1. introduction

In a vision at the conclusion of the book of Daniel, the prophet sees a man standing on the bank of the river asking the man dressed in linen who was above the waters of the river, “How long will it be until the end of these wonders?” In that instance, Daniel’s revelation concerned the end time. However, even prior to Daniel’s eschatological vision, the Bible records a number of miraculous events, many of them associated with water. Predicting how long wonders will continue is beyond the scope of this paper. Rather, this paper will try to quantify the amount of water involved in one of God’s miracles: how much water did God heap up to enable the Children of Israel to cross the Jordan and enter the promised land?

2. Israel Crosses the Jordan

Summary of Passage

As described in Joshua, chapters 3 and 4, the Israelites entered Canaan by crossing the Jordan opposite of Jericho, 20 miles south of Adam during the time of grain harvest. The time of grain harvest would have been during the months of April to May when the runoff from the spring rains and the snowmelt from the mountains would have been at a yearly high.[1] The priests carried the ark and entered the edge of the waters. At this time the waters were cut off and the priests proceeded to dry ground in the center of the Jordan. The waters downstream of the crossing flowed south to the Dead sea, while “the waters flowing down from above stood and rose up in one heap at Adam” (Joshua 3:16). The nation of Israel crossed the river after which 12 men went back into the river where the priests were standing, each selected a stone, and carried it back to the opposite bank. When priests came out and their feet touched the opposite shore, the waters of the Jordan returned.

In order to estimate the volume of water that was piled up at Adam, two major pieces of information are needed: the flow rate of the Jordan during this time of year and the length of time it would take the Israelites to cross the river.

Information Available from the Text

The text must be examined for clues to help approximate the values used to estimate the volume of water heaped up at Adam. Joshua, chapters 3 and 4, provides helpful information regarding i) the flow rate of the Jordan at the time of the stoppage, ii) the number of persons making the crossing, and iii) the procedure for crossing. Considerations for estimating these values are discussed below.

The flow rate of the Jordan river varies throughout the year based on rainfall and snowmelt; therefore, the time of year of the crossing must be determined, if possible. Three separate references indicate that Israel entered Canaan in the spring or when the water was high: “the Jordan overflows all its banks all the days of harvest” (Joshua 3:15), “the waters of the Jordan returned to their place, and went over all its banks as before” (Joshua 4:18); and “the people came up from the Jordan on the tenth of the first month” (Joshua 4:19). Therefore, the value selected for calculating the volume of water piled up at Adam should be within the upper range of possible reasonable values for the flow rate of the Jordan.

The size of the group crossing into Canaan is not specifically stated; however, the passage emphasizes that the entire nation was involved by using such terms as “all the sons of Israel,” “all the nation,” “all Israel,” and “twelve men from the tribes of Israel, one man for each tribe.” Thus, the number of persons crossing the Jordan would have been very large. A rough estimate may be obtained from the census taken by Moses in Numbers, chapter 26, which records a total of 600,000 fighting men over the age of 20 years.

The time taken to cross the river would be directly related to the configuration of the people as they crossed (e.g. single file, ten abreast, en masse). The Bible provides only a vague allusion to this factor. However, a careful reading reveals that, at a minimum, the crossing was intended to be an orderly event, possibly suggesting some sort of linear arrangement. This is attested to in Joshua’s command to maintain a minimum distance from the ark of the covenant of approximately one-half mile[2] in order that they would know the way in which to proceed, because they have not “passed this way before” (Joshua 3:5). Contrary to implications of this verse, some scholars suggest that the necessity for reminding the people to proceed in an orderly fashion arose from the fact that crossing the Jordan was a traditional rite of the Passover. In this view, the reminder from Joshua to follow the ark of the covenant would have been an emendation by the Deuteronomistic historian near the time of Josiah.[3]

3. Estimation of Quantities

Method of Calculation

The volume of water heaped up at Adam has been approximated based on the information available from the biblical text as discussed above and other published data using the following equation:

V = Q_cross * t_cross(Equation 1)

Where: V = volume of water heaped up at Adam, cubic feet

Q_cross = flow rate of river at the time of crossing, cubic feet per minute

t_cross = time for nation of Israel to cross river, minute

Determination of the river flow rate during the spring flood (Q_cross) and the time for the nation of Israel to cross the river (t_cross) are discussed below.

Estimation of Input Parameters

The flow rate of the Jordan river during a normal spring has been estimated based on information regarding a historical flow into the Dead Sea of 4.6E10 cubic feet per year.[4] Given the changes in population and land use during the last 50 years, recent estimates of yearly inflow are much lower and would not reflect the flow rate experienced by Israel. No data were available for the actual spring total; therefore, a value of 50 percent of the total yearly flow was assumed to occur during the four month period of February, March, April, and May (i.e., 0.5 x 4.2E10 = 2.1E10 cubic feet per year). Calculations are also summarized on Table 1. Applying the appropriate conversion factors yields an estimated instantaneous flow rate (Q_cross) of 120,000 cubic feet per minute. Compare this value for the Jordan to a flow rate of approximately 900,000 cubic feet per minute for the West Fork of the San Jacinto River near Humble, Texas, on July 15, 2002, after two days of significant rainfall.[5]

The other input value needed to estimate the volume of water piled up at Adam is the time for the crossing. Little actual information is known for this variable; therefore, several assumptions must be made to derive an estimate for the time of crossing (t_cross). This parameter requires an estimate of the number of persons making the journey, the formation in which they traveled, and an estimate of their speed.

First, the number of persons must be estimated. Say the number of adult males of fighting age represents one-fifth of the population, then the total population would have been 3 million (i.e., 600,000 x 5), not accounting for young ones who might be carried by their parents. Assuming that the children of Israel traversed the dry Jordan in a column of 40 persons abreast with each person 3 feet behind his nearest neighbor, the line of entrants into Jordan would have been 43 miles long [i.e., (3 million x 3)/(40 x 5,280 feet/mile)]. Note that this merely represents the hypothetical formation of 3 million persons as if they were arrayed in a line. Realistically, under the scenario described here, they would have massed at the river’s edge and would have entered the dry riverbed 40 at a time. A reasonable walking rate for people accustomed to desert travel would be 3 miles per hour, especially because the text tells us that “the people hurried and crossed” (Joshua 4:10). This gives a total time for traversing the dry river (t_cross) of 14 hours (i.e., 43 miles/3 miles per hour), just manageable in one day, assuming that the crossing started at daybreak and continued until sunset.

Results

Substituting the estimated values for the river flow rate and the time of crossing into Equation 1 yields a total volume heaped up at Adam of 100 million cubic feet of water (i.e., 120,000 cubic feet per minute x 14 hours x 60 minutes per hour). Thus, the waters of the Jordan River piled up 20 miles north of the crossing to Jericho were approximately equivalent to the volume of two very wet Astrodomes.[6]

A natural explanation for this event would involve an earthquake which could have dislodged a sufficient quantity of the soft limestone rock common in the area to block the Jordan for long enough for the children of Israel to cross the Jordan. Afterwards, the river would quickly have eroded away a new channel to continue to the Dead Sea. During recorded earthquakes in 1267 and 1927, the river was reportedly held back for 16 to 21 hours, respectively,[7] comparable with the time estimated here.

Evaluation of Uncertainty

Each of the values in the calculations described in this paper have been justified on the basis of the biblical account, current available information about the locale, or engineering judgment. Nevertheless, uncertainty remains about the final estimate. Calculations for the base discussed in detail in this paper are provided on Table 1. In addition, the water volume for four alternative cases has also been calculated. The relationship between the variables and the result are linear, so the impact of changing the input values one at a time is relatively uncomplicated. For example, if the actual population was one-tenth the estimated value, the time to cross would take one-tenth as long and the final calculated volume would be one-tenth as large (i.e., 10 million cubic feet). Conversely, walking in a column 20 persons abreast would double the ultimate outcome of the analysis. Regardless of the adjustments made to the input values, the result is a very great quantity of water.

4. Application

Evaluating the quantities involved in God’s miraculous acts helps to make the biblical account more concrete and understandable. The volume of the water held back to permit the Hebrews to cross into Canaan offers a prime example of the way in which Yahweh broke into history to accomplish His sovereign will for Israel. Although natural explanations have been advanced for this miracle, the timing was certainly in God’s hand and used for His ultimate purpose in salvation history.

References

Hertzing, J. “Gulf Coast Salt Domes and Salt Caverns: Storage Caverns” (Encinitas, California: Solution Mining Research Institute), http://www.solutionmining.org/ Introduction%20to%20Solution%20Mining/Salt.htm.

New American Standard Bible. 1999, ed. Kenneth Barker. Grand Rapids: Zondervan Publishing House.

The New Interpreter's Bible: General Articles & Introduction, Commentary, & Reflections for Each Book of the Bible, Including the Apocryphal/Deuterocanonical Books, 12 vols., Nashville: Abingdon Press, c1994-.

Soggin, J.A. 1974. Joshua: A Commentary. Philadelphia: The Westminster Press.

Vengosh, A., E. Farber, U. Shavit, R. Holtzman, M. Segal, I. Gavrieli, T. Bullen, and B. Mayer. 2001. “Tracing the Origin of Salinity of the Jordan River,” in The Proceedings of the 4th International Symposium on Applied Isotope Geochemistry held in Pacific Grove, California, 25-29 June 2001 (US Geological Survey), http://www.rcamnl.wr.usgs. gov/kinwater/vengosh.pdf.

“West Fork San Jacinto River near Humble, Monday July 14, 2002.” National Weather Service: West Gulf River Forecast Service. http://www.srh.noaa.gov/wgrfc/observation/ HMMT2obs.html.

TABLE 1

CALCULATION OF ESTIMATED VOLUME OF WATER PILED UP AT ADAM WHEN

THE CHILDREN OF ISRAEL CROSSED THE JORDAN AND ENTERED CANAAN

No. of

Flow Rate

Average Annual

Spring

Months

During

Total

Width

Length

Time to

Volume

No. of

Case

Flow Rate of Jordan River

Fraction

in Spring

Feb - May

Census

Multiplier

Crossing

of Line

Speed

Cross

of Water

Astrodomes

Description

cubic meters/yr

cubic feet/yr

—

cu ft/min

persons

—

persons

mph

cubic feet

—

Base Case

1.2E+09*

4.2E+10

0.50

1.2.E+05

6.0E+05

3.00E+06

1.04E+08

1.9

0.1 x Census

1.2E+09*

4.2E+10

0.50

1.2.E+05

6.0E+04

3.00E+05

1.04E+07

0.5 x Line

1.2E+09*

4.2E+10

0.50

1.2.E+05

6.0E+05

3.00E+06

2.09E+08

1.5 x Spring

1.2E+09*

4.2E+10

0.75

1.8.E+05

6.0E+05

3.00E+06

1.57E+08

0.66 x Speed

1.2E+09*

4.2E+10

0.50

1.2.E+05

6.0E+05

3.00E+06

1.57E+08

*A. Vengosh et al., "Tracing the origin of Salinity of the Jordan River," in Proceedings of the 4th International Symposium on Applied Isotope Geochemistry

held in Pacific Grove, California, 25-29 June 2001 (US Geological Survey), http://www.rcamnl.wr.usgs.gov/kinwater/vengosh.pdf.

[1] Grain harvest took place in April and May per note on Joshua 3:15. New American Standard Bible, ed. Kenneth Barker (Grand Rapids: Zondervan Publishing House, 1999).

[3] The New Interpreter's Bible: General Articles & Introduction, Commentary, & Reflections for Each Book of the Bible, Including the Apocryphal/Deuterocanonical Books (Nashville: Abingdon Press, c1994-), 3:599.

[4] Corresponding to 1,200 million cubic meters per year. A. Vengosh et al., “Tracing the Origin of Salinity of the Jordan River,” in The Proceedings of the 4th International Symposium on Applied Isotope Geochemistry held in Pacific Grove, California, 25-29 June 2001 (US Geological Survey), http://wwwrcamnl.wr.usgs.gov/kinwater/vengosh.pdf.

[5] “West Fork San Jacinto River near Humble, Monday July 14, 2002,” (National Weather Service: West Gulf River Forecast Service, 2002), http://www.srh.noaa.gov/wgrfc/observation/ HMMT2obs.html.

[6] Assuming a volume for the Houston Astrodome of 10 million barrels. J. Hertzing, “Gulf Coast Salt Domes and Salt Caverns: Storage Caverns” (Encinitas, California: Solution Mining Research Institute), http://www.solutionmining.org/Introduction%20to%20Solution %20Mining/Salt.htm.

[7] J.A. Soggin, Joshua: A Commentary (Philadelphia: The Westminster Press, 1974), 61.

Contents

1. introduction

2. Israel Crosses the Jordan

Summary of Passage

Information Available from the Text

3. Estimation of Quantities

Method of Calculation

Estimation of Input Parameters

Results

Evaluation of Uncertainty

4. Application

References