ARA Water Rights & Irrigation Systems 2 — Questions and Answers
Question 1: Which irrigation method typically achieves the highest water use efficiency for row crops and orchards?
- Flood (surface) irrigation
- Furrow irrigation
- Drip or trickle irrigation (Correct answer)
- Overhead sprinkler systems
Correct answer: Drip or trickle irrigation
Drip irrigation delivers water directly to the root zone with minimal evaporation and runoff, achieving efficiencies of 85–95% compared to 50–70% for flood methods.
Question 2: When appraising irrigated farmland, which factor most significantly influences the contributory value of an irrigation system to the overall property?
- The original installation cost of the equipment
- The age and remaining useful life of the pump and delivery hardware
- The crop yields and income achievable because of the system (Correct answer)
- The manufacturer's brand reputation and warranty period
Correct answer: The crop yields and income achievable because of the system
The contributory value of an irrigation system is best measured by the additional income or yield it enables; systems that support high-value crops with reliable yields command the greatest contributory value.
Question 3: A center pivot irrigation system irrigates land in what geometric pattern, and why does this matter for rural appraisal?
- Square — it maximizes use of rectangular parcels
- Rectangular — it matches standard farm field layouts
- Circular — it leaves corner areas unirrigated, reducing effective acreage (Correct answer)
- Triangular — it is designed for sloped terrain
Correct answer: Circular — it leaves corner areas unirrigated, reducing effective acreage
Center pivots rotate around a fixed point and irrigate a circular area, leaving corner sections of square parcels unirrigated, which appraisers must account for when calculating productive acreage.
Question 4: Which factor is most critical when evaluating the adequacy of an irrigation well for rural appraisal purposes?
- The physical depth of the well casing
- The well's pumping capacity (gallons per minute) and water quality test results (Correct answer)
- The age of the submersible pump motor
- The distance of the wellhead from the nearest property boundary
Correct answer: The well's pumping capacity (gallons per minute) and water quality test results
Pumping capacity determines whether the well can meet crop water demand, and water quality (salinity, minerals) determines suitability for irrigation; both directly affect the property's productivity and value.
Question 5: How does membership in an irrigation district or canal company typically affect rural property value?
- It always decreases value because of mandatory assessment fees
- It has no measurable effect on market value
- It generally increases value by providing a reliable, legally protected water supply (Correct answer)
- It only affects value if the landowner constructed the delivery infrastructure
Correct answer: It generally increases value by providing a reliable, legally protected water supply
Membership in an irrigation district provides access to a reliable, government-backed water supply, which supports crop production and increases the property's marketability and income potential.
Question 6: What type of irrigation delivers water through pipes buried below the soil surface, directly minimizing evaporation losses?
- Solid-set overhead sprinkler system
- Flood or border strip irrigation
- Subsurface drip irrigation (SDI) (Correct answer)
- Wheel-line or hand-line sprinkler system
Correct answer: Subsurface drip irrigation (SDI)
Subsurface drip irrigation buries emitter tubing below the soil surface, delivering water directly to the root zone and virtually eliminating surface evaporation and runoff losses.
Question 7: When comparing two otherwise similar irrigated parcels, one served by gravity-flow canal water and one relying solely on a single irrigation well, which typically commands a higher value and why?
- The well-dependent parcel, because groundwater is always more reliable
- The canal-served parcel, because gravity flow reduces pumping energy costs and diversifies water supply (Correct answer)
- They would have equal value because both provide adequate water
- The well-dependent parcel, because the owner controls the supply independently
Correct answer: The canal-served parcel, because gravity flow reduces pumping energy costs and diversifies water supply
Canal water eliminates electric pumping costs and provides a diversified supply source; dependence on a single well creates risk from aquifer depletion, mechanical failure, and energy price volatility.
ARA Water Rights & Irrigation Systems 2
Which irrigation method typically achieves the highest water use efficiency for row crops and orchards?