Potential Water Harvesting for Old Main

Potential Water Harvesting for Old Main

By Mandy Allen

Becca Stevens

Steven Dickert

Reylynne Williams

ABSTRACT

This semester this group concentrated on water harvesting for Old Main on the campus of the University of Arizona. The group calculated that Old Main with one of the surrounding buildings would be capable of harvesting enough water for the turf area around Old Main. One or more of the buildings surrounding Old Main can support the vegetation and grassy area throughout the year. Water harvesting in the southwest should be taken seriously, now that the southwest is in a continued drought.

Prepared for Water Resource for the Tucson Basin, UNVR 195a, Fall 2003

1

Potential Water Harvesting for Old Main

INTRODUCTION

1

For over one hundred years, Old Main has been the primary fixture on campus. There is much to say about Old Main and its history including the fountain that was built to commemorate the twelve students killed in World War 1. Old Main has been renovated numerous times, and there was also a time when it closed because there were no funds for renovations. The project for Old Main now is to renovate and consider possible water harvesting. Old Main is the center of attention for many people that went to the University of Arizona. Many alumni are familiar with Old Main, and many take pride in it by providing funds needed to maintain the beloved building.

Rainwater Harvesting, or collecting rainwater for future water needs, has been used for many centuries as a way to take advantage of seasonal precipitation that otherwise would be lost to runoff or evaporation. People, like the modern Hopi and O`Odham farmers, as well as ranchers in the Southwest United States, construct dams, terraces, ditches, cisterns and ponds to collect and store rainfall for use on their farms and ranches. Rainwater harvesting is a major source of drinking water for many people around the world.

Water harvesting can be applied to Old Main. Old Main has the potential to collect a great amount of water. This water after it collected can be stored around Old Main and used for watering Old Main’s grass and vegetation.

MATERIALS AND METHODS

1

The resources for the project of Old Main came from the University of Arizona Main Library, Science Library, project contact person Grant McCormick, the ground maintenance at the UA, and reports by this class from last year. The library was used as the main resource in finding information about different types of water catchment systems, and water harvesting for landscape and urban developments. Also, a brochure was handed out to the class by Dr. Riley. This brochure is called Rain Store^3, which provides information on how to capture rain water through an underground structure of thin-walled cylindrical columns injection molded of recycled resins of either high impact polypropylene (HIPP), or high density polyethylene (HDPE) plastic for strength, durability, and green industry benefit. [Rain Store^3]. Mr. McCormick is the campus/facility planner for the University of Arizona. Frank Suarez, a classmate, obtained the roof areas of Old main and the surrounding buildings for the class from Mr. McCormick. The group concentrated on buildings near Old Main and in addition to Old Main for potential water harvesting: Forbes Building, Engineering Building, Caesar E. Chavez (Economics) Building, and the Social Sciences Building. The roof areas from these buildings were used to calculate water harvest potentialfor the turf areas and required storage. These were used to develop scenarios for watering around Old Main. To calculate the storage capacity that would be needed, we were provided a table that would do the calculations for us. When the roof area for each building and the turf area of Old Main were inserted, it would give us the amount of the required storage for the rain water. This table includes calculations or amounts of precipitation and evaportranspiration data for Tucson. It gives the total of water harvested for each month from each building. The grounds maintenance provided a list of plants that are in the area of the Old Main. The group used the information that was given to estimate how much water is needed for each plan.

1

RESULTS

Our results indicated that the following buildings would be a good resource for potential water harvesting. The following tables are provided for each of the buildings. We took the roof areas for each of the buildings and divide by four to get the turf area that each of the building could irrigate. The other table shows the expected values just using the turf area of Old Main which is 2,000 sq.ft. This provides the storage capacity that would be needed from each of the buildings to irrigate this turf area.

First of all, table 1 show that Old Main could irrigate 5,510 sq.ft. of turf with a storage capacity of 7,716 cu.ft. This would be likely be enough to irrigate the turf area including all the vegetation around Old Main. It might require additional water from the surrounding buildings to irrigate the 2,000 sq.ft. turf area to the west of Old Main. Instead of using the water harvested from Old Main to irrigate the turf area west of it, the harvested water could be used only to irrigate the vegetation around Old Main.

Table 2 shows that the Social Science Building can easily irrigate 2,000 sq.ft. with storage capacity of 1,368 cu.ft. Table 3 shows that the Caesar E. Chavez (Economics) Building could also easily irrigate the 2,000 sq.ft. of turf with a storage capacity of 2,112 cu.ft. Table 4 shows that the Engineering Building could easily irrigate 2,000 sq.ft. of turf with a storage capacity of 1,402 cu.ft. Table 5 shows that the Forbes Building could irrigate 2,000 sq.ft. with a storage capacity of 1,473 cu ft. The summary of water harvested storage requirements for the buildings, all of which have the potential to harvest sufficient water to irrigate the 2,000 sq.ft. of turf west of Old Main is given in Table 6.

For most of the vegetation surrounding the area of Old Main would require once-twice a week watering. Other require occasional flooding including the grass area. For instance, the Aleppo Pine tree located south of the fountain requires 2500-5000 gallons (334-668 cu.ft) annually. The Kentucy Coffee tree requires occasional flooding while the Sotol requires once a week watering. These are a few that we can identify for the amount of water needed for these plants. The Old Main fountain has a surface are of 772 sq.ft. This could possibly be enough to irrigate the plants surrounding the fountain and perhaps provide some supplemental irrigation to the turf.

DISCUSSIONS

1

The runoff from Old Main can be used for watering the flowers near it and possible around it and the fountain can also provide water for the turf area. One of the surrounding buildingscould be used to provide sufficient harvested water to irrigate the 2,000 sq.ft. of turf to the west of Old Main (see Table 6). A roof catchment system is the most common type of catchment for harvesting rainwater. We can apply a roof gutter around the building which is connected to a storage reservoir. This storage reservoir could be above ground in any shape or form or could be placed underground. Then the reservoir would have a connecting pipe to some sort of faucet or drip irrigation system that would allow water from the reservoir to go through. The Rain Store^3 would be a good idea to use underneath the paved street or underneath the grass turf. The designing of this project is beyond the scope of the project. The Rain Store^3 method is currently being used in Broomfield, Co., Big Fork, MT. and many other places as well. The vegetation around Old Main uses a lot of water throughout the summer seasons, but slows down during the cooler weather. This fluctuation allows time for the water to be harvested during the rainy seasons and this can be used to irrigate during the hot dry summer months. At present, the fountain is drained every two months or when contaminated, into the grassy area. Since we know this, the schedule can be determined when the grass should be watered from the stored water, from the fountain or other buildings.

CONCLUSION

Water harvesting is one of the ongoing projects in the world. Especially in the southwest would water harvesting be of benefit. From the above observations, the University of Arizona would save money by applying water harvesting systems on campus. The buildings stated above may be useful in playing a role for water harvesting. The amounts that each building can capture well cover the turf area of Old Main and could possibly be used for other turf areas near the buildings. With the increase of global temperature and our continuance of drought here in the southwest, we can save groundwater and CAP by using rain water to irrigate the vegetation around Old Main.

REFERENCES

1

1. Gould, J., Nissen-Petersen, E., Rainwater Catchment Systems for Domestic Supply: Design, construction and implementation, Intermediate Technology Publications 1999, 103/105 Southampton, London, WC1B 4HH, UK

2. Johnson, E. A., Harbison, D. G., Landscaping to save water in the desert

3. Matlock, W. G., Water harvesting for urban landscapes: a guide for home owners, small businesses and government agencies in the Tucson area, University of Arizona. Agricultural Engineering Dept. Tucson (Arizona) Water Dept., 1985

4. McCormick, G. Campus Planner, Campus Facilities and Planning, University of Arizona

5. University of Arizona Library,

6. University of Arizona Plant Walk Chart, http: //msg.calsnet.arizona.edu/arboretum/plantwalk/chart.cfm, University of Arizona Facilities Management, Grounds Services

7. Geo Supply, Rain Store^3, http: //

Table 1. Old Main Building roof area, harvested water, turf supportable from harvested water, and storage requirements.

Table 1 / A / B / C / D / E / F / G / H
IRRIGATION
Roof area sq. ft. / 22042 / HARVESTED / REQUIREM. / NET / *
Turf area in sq. ft. / 5510 / ET turf / Precip / Irr. Require. / Storage
sq. ft / on turf / ET-precip / Harv-Irr. / 1598
Cu. Ft from / ET Turf / 5510 / 5510 / for sq.ft. turf
Precip. / 22042 / 5510 / Cu. Ft. / cu.ft.
Month / ft. / cu.ft. / ft. / cu. Ft / cu. Ft. / cu. Ft.
January / 0.09 / 1929 / 0.17 / 955 / 482 / 472 / 1456 / 6005
February / 0.08 / 1837 / 0.21 / 1180 / 459 / 720 / 1116 / 7122
March / 0.07 / 1561 / 0.35 / 1919 / 390 / 1529 / 33 / 7155
April / 0.04 / 790 / 0.47 / 2581 / 197 / 2384 / -1594 / 5561
May / 0.02 / 349 / 0.58 / 3182 / 87 / 3095 / -2746 / 2815
June / 0.02 / 441 / 0.61 / 3388 / 110 / 3278 / -2837 / -22
July / 0.15 / 3251 / 0.53 / 2935 / 813 / 2122 / 1129 / 1129
August / 0.15 / 3233 / 0.47 / 2568 / 808 / 1760 / 1473 / 2602
September / 0.08 / 1745 / 0.42 / 2333 / 436 / 1897 / -152 / 2450
October / 0.07 / 1488 / 0.34 / 1855 / 372 / 1483 / 5 / 2455
November / 0.05 / 1194 / 0.21 / 1157 / 298 / 859 / 335 / 2790
December / 0.09 / 2076 / 0.15 / 836 / 519 / 317 / 1759 / 4549
TOTAL / 0.90 / 19893 / 4.52 / 24887 / 4973 / 19915 / -22
* Storage accumulated per month cannot exceed size of storage tank (given in gray area).
If it does you need to adjust amount of stored water to equal size of storage tank.
A / Precipitation in Tucson in feet
B / Harvested water from roof area that you specify in cubic feet
C / Evapotranspiration of water from a turf area in feet
D / Evapotranspiration of water from your turf area in cubic feet
E / Precipitation in Tucson on turf area you specified in cubic feet
F / Irrigation requirement for your turf area (equals ET minus precipitation) cubic feet
G / Net water accumulated (equals harvested water less the amount used for irrigation) in cubic feet
H / At top of column in gray box is calculated storage requirement in cubic feet
H / In the column is the total amount of water in storage each month in cubic feet

Table 2. Social Science Building roof area, harvested water, turf supported from harvested water, and storage requirement.

Table 2 / A / B / C / D / E / F / G / H
IRRIGATION
Roof area sq. ft. / 26385 / HARVESTED / REQUIREM. / NET / *
Turf area in sq. ft. / 2000 / ET turf / Precip / Irr. Require. / Storage
sq. ft / on turf / ET-precip / Harv-Irr. / 1287
Cu. Ft from / ET Turf / 2000 / 2000 / for sq.ft. turf
Precip. / 26385 / 2000 / Cu. Ft. / cu.ft.
Month / ft. / cu.ft. / ft. / cu. Ft / cu. Ft. / cu. Ft.
January / 0.09 / 2309 / 0.17 / 347 / 175 / 172 / 2137 / 14620
February / 0.08 / 2199 / 0.21 / 428 / 167 / 262 / 1937 / 16557
March / 0.07 / 1869 / 0.35 / 696 / 142 / 555 / 1314 / 17871
April / 0.04 / 945 / 0.47 / 937 / 72 / 865 / 80 / 17952
May / 0.02 / 418 / 0.58 / 1155 / 32 / 1123 / -706 / 17246
June / 0.02 / 528 / 0.61 / 1230 / 40 / 1190 / -662 / 16584
July / 0.15 / 3892 / 0.53 / 1065 / 295 / 770 / 3122 / 3122
August / 0.15 / 3870 / 0.47 / 932 / 293 / 639 / 3231 / 6353
September / 0.08 / 2089 / 0.42 / 847 / 158 / 689 / 1400 / 7753
October / 0.07 / 1781 / 0.34 / 673 / 135 / 538 / 1243 / 8996
November / 0.05 / 1429 / 0.21 / 420 / 108 / 312 / 1118 / 10113
December / 0.09 / 2485 / 0.15 / 303 / 188 / 115 / 2370 / 12483
TOTAL / 0.90 / 23812 / 4.52 / 9034 / 1805 / 7229 / 16584

Table 3. Caesar E. Chavez (Economics) Building roof area, harvested water, turf supported from harvested water, and storage requirement.

Table 3 / A / B / C / D / E / F / G / H
IRRIGATION
Roof area sq. ft. / 14872 / HARVESTED / REQUIREM. / NET / *
Turf area in sq. ft. / 2000 / ET turf / Precip / Irr. Require. / Storage
sq. ft / on turf / ET-precip / Harv-Irr. / 2112
Cu. Ft from / ET Turf / 2000 / 2000 / for sq.ft. turf
Precip. / 14872 / 2000 / Cu. Ft. / cu.ft.
Month / ft. / cu.ft. / ft. / cu. Ft / cu. Ft. / cu. Ft.
January / 0.09 / 1301 / 0.17 / 347 / 175 / 172 / 1130 / 6829
February / 0.08 / 1239 / 0.21 / 428 / 167 / 262 / 978 / 7807
March / 0.07 / 1053 / 0.35 / 696 / 142 / 555 / 499 / 8306
April / 0.04 / 533 / 0.47 / 937 / 72 / 865 / -332 / 7974
May / 0.02 / 235 / 0.58 / 1155 / 32 / 1123 / -888 / 7086
June / 0.02 / 297 / 0.61 / 1230 / 40 / 1190 / -892 / 6193
July / 0.15 / 2194 / 0.53 / 1065 / 295 / 770 / 1423 / 1423
August / 0.15 / 2181 / 0.47 / 932 / 293 / 639 / 1542 / 2966
September / 0.08 / 1177 / 0.42 / 847 / 158 / 689 / 489 / 3455
October / 0.07 / 1004 / 0.34 / 673 / 135 / 538 / 466 / 3920
November / 0.05 / 806 / 0.21 / 420 / 108 / 312 / 494 / 4414
December / 0.09 / 1400 / 0.15 / 303 / 188 / 115 / 1285 / 5700
TOTAL / 0.90 / 13422 / 4.52 / 9034 / 1805 / 7229 / 6193

Table 4. Engineering Building roof area, harvested water, turf supported from harvested water, and storage requirement.

Table 4 / A / B / C / D / E / F / G / H
IRRIGATION
Roof area sq. ft. / 25442 / HARVESTED / REQUIREM. / NET / *
Turf area in sq. ft. / 2000 / ET turf / Precip / Irr. Require. / Storage
sq. ft / on turf / ET-precip / Harv-Irr. / 1355
Cu. Ft from / ET Turf / 2000 / 2000 / for sq.ft. turf
Precip. / 25442 / 2000 / Cu. Ft. / cu.ft.
Month / ft. / cu.ft. / ft. / cu. Ft / cu. Ft. / cu. Ft.
January / 0.09 / 2226 / 0.17 / 347 / 175 / 172 / 2055 / 13982
February / 0.08 / 2120 / 0.21 / 428 / 167 / 262 / 1859 / 15840
March / 0.07 / 1802 / 0.35 / 696 / 142 / 555 / 1247 / 17088
April / 0.04 / 912 / 0.47 / 937 / 72 / 865 / 47 / 17134
May / 0.02 / 403 / 0.58 / 1155 / 32 / 1123 / -721 / 16414
June / 0.02 / 509 / 0.61 / 1230 / 40 / 1190 / -681 / 15733
July / 0.15 / 3753 / 0.53 / 1065 / 295 / 770 / 2983 / 2983
August / 0.15 / 3731 / 0.47 / 932 / 293 / 639 / 3093 / 6075
September / 0.08 / 2014 / 0.42 / 847 / 158 / 689 / 1325 / 7401
October / 0.07 / 1717 / 0.34 / 673 / 135 / 538 / 1179 / 8580
November / 0.05 / 1378 / 0.21 / 420 / 108 / 312 / 1066 / 9646
December / 0.09 / 2396 / 0.15 / 303 / 188 / 115 / 2281 / 11927
TOTAL / 0.90 / 22961 / 4.52 / 9034 / 1805 / 7229 / 15733

1

Table 5. Forbes Building roof area, harvested water, turf supported from harvested water, and storage requirement.

Table 5 / A / B / C / D / E / F / G / H
IRRIGATION
Roof area sq. ft. / 23792 / HARVESTED / REQUIREM. / NET / *
Turf area in sq. ft. / 2000 / ET turf / Precip / Irr. Require. / Storage
sq. ft / on turf / ET-precip / Harv-Irr. / 1473
Cu. Ft from / ET Turf / 2000 / 2000 / for sq.ft. turf
Precip. / 23792 / 2000 / Cu. Ft. / cu.ft.
Month / ft. / cu.ft. / ft. / cu. Ft / cu. Ft. / cu. Ft.
January / 0.09 / 2082 / 0.17 / 347 / 175 / 172 / 1910 / 12865
February / 0.08 / 1983 / 0.21 / 428 / 167 / 262 / 1721 / 14586
March / 0.07 / 1685 / 0.35 / 696 / 142 / 555 / 1130 / 15717
April / 0.04 / 853 / 0.47 / 937 / 72 / 865 / -13 / 15704
May / 0.02 / 377 / 0.58 / 1155 / 32 / 1123 / -747 / 14958
June / 0.02 / 476 / 0.61 / 1230 / 40 / 1190 / -714 / 14244
July / 0.15 / 3509 / 0.53 / 1065 / 295 / 770 / 2739 / 2739
August / 0.15 / 3489 / 0.47 / 932 / 293 / 639 / 2851 / 5590
September / 0.08 / 1884 / 0.42 / 847 / 158 / 689 / 1195 / 6785
October / 0.07 / 1606 / 0.34 / 673 / 135 / 538 / 1068 / 7852
November / 0.05 / 1289 / 0.21 / 420 / 108 / 312 / 977 / 8830
December / 0.09 / 2240 / 0.15 / 303 / 188 / 115 / 2125 / 10955
TOTAL / 0.90 / 21472 / 4.52 / 9034 / 1805 / 7229 / 14244

Table 6. Summary of harvested water from all buildings surrounding Old Main and their storage requirements to irrigate 2,000 sq.ft. of turf west of Old Main.

Buildings / Turf Area
(sq.ft.) / Storage Requirement (cu.ft.)
Social Sciences / 2,000 / 1,368
Engineering / 2,000 / 1,402
Forbes / 2,000 / 1,473
Caesar E. Chavez / 2,000 / 2,112

1