2.4.14B

CHAP. 2.4 DESIGN DATA REQUIREMENTS

DESIGNS AND ESTIMATES FOR SPECIFICATION PURPOSES (Continued)

CONCRETE AND EARTH DAMS (Continued)

(5) A stratigraphic section showing sequence of formations in the local area
and any helpful correlation with regional stratigraphic sections.

(6) Geologic logs of all drill holes, test pits, trenches, shafts, and tunnels.--
Each geologic log should be a complete compilation of pertinent data
(and interpretations) on the lithology and physical condition on the core;
ground-water levels, as well as water pressure or other permeability
tests; and core recovery data. (During the course of the investigation
drill logs should be forwarded to the Chief Engineer immediately
following the completion of each hole.)

(7) Comments on chemical character of soil and ground water supplemented
by laboratory studies and analyses when necessary.

(8) Photographs illustrating topographic and geologic conditions. --An aerial photograph or mosaic of the dam site and adjacent country is especially helpful and should be included if possible.

(9) As a supplement to the geologic report, a representative suite of samples of the drill core as well as hand samples from rock outcrops and test excavations should be supplied for visual inspection. The samples should be chosen to represent the foundation rocks of poor quality as well as those of average or good quality.

(10) The location of all springs or seeps within or adjacent to the reservoir area and dam site should be indicated on the geologic map. Data on elevation and estimated or measured yield of springs or seeps should also be supplied.

(11) The location of all wells within or adjacent to reservoir area and dam
site should be indicated on the geologic map. Data on elevation of

water surface and, when obtainable, data on yield and drawdown of wells
should be supplied.

(12) The geologic report should include data as to possibilities of seismic
disturbances and probable intensity of quake. This report should also
discuss disposal and waste areas.

Geologic
Report
(Cont.)

Construction

B. A construction materials report. --This should cover an inventory of all feasible sources and should be assembled after exploration and investigations Materials have been completed. It should include subsections relative to all sources Report investigated for:

(1) Embankment materials: pervious, semipervious, and impervious types. Indicate borrow-pit plan of excavation (contemplated) if pertinent.

(2) Concrete aggregates: fine aggregate and coarse aggregate. (See Pages 92 and 93 of Concrete Manual.)

(3) Riprap.

(4) Materials for special purposes, as highway base course, railroad ballast, etc.

(5) Subsections on each type of material reported should include definite information on:

(a) Location and extent of source.

Indicate definite areas on large-scale topographic map and
plot all exploration holes. For maps of earth borrow areas

CHAP. 2.4 DESIGN DATA REQUIREMENTS

DESIGNS AND ESTIMATES FOR SPECIFICATION PURPOSES (Continued)
CONCRETE AND EARTH DAMS (Continued)

fill in topography between borrow areas and the dam site.
Show definite location on a small scale vicinity map which
includes the existing road net, railroads, the dam site, towns,
and rivers.

Include feasible haul routes to site.

Indicate ownership data.

(b) Type of material:

Include description, classification, and characteristics. Emphasize description of jointing, fracturing, bedding, weathering, and other factors influencing fragment size and soundness of riprap and aggregate obtained by quarrying operations.

Include service history of materials if used previously.

(c) Available quantity of material:

Include statement of average thickness, area, and total quantity of suitable material recoverable in each deposit.

Include discussion of all factors which may influence cost and methods of operation. Examples of the factors are presence of ground water, flooding, and extreme cold.

(d) Depth of overburden:

Include description and classification of the material and
feasible methods of removal and disposal of waste.

Include description and amount of clearing and grubbing or
other work necessary to clear the source for stripping and
production operations.

(6) In addition to specific information on each source it is desirable to include a summary of the exploration program. Conclusive statements with recommendations giving the field viewpoint are also desirable. Include photographs of all sources, outcrops, etc. Copies of all the exploration logs should be submitted directly to the Chief Engineer during exploration and a summary of all logs included in the final report. Appro priate representative samples should be submitted from all sources.

The following reservoir data are required (reservoir data required in Subparagraphs 2.4.15C, 2.4.15D, 2.4.15E, 2.4.15H, 2.4.15L, and 2.4.15M are subject to the approval of the Chief, Hydrology Division, Branch of Project Planning, and such approval should be obtained prior to issuing requests for estimates):

A. Reservoir topography.

B. Area-capacity curves or tables.

C. Normal water-surface and dead-storage elevations. Dead-storage elevation
is the absolute minimum reservoir water surface. Since the sill of the
trashrack structure is normally placed at the required dead-storage elevation
no water can be released from the reservoir through the outlet when the
reservoir water surface is at dead-storage level.

RESERVOIR .15
DATA

2.4.15D

CHAP. 2.4 DESIGN DATA REQUIREMENTS

DESIGNS AND ESTIMATES FOR SPECIFICATION PURPOSES (Continued)

CONCRETE AND EARTH DAMS (Continued)

.16

.17

D. Storage capacities required for each use or combination of uses, such as irrigation, flood control, silt control, power, etc.

E. Annual and periodic fluctuations of reservoir storage levels to be shown by
tables or charts summarizing reservoir operation studies for critical
periods.

F. Conditions relative to the trash burden in the stream at flood stage and at
other periods of the year.

G. Probability of full reservoir during winter or spill before ice cover has
melted. Probability of ice formation and thickness to be expected.

H. Effect of silt on life of reservoir.

L Conditions--physical, economical, or political--which would set a definite
limitation on the maximum water-surface elevation (amount of super storage)
permissible. Opinion as to probable cost of dam and related features
normally would not constitute a definite limitation.

J. Cost of right of way versus elevation of maximum water surface above
normal requirements.

K. Appraisal of reservoir right of way including public utilities, pipe lines,
water systems, cemeteries, mining properties, historic monuments, etc.,
including estimated costs for relocation and maintenance of service during
construction.

L. Method of operation for flood control and maximum permissible releases.
M. Reservoir data should contain information concerning suspended sediment
and bed loads of streams entering reservoir.

N. Discussion of fetch and freeboard required.

O. Cost of clearing reservoir basin.

P. Possible damages to private and municipal domestic water and sewage
facilities through added risk to health, safety, or maintenance of a nuisance.
Q Reservoir geology.

RESERVOIR
DATA

(Cont.)

Tail-water curves should be submitted, with supporting data and computations. TAIL-WATER
These curves are of the utmost importance in the design of the spillway and
CURVE
outlet works and are also needed in design of cofferdams and powerhouses. The
curve should preferably be drawn in the field by an engineer experienced in such
works from surveys made especially for the purpose; topography taken for
another purpose is, in general, unsatisfactory. Supporting data should include
an estimate of the value of "n" for use in Kutter's or Manning's formula, which
may vary with stage, and water-surface profiles at known discharges up to the
maximum which it is possible to obtain, and should include at least one at
flood stage. Very rarely will it be possible to obtain profiles for discharges
approaching those used for spillway design; therefore, every effort should be
used to collect all information available on the discharge-elevation relation of
past large floods at as many points as possible.

A hydrograph of the design flood, approved by the Chief, Hydrology Division,
Branch of Project Planning, Denver, Colorado, should be submitted with
recommendations as to conditions to be assumed in determining the required
spillway capacity. A discussion should be included as to whether the spillway

SPILLWAY

2.4.18

OUTLET .18
WORKS

CHAP. 2.4 DESIGN DATA REQUIREMENTS

DESIGNS AND ESTIMATES FOR SPECIFICATION PURPOSES (Continued)
CONCRETE AND EARTH DAMS (Continued)

should be controlled by gates or be uncontrolled; also a discussion of the
possibility of ice jams interfering with operation of gates. In the event of a
possible emergency spillway site, complete data thereon should be forwarded
to the Chief Engineer to enable the designers to make an analysis of such a
design.

Outlet capacities and sill elevation are subject to the approval of the Chief, Hydrology Division, Branch of Project Planning, and such approval should be obtained prior to issuing requests for estimates. The outlet capacity required at various reservoir levels for power, irrigation, flood control, fish, prior rights, etc., with degree of accuracy in regulation should be discussed. The minimum continuous flows required during the winter or nonirrigation seasons should be stated. The hydraulic properties, location, and elevation of any irrigation or power canal diverting from the reservoir should be submitted DIVERSION .19 Hydrographs approved by the Chief, Hydrology Division, Branch of Project DURING Planning, of various frequencies (5-, 10-, 15-, and 25-year floods) should be CONSTRUC- submitted, and the period of the year when high water occurs; actual hydroTION graphs should be included where they are available. Requirement for releases during construction for purposes such as fish, stock water, prior water rights, navigation, etc., should be given; also information concerning the time period during which the streamflow may be cut off completely to permit construction of tunnel plugs or installation of gates.

CLIMATE .20 Severe or unusual climatic conditions that will affect construction procedures or design should be discussed, such as:

ACCESSI- .21
BILITY

A. Precipitation: amount, rate, and distribution by months and total annual.

B. Temperatures: maximum, minimum, and average monthly and mean annual C. Ice conditions: depth, occurrence of frazil and anchor ice; history of ice jams and gorges.

D. Extent of anticipated wave action.

E. Direction, velocity, and duration of high or extreme winds.

F. Length of working season.

The following information on accessibility should be submitted:

A. The average haul from and the name of the nearest railroad or other
shipping terminal for shipped materials such as cement, steel, etc.; the
condition of existing roads during winter and spring, and by what agency
maintained; the requirements for construction of railroad and/or road,
if required; and the possibility of moving material or equipment by waterway
or air transport.

B. Local trucking rates.

C. A description of housing and cther facilities in nearest towns, the requirements for a construction camp, and the need for permanent buildings.

D. Accessibility to other public facilities such as domestic water supply. Possibility of water supply from wells to be dug. Use of streams for domestic sewage.

E. Availability of electric power for construction, including location, voltage, number of phases, and capacity of existing transmission lines; power rate

2.4.21F

CHAP. 2.4 DESIGN DATA REQUIREMENTS

DESIGNS AND ESTIMATES FOR SPECIFICATION PURPOSES (Continued)

CONCRETE AND EARTH DAMS (Continued)

schedules; probability of interruption of supply (especially during extreme
floods) and requirements for additional transmission line. If transmission
lines are to be built by the Bureau, the information listed in Paragraph
2.4.51 should be furnished.

F. Allowable loadings of present highway and highway structures. Widths and
spans of bridges; clearance; type, i. e., concrete, timber, steel. Do any of
the bridges require emergency maintenance? Will any of the bridges be
subject to overtopping by reservoir level?

G. Approximate length of straight approach to the maximum grades.

H. Radius of minimum curves and maximum grades on the highway.

I. Width of highway and amount of superelevations.

.22 Adequate data for each of the following should be furnished:

A. Construction housing, permanent buildings, and ultimate use of housing as
quarters for operators, etc.

B. Roadway on crest of dam: class of road and width.

C. Fishway and recreational facilities: recommendations of local fish
authorities and the Fish and Wildlife Service, and recommendations of the
National Park Service for authorized recreational facilities.

D. Replacement of, or provision for, existing works, including requirements for conveyance of water past dam site to supply downstream rights and needs during construction, closure of the dam, and initial filling of the reservoir.⭑

E. Past and future operations of downstream river control works which affect
the tail water at the dam site.

F. Provision for a power plant or future power development.

G. Navigation works.

H. Provision for raising the crest of the dam at some future date.

I. Photographs of dam site.

J. Survey for roads and other improvements.

K. Timber for structural work and lumber for other uses.

L. For cooling concrete dams, daily maximum, minimum, and mean air and
river water temperatures should be recorded as soon as a weather station
is established. Until that time, river water temperatures should be obtained
whenever possible. Daily readings are preferred although weekly readings
are sufficient to determine the seasonal range of temperatures. The record
should indicate the date, time of day, and corresponding air temperature at
the time the river water temperatures are obtained.

M. Recommended period for construction.

N. Any commitments regarding delivery of water or power.

O. Months of the year in which flow of irrigation ditches or drains to be
crossed can be suspended.

Rel.76 10/24/51

ACCESSI

BILITY (Cont.)

MISCELLANEOUS FEATURES