic pipe schedule 40, or better, may be used as a conduit for power or communication cables.
(4) High-density polyethylene pipe may be used for pipeline or conduit installations provided the following conditions are met:
(A) High-density polyethylene pipeline or conduit joints must be heat or electrofusion welded (ASTM Standard F1055-93, dated 1993 or D3261-93, dated 1993 which is incorporated by reference).
(B) High-density polyethylene pipelines and conduits must be designed to resist all anticipated loading conditions, and the design calculations must be submitted to the board.
(C) High-density polyethylene pipelines and conduits must be ultraviolet radiation protected.
(5) Cast-in-place reinforced concrete pipes and box culverts may be used above and below the design flood plane if the concrete is at least six (6) inches thick.
(6) Precast reinforced concrete pipes and box culverts and concrete cylinder pipes may be used above and below the design flood plane if the following conditions are met:
(A) Precast reinforced concrete pipe meets ASTM Specification C76-90, dated 1990 which is incorporated by reference.
(B) Precast reinforced concrete pipe joints and precast box culvert joints are encased in reinforced concrete cast-in-place against firm undisturbed earth.
(C) The cylinders of concrete cylinder pipes are welded and corrosion protected internally and externally.
(D) When installed below the design flood plane, precast reinforced concrete pipe and concrete cylinder pipe must be encased below the springline in concrete cast against undisturbed earth.
(7) Steel pipe may be used for all types of pipeline or conduit installations through a levee above the design flood plane if the pipe meets the following requirements:
(A) The steel pipe is resilient and not materially reduced in quality due to weathering, prior use or other deteriorating conditions.
(B) The steel pipe joints are butt-welded or threaded.
(C) The steel pipe installations are corrosion-proofed externally with a coating of material such as coal-tar enamel, asphalt-dipped wrap, mortar, PVC tape, or polyethylene tape wrapped to a thickness of thirty (30) mils, high solids epoxy, or equivalent.
(D) Unless a continuous internal lining of cement, mortar, or equivalent is provided, as appropriate for the fluid to be conveyed, new steel pipe installations may convey only non- corrosive material, and water is considered corrosive.
(E) Steel pipe installations must be designed to resist all anticipated loading conditions, and the design calculations must be submitted to the board. Steel pipe meeting the following criteria may be used without submittal of design calculations to the board:
(i) Twelve- (12) inches in diameter or less ten- (10) gauge steel pipe.
(ii) Greater than twelve- (12) inches and a maximum of thirty- (30) inches in diameter seven- (7) gauge steel pipe.
(iii) Greater than thirty- (30) inches and a maximum of forty-eight (48) inches in diameter three- (3) gauge steel pipe.
(h) The following materials are not allowed for pipelines or conduits used to carry natural gas or fluids:
(1) Aluminum pipe within a levee section or within ten (10) feet of levee toes.
(2) Cast iron pipe within a levee section or within ten (10) feet of levee toes.
(3) Pipe with flanges, flexible couplings, or other mechanical couplings within a levee section or within ten (10) feet of levee toes.
(4) Prestressed concrete pipe within a levee section or within ten (10) feet of levee toes.
Note: Authority cited: Section 8571, Water Code. Reference: Sections 8608, 8710 and 8712, Water Code.
s 124. Abandoned Pipelines and Conduits.
(a) Abandoned pipelines, conduits, and all appurtenances (such as pumps, standpipes, or positive closure structures) that are located within a levee section, within the projected levee section, or within ten (10) feet of the levee toes shall be completely removed, when practical, and disposed of outside the floodway.
(1) When the invert of an abandoned pipeline or conduit within a levee is above the design flood plane elevation, the pipeline or conduit must be removed.
(2) An abandoned pipeline or conduit located within one (1) foot of the surface of the levee slope shall be removed.
(3) When the invert of an abandoned pipeline or conduit within a levee is six (6) feet or less below the design flood plane elevation, the board may require the removal of the pipeline or conduit.
(4) The side slopes of an excavation to remove an abandoned pipeline or conduit from within a levee must be one (1) foot horizontal to one (1) foot vertical or flatter.
(5) After any pipeline, conduit, or appurtenance is removed from a levee, approved backfill shall be keyed into the levee section with each lift and compacted in four- (4) to six- (6) inch layers with a relative compaction of not less than ninety (90) percent, per ASTM D1557-91, dated 1991, which is incorporated by reference and above optimum moisture content.
(6) Compaction tests by a certified soils laboratory will be required to verify compaction of backfill within a levee or within the projected levee section.
(b) Abandonment of pipelines and conduits within a floodway must be in a manner consistent with the following:
(1) After any pipeline, conduit or appurtenance is removed from a floodway, open-trench backfill must be placed in a manner consistent with the local conditions. Erosive stream reaches will require methods that compact the backfill to at least the density of that of adjacent soils. Compaction tests by a certified soils laboratory may be required to verify compaction within the floodway.
(2) Abandoned pipelines or conduits within the berm and within thirty (30) feet of the top of the streambank must not be filled with concrete but may be removed if exposed by bank erosion.
(c) If it is determined by the board that it is impractical or detrimental to the levee to remove an abandoned pipeline or conduit from a levee section, the pipeline or conduit must be completely filled with concrete.
(1) Concrete to be used to fill an abandoned pipeline or conduit must be a three- (3) sack cement mix, or equivalent, with aggregate having a maximum size of three-eighths (3/8) inch, and a water content sufficient to produce a six-(6) to eight- (8) inch slump.
(2) A detailed plan for filling an abandoned pipeline or conduit with concrete may be required to be submitted for approval by the board prior to start of work.
(3) A pipeline or conduit to be filled with concrete must have a minimum cover of three (3) feet below the waterward levee slope.
(4) See Figure 8.07 for illustrated details on sealing abandoned pipelines and conduits.
(d) Concrete pipes may be plugged with concrete at each end as an alternative to complete filling. The length of each plug shall be a minimum of two (2) feet or twice the diameter of the pipe, whichever is greater.
Note: Authority cited: Section 8571, Water Code. Reference: Sections 8608 and 8710, Water Code.
s 125. Retaining Walls.
(a) Retaining walls within an adopted plan of flood control must comply with the following requirements:
(1) Retaining walls greater than three (3) feet in height must be designed by a licensed civil engineer.
(2) Retaining walls may be of reinforced concrete, concrete gravity section, or of equivalent material and durability.
(3) Retaining walls in the landside levee slope must have appropriate features that intercept seepage and prevent particle migration.
Note: Authority cited: Section 8571, Water Code. Reference: Sections 8606, 8609 and 8710, Water Code.
s 126. Fences and Gates.
(a) Fences within a floodway, on a levee, or near a levee must conform to the following:
(1) Fences, walls, and similar structures are permitted within floodways if they do not obstruct floodflows or cause the accumulation of debris that would obstruct floodflows.
(A) Fences firmly anchored and constructed parallel to the streamflow are normally permitted.
(B) Fences not parallel to the streamflow shall be designed and constructed to not adversely affect stages and velocities.
(2) All fences parallel to a levee must be located a minimum distance of ten (10) feet off the levee toe.
(3) Fences crossing a levee, where permitted, must be installed at a right angle across the levee.
(4) Fences crossing a levee crown must have an opening a minimum of fourteen (14) feet in width or a suitable gate installed on the levee crown.
(5) After January 1, 1998, new fences that are designed to give way during high water events shall not be allowed on the water side of a levee. Fences proposed to be constructed after January 1, 1998 on the water side of a levee that are partially or wholly under water during high water events, and that are located within state maintenance areas within city limits under the jurisdiction of the board, shall be constructed so as to be removable by the permittee in segments during times of high water events as the water level rises up the levee. The permittee shall remove fence segments at its own expense during high water events so that no part of any fence on the water side levee slope is submerged.
(6) Where the distance between fences would be so close as to interfere unreasonably with levee inspection, maintenance and flood fight activities, the board may deny approval for additional fences.
(7) If, in the opinion of the board, a fence becomes unnecessary due to changes in location of public access points or construction of other fences, the permittee must remove the fence at the request of the board.
(b) Gates within a floodway or on a levee must conform to the following:
(1) The gate width on a levee crown must match or exceed the width of the levee crown with a minimum gate width of fourteen (14) feet. A gate width exceeding twenty (20) feet is normally not required. A gate width of twelve (12) feet may be allowed on levees within urban areas if the levee maintenance equipment and any agricultural equipment which must use the gates is less than twelve feet in width.
(2) Cable or chain gates are not permitted across a levee crown or across a levee access ramp.
(3) Gates shall be hinged, and constructed to provide for ease of operation, maximum longevity, and public safety.
(4) Gates may be opened by authorized Department of Water Resources and maintenance personnel and must remain open when required for levee inspections, maintenance, construction, high water patrol, and flood fight activities.
(5) Where the distance between gates would be so close as to unreasonably interfere with levee inspection and maintenance, the board may deny approval for additional gates.
(6) If, in the opinion of the board, a gate becomes unnecessary due to changes in location of public access points or construction of other gates, the permittee must remove the gate at the request of the board.
(7) Keys shall be provided to local the maintaining agency and the Department of Water Resources for all locks on gates providing access to the floodway, levee ramp, levee toe, and along the levee crown.
(c) If the board approves an activity or encroachment that directly or indirectly may result in future unauthorized encroachments (e.g., approving levee modifications associated with a new residential development adjacent to the levee), the board may require the permittee to construct a fence parallel to the levee at a distance of ten (10) feet from the landside levee toe. If a fence is required, it must conform to board standards.
(d) No fence, wall or other barrier may interfere with or preclude legal public access.
Note: Authority cited: Sections 8571 and 8709.3, Water Code. Reference: Sections 8608, 8609, 8709.3 and 8710, Water Code.
s 127. Boating Facilities.
(a) The standards for construction of wharves, piers, docks, boat houses, ramps, and similar boating facilities, are as follows:
(1) Boat ramps may not be cut into the levee section, but may be cut into a berm or placed on a fill.
(2) Boating facilities must be properly anchored to prevent breakaway during floodflows. Acceptable anchoring methods are as follows:
(A) Driven piling must meet the following criteria:
(i) Timber piles must be a minimum of twelve (12) inches in diameter and must be pressure treated.
(ii) The elevation of the top of each pile must be a minimum of two (2) feet above the design flood plane.
(B) Concrete deadmen must meet the following criteria:
(i) The concrete deadman must be of sufficient size to restrain the boating facility and be a minimum of one (1) cubic yard of concrete.
(ii) The concrete deadman must be attached to the floating facility with a steel cable, or equivalent, of sufficient size to restrain the facility.
(3) All appurtenant facilities, including utilities and walkways, installed on or through a levee section to provide service to wharves, piers, or docks, must conform to the appropriate section of the standards.
(b) After each period of high water, all debris caught by a boating facility must be cleared and disposed of outside the limits of the floodway and levee section.
(c) In the event that levee or bank erosion injurious to the adopted plan of flood control occurs at or adjacent to a boating facility, the permittee of the boating facility is responsible for the repair of the eroded area, and for the placement of adequate revetment to prevent further erosion.
(d) Any existing levee revetment or bank revetment damaged during the construction or operation of a boating facility must be restored to its original condition by the permittee of the boating facility.
(e) The levee crown may not be used for parking boat trailers or motor vehicles except where there is adequate crown roadway width to provide twenty (20) feet of unobstructed clearance for two-way vehicular traffic.
(f) Boating materials, equipment or accessories may not be stored on levee slopes.
(g) Floatable boating materials, equipment, or accessories must be securely anchored when stored in the floodway during the flood season.
(h) Boating materials, equipment, or accessories may be stored on the levee crown if storage does not prevent adequate inspection and maintenance of the levee, does not obstruct flood fight procedures, and the following additional requirements are met:
(1) There is adequate levee crown roadway width to provide a minimum of twenty (20) feet of unobstructed clearance for two- way vehicular traffic.
(2) Where a public road or highway is on the levee crown, the design width of the roadway, including the roadway shoulders, must remain clear.
(3) Boating materials, equipment, or accessories may not be stored within fourteen (14) feet of the landward levee shoulder.
(4) Boating materials, equipment or accessories may be stored to within fourteen (14) feet of the waterward leve e shoulder provided the waterward levee slope is revetted to the standards in section 121.
(5) Boating materials, equipment, or accessories may not be stored within thirty (30) feet of the waterward levee shoulder of a levee having an unrevetted waterward slope.
Note: Authority cited: Section 8571, Water Code. Reference: Sections 8608, 8609 and 8710, Water Code.
s 128. Bridges.
(a) The standards for construction or modification of bridges within an adopted plan of flood control are as follows:
(1) Any excavation within the levee section or near bridge supports within the floodway must be backfilled in four- (4) inch to six- (6) inch layers with approved material. The levee section must be compacted to a relative compaction of not less than ninety (90) percent per ASTM D1557-91, dated 1991, which is incorporated by reference and above optimum moisture content. Compaction within the floodway must be to the density of the adjacent undisturbed material.
(2) Compaction tests by a certified soils laboratory may be required to verify compaction.
(3) Bridge piers and bents within the floodway must be constructed parallel to the direction of streamflow.
(4) Bridge piers and bents placed within a floodway to support a widened portion of an existing bridge must be constructed in line with existing bents and piers.
(5) Erosion control may be required on the channel banks or levee slopes upstream and downstream of a proposed bridge.
(6) Drainage from a bridge or highway may not be discharged onto a levee section or streambank.
(7) Plans showing all construction facilities (such as temporary staging, coffer dams, and falsework) which will remain in a floodway during flood season, must be submitted to the board for approval prior to installation of these facilities.
(8) All construction facilities (such as temporary staging, coffer dams, and falsework) must be designed to prevent bank erosion during normal flows and to maintain maximum channel capacity during the flood season.
(9) Stockpiled material, temporary buildings, construction equipment, and detours that obstruct streamflows must be removed from floodways prior to the flood season.
(10)(A) The bottom members (soffit) of a proposed bridge must be at least three (3) feet above the design flood plane. The required clearance may be reduced to two (2) feet on minor streams at sites where significant amounts of stream debris are unlikely.
(B) When an existing bridge being widened does not meet the clearance requirement above the design flood plane, the bottom structural members of the added section may be no lower than the bottom structural members of the existing bridge, except as may be caused by the extension of existing sloped structural members.
(C) When the clearance requirement above design flood plane would result in bridge approach ramp fill in the floodway, the clearance requirement may be reduced to the extent that reasonably balances clearance and fill that would obstruct flow, so as to maintain maximum channel capacity.
(11)(A) Vehicular access from the roadway to the levee crown may be required at each end of a bridge.
(B) Vehicular access from the levee crown to the floodway and/or the landside levee toe beneath the bridge may be required. Ramps may slope upstream as necessary to provide the access required by this subdivision.
(12) Approved gates must be installed at right angles across the levee crown at all points of access to the levee from each end of a bridge.
(13) Any bridge abandoned or being dismantled must be completely removed, and must be disposed of outside the limits of the levee section and floodway.
(14) Pilings, piers, bents, and abutments of bridges being dismantled must be removed to at least one (1) foot below the natural ground line and at least three (3) feet below the bottom of the low water channel.
(15) Any bridge that is damaged to the extent that it may impair the channel or floodway capacity must be repaired or removed prior to the next flood season.
(16) Replacement railroad bridges must have the soffit members no lower than those of the replaced bridge, but are not required to have a specified amount of clearance above the design flood plane.
(17) Bridge replacements and new bridges shall be built at an elevation so that there is no depression in the crown of the levee.
(b) The standards for maintenance of bridges within an adopted plan of flood control are as follows:
(1) The area in and around a bridge site must be kept clear to maintain the design flow capacity.
(2) Trees, brush, sediment, and other debris must be kept cleared from the bridge site and be disposed of outside the limits of the floodway prior to the flood season.
(3) Any accumulation of debris during high flows must be immediately removed from a bridge site and disposed of outside the floodway.
Note: Authority cited: Section 8571, Water Code. Reference: Sections 8608, 8609 and 8710, Water Code.
s 129. Water, Oil, and Gas Wells.
(a) Water wells and any appurtenant structures must be located a minimum distance of ten (10) feet from a levee toe.
(b) Oil wells, gas wells, and any appurtenant structures must be located a minimum distance of thirty-five (35) feet from a levee toe.
(c) Access roads, foundation pads, and stockpiled excavated material within a floodway are normally limited to an elevation of three (3) feet above the natural ground. However, if it is determined by the board that such facilities constructed to the normal elevation would have an adverse effect on the flood-carrying capacity of the floodway, the allowable elevation shall be lower.
(d) Structures and fencing at well sites within the floodway are not permitted without approved hydraulic studies demonstrating that the proposed structure or fence would not impair the floodway.
(e) Permits for water wells require that a survey monument and a permanent bench mark must be installed at the waterside levee toe, as near to the well site as practical, to serve as a vertical control to monitor subsidence.
Note: Authority cited: Section 8571, Water Code. Reference: Sections 8608, 8609 and 8710, Water Code.
s 130. Patrol Roads and Access Ramps.
(a) The following definitions apply to this section:
(1) Access Ramps - "Access Ramps" mean those ramps that provide access to the levee crown from adjacent property and roads.
(2) Patrol Roads - "Patrol Roads" means those roads that provide vehicular access along levee crowns and flood channels for inspection, maintenance, and flood fighting.
(b) Patrol roads must meet the following criteria:
(1) Patrol roads must be surfaced with a minimum of four (4) inches of compacted, class 2 aggregate base (Caltrans Spec. 26-1.02A, July 1992) which is incorporated by reference, or equivalent.
(2) Patrol road surfacing material must be compacted to a relative compaction of not less than ninety (90) percent per ASTM D1557-91, dated 1991, which is incorporated by reference with moisture content sufficient to obtain the required compaction.
(3) Compaction tests by a certified soils laboratory may be required to verify compaction.
(4) Paved patrol roads must meet the design requirements for paved bicycle trails, section 132.
(5) Levee crown surfacing must meet the following additional requirements:
(A) Where the crown width is less than sixteen (16) feet, the minimum surfacing width must be ten (10) feet with a smoothly tapered transition to the edge of the levee shoulder.
(B) Where the crown width is sixteen (16) feet or more, the minimum surfacing width must be twelve (12) feet with a two (2) foot-wide taper at each edge of the surfacing.
(C) The crown roadway must be sloped a minimum of two- (2) percent.
(6) Any patrol road which has been excavated or damaged must be restored to its original condition.
(c) Access ramps are of two common types, head-on or side approach, and must meet the following criteria:
(1) Access ramps must be constructed of approved imported material.
(2) The surfacing for all access ramps must be the same as for patrol roads. Subdivisions (b)(1), (b)(2) and (b)(3) of this section also apply to access ramps.
(3) Any excavation made in a levee section to key the ramp to the levee must be backfilled in four- (4) to six- (6) inch layers with approved material and compacted to a relative compaction of not less than ninety (90) percent per ASTM D1557-91, dated 1991, and above optimum moisture content.
(4) Compaction tests by a certified soils laboratory may be required to verify compaction.
(5) All access ramps must be constructed in such a manner so as to direct all surface drainage away from the levee section.
(6) Approved gates must be installed across access ramps at locations where vehicular access by the public is possible.
(7) Side approach ramps must be used on the waterside levee slope.
(8) Side approach ramps on the waterward slope of the levee must slope downstream.
(9) Typical plans for each type of approach ramp with restrictions and requirements are shown on Figures 8.08 and 8.09.
Note: Authority cited: Section 8571, Water Code. Reference: Sections 8608 and 8710, Water Code.
s 131. Vegetation.
(a) The following definitions apply to this section:
(1) Oversize levee. "Oversize levee" means a levee which encompasses the minimum oversized levee cross-section which has a width of thirty (30) feet at design freeboard elevation and standard levee slopes. (See Figure 8.10.)
(2) Standard size levee. "Standard size levee" means a levee which does not meet the requirements for an oversize levee.
(3) Standard levee slopes. "Standard levee slopes" means the landside levee slope is two (2) horizontal feet to one (1) vertical foot and the waterside levee slope is three (3) horizontal feet to one (1) vertical foot.
(b) Suitable vegetation, if properly maintained, is permitted within an adopted plan of flood control.
(c) Vegetation must not interfere with the integrity of the adopted plan of flood control, or interfere with maintenance, inspection, and flood fight procedures.
(d) With the exception of naturally occurring vegetation which the owner of the underlying land has no responsibility to maintain, any vegetation which interferes with the successful execution, functioning, maintenance or operation of the adopted plan of flood control, must be removed by the owner. If the owner does not remove such vegetation upon request, the board reserves the right to have the vegetation removed at the owner's expense.
(e) Tables 8.3 through 8.6 indicate common types of vegetation considered suitable and unsuitable for planting on levees. Other types of vegetation, not listed in Tables 8.3 through 8.6, may be approved if determined to be similar to listed suitable species or not detrimental to the integrity, operation, or maintenance of the adopted plan of flood control.
(f) Vegetation and vegetation maintenance standards for levees are as follows:
(1) Vegetation is not permitted on the levee crown roadway. Only properly maintained grasses or suitable ground covers are permitted on other portions of the levee crown.
(2) Vegetation growing on levee slopes but infringing onto the levee crown must be trimmed or sprayed to prevent interference with flood fight, maintenance, or inspection activities. (continued)