Lecture A2 - Water Feature Materials Notes

1. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

LECTURE A2 Water Feature Materials My Notes - LHAP 302A Water and Light

• LEARNING OUTCOMES

What I need to be able to do

[ ] Describe selected kinds of ponds [ ] Compare selected pond liners

[ ] Describe selected features employing moving water

[ ] Outline the purpose and selection of equipment used in water feature systems

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2. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

• KINDS OF PONDS
• THE BIG IDEA

Every water feature must be watertight and deep enough to support aquatic life. Once these basic needs are met, features can be built from a broad range of materials.

General pond structure includes

• A defined edge
• A series of shelves or ledges for marginal plants
• A deep area for water lilies
• Optionally, a biofalls waterfall starter and a skimming unit
• EARTH PONDS (Earth Features)

Earth ponds are for sites with good clay subsoil and a natural water feed such as a spring. If space allows for a large earth feature, it can be used for recreational purposes: swimming, canoeing, raising trout in summer, and skating in winter.

• How They Work

Earth ponds do NOT use a commercial liner. They rely on the natural water-holding capabilities of the clay subsoil to reduce water loss through infiltration and percolation. The clay subsoil is puddled to create a natural lining.

What Is Puddling?

Puddling means compacting the clay to completely force the air out of it, leaving a densely packed material that forms a watertight barrier. Historically achieved by herding sheep back and forth over the clay. Today, a vibrating plate tamper can do the work of many sheep in a fraction of the time.

• Key Requirements
• Drainage patterns must be respected for an earth feature to work
• A steady water source is crucial to keep water levels consistent
• Once clay is shaped and puddled, a 4 cm layer of topsoil provides a good start for life
• KEY POINT

Puddled earth ponds require: clay subsoil + steady water source + proper drainage. All three must be present.

• TEST TIP

A puddled earth pond = built on clay subsoil, suitable for large-scale, needs steady water source -> ALL OF THE ABOVE

• FLEXIBLE LINER PONDS

Flexible liners have become the MOST POPULAR material for water feature construction. They offer several key advantages over other pond types.

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3. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

• Advantages
• Liner conforms to virtually any shape - greatest flexibility in design
• Easiest pond material to install
• Minor edge level variations easily corrected after installation
• Top edge finished with variety of materials: pebble beach, indigenous rock, plants
• Relatively easy and inexpensive to repair (challenge is finding the hole!)
• Most economical method of pond construction

Disadvantages / Cautions - Require extra vigilance during installation

• Soil walls can slump due to poor conditions - liner conforms to the slump
• Sharp implements or stones can puncture the liner

The same flexibility that makes liners easy to install makes them vulnerable to sharp objects and unstable soil!

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4. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

FLEXIBLE LINER MATERIALS - The Three Types

Three types of liner material are available, in virtually any size. Many retailers offer small and medium precuts ready to take off the shelf.

• BUTYL RUBBER (Isobutylene with Isopropylene)

A synthetic rubber commonly found in everyday waterproof products like tire inner tubes, caulks, sealants, cling wrap, and even chewing gum.

Key Advantage: Smaller, flat sheets can be WELDED together to create virtually any 3D shape. This process is known as box-welding.

• TEST TIP

Which liner can be welded to create various shapes? -> BUTYL RUBBER. Only butyl can be box-welded; EPDM cannot be welded (seams taped instead).

• PVC (Polyvinyl Chloride)

Made from durable fish-grade PVC. Should contain ultraviolet (UV) stabilizers that help protect the liner from breaking down in sunlight.

Even with UV protection, PVC deteriorates within 2-3 YEARS when exposed to direct sunlight!

You can extend PVC life by covering the liner above water level.

• EPDM (Ethylene Propylene Diene Monomer)

EPDM pond liners have become the MOST POPULAR CHOICE among pond builders.

• Key Characteristics
• Come as flat sheets - folds/pleats when conforming to 3D shapes (hide with plants/rocks)
• Cannot be welded like butyl - seams taped with heavy-duty butyl tape (not always successful)
• Best practice: buy a SINGLE PIECE large enough for the entire pond - no seams
• Even better: design the pond to fit available sizes so no seaming required
• Available in many different sizes and shapes
• Prairie Climate Advantage

EPDM is made from synthetic compounds that keep the material flexible to -70 degrees Celsius even years after installation. This makes it ideally suited to our harsh prairie climate.

Warranty: Most EPDM liners come with a limited 20-year warranty.

CRITICAL: Do NOT use EPDM designed for ROOFING - you must use "fish safe" pond liners!

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5. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

• KEY POINT

EPDM = longest life span in prairie climate. Flexible to -70C, 20-year warranty, most popular liner choice among pond builders.

• PREFORMED (MOULDED) PONDS

A good choice for small urban landscapes. They are durable and can be repaired if punctured. The excavation can be completed in a few hours without large power equipment.

• Materials & Shapes

Manufactured from polyethylene or fiberglass. Available in various shapes:

• Setting Available Shapes

Informal Free-form, kidney shapes (with shelf for marginal plants)

• Formal Rectangular, octagonal, circular, or L-shapes

Prairie Climate Performance Material Life Expectancy Prairie Suitability

Polyethylene 20 years Stands up better in prairie climate

Fiberglass 15-20 years More brittle, freeze/thaw damage

Both are relatively durable and resistant to damaging effects of UV light.

SIZE DECEPTION: Preformed ponds look large in store displays but SHRINK once installed!

If too small, consider installing two ponds connected by a stream. Most manufacturers sell preformed waterfall units to complement their ponds.

• CONCRETE PONDS

The use of concrete for pond construction has RAPIDLY DECLINED with the advent of durable, flexible synthetic materials.

• Disadvantages
• Requires professional concrete contractor - increases cost
• Difficult to create natural shapes - formal designs only
• Very rigid once set - will NOT flex like other linings
• Prone to damage from freeze/thaw cycles
• Once cracked, difficult to return to watertight state
• Must be treated, repeatedly filled and drained to cure (leach chemicals)
• Lime creates additional work during the curing process
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6. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

• Curing the Pond

If adding fish. curing is a necessity. Involves repeatedly filling and draining to leach damaging chemicals. Many methods exist - research the one best for your conditions.

• KEY POINT

Concrete is NOT ideal for prairies: freeze/thaw cracks it, rigid, expensive, needs professional installation and curing.

Summary of Pond Characteristics (Table 1 from Lecture)

• Liners

Type Cost Durability Ease of Install Design Flex Ease of Repair Other

Polyethylene Low Poor Easy Good Difficult Short life span

PVC Low-Med Fair-Good Easy Good If not brittle Punctured; holes hard to find

Butyl/EPDM Med-High High Easy Excellent Possible always Holes hard to find

• Preformed

Type Cost Durability Ease of Install Design Flex Ease of Repair Other

Preformed High Fair Can be difficult Limited Possible Expensive for water qty

• Concrete

Type Cost Durability Ease of Install Design Flex Ease of Repair Other

• Concrete Very High Poor

(freeze/thaw) Need professional Good Hard to keep watertight

• Lime = extra work TEST TIP

Polyethylene appears as BOTH a liner (poor durability, short life) AND a preformed pond material (20-yr life). As a liner it has the WORST durability and shortest life span.

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7. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

• FEATURES WITH MOVING WATER

Incorporating moving water adds both aesthetic and practical benefits. Depending on volume and speed, movement creates a sense of calm or excitement. Fountains, waterfalls, and streams help to AERATE the water.

• Style Matching Is Essential

Moving water tends to dominate the garden, so designs must be complementary:

• Style Appropriate Element Why

Formal Fountains Fountains dont occur in nature (except geysers)

Formal Streams with sharp angles Architectural feel for formal settings

Informal Streams with natural shapes Mimic the irregular lines of nature

Informal NOT fountains Fountains look out of place in informal features

• KEY POINT

Fountains = FORMAL only. They do not occur in nature. Never use in informal features.

• Waterfalls and Streams

Must be carefully planned and constructed to prevent spillage/leaking, reduce evaporation, and create ideal conditions for aquatic plants.

• Evaporation Challenge

Moving water over numerous rocks is subject to HIGH RATES OF EVAPORATION. Keeping streams in scale with the overall installation helps reduce constant topping up.

• TEST TIP

Main challenge with waterfall/stream installations = water loss from evaporation -> TRUE

Water Lilies and Moving Water Water lilies thrive in STILL water. If you want lilies:

• Adjust waterfall volume to reduce velocity entering the main pond
• Consider a large, separate basin just above the main pond level
• Position fountains/streams well away from still-water plants
• Construction Options

Preformed Units: Made from same synthetics as preformed ponds. Engineering done for you. Drawbacks: expensive, limited styles, artificial appearance.

Flexible Liner (Butyl/EPDM): Very durable, greatest opportunity for informal designs. Require thoughtful planning to avoid spillage/leakage. Ideal: series of small pools with cascading water.

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8. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

• Stream Design Challenges
• A stream at the top of a berm looks unnatural - connect ponds through gradual meanders
• Pond sizes, stream capacity, and pump capacity must be balanced to prevent flooding the lower pond while leaving an inadequate supply of water in the upper pond
• Pondless Waterfalls

Great choice if space is lacking, you have safety concerns, or are unsure about a pond.

The system re-circulates water, creating a waterfall/stream WITHOUT a pond. You get sight and sound of running water without the maintenance or liability of a pond.

• KEY POINT

Pondless waterfalls = sight + sound, WITHOUT pond maintenance or liability. Great for safety-conscious or space-limited installations.

• Bubbling Rocks

A fast and relatively easy water feature to install. Available in a variety of sizes and options.

• Made from natural stone
• Also made by coring out stone to allow water through the centre
• Basalt columns have become very popular for use as bubbling rocks
• TEST TIP

"A bubbling rock is a fast and easy water feature to install" -> TRUE

• Fountains

Available in a range of styles and materials. Easy to install but must match pump output to achieve the desired effect. Seek professional advice for pump capacity.

• Style Rules
• Blend well with formally styled water features
• Do NOT suit informal features (fountains dont occur in nature)
• Fountain Shapes

Formal fountains create numerous shapes: water bells, single/double daisies, foaming jets, three-tiered, tulip shapes. Some manufacturers include interchangeable jets.

• Practical Notes
• Small/fine jets lost in large landscapes and tend to clog with debris
• Geyser jets (large foaming columns) less prone to clogging but disrupted by wind
• Ornamental fountains: frogs, rabbits, lionheads, gargoyles, multilevel bowls, sculptures
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9. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

• EQUIPMENT FOR WATER FEATURES

A pump is the HEART of a water feature. Depending on the type of feature, you will need some or all of the following equipment. Some pumps can be left in the water feature year-round without damage from freezing.

Koi vs. Natural Ponds: If you are planning on having Koi in a pond, a FILTRATION SYSTEM will be a necessity. A natural-looking water feature without Koi will utilize skimmers and biofalls for filtration.

• PUMPS

Modern compact submersible pumps are affordable, easy to install and maintain. Some can be left in the feature to freeze solid without harm to the pump.

Performance Specifications - Quantity of U.S. gallons moved per hour (GPH)

• Maximum lift (head) - greatest height the pump can lift water

As lift height increases, GPH output DECREASES. Inverse relationship!

• The 2x Rule

As a rule of thumb, move at least TWICE the volume of your water feature per hour.

Example: 500-gallon pond -> pump should move at least 1,000 GPH.

• Sizing Strategy

Purchase a pump with GREATER output than you believe you need. This allows:

• Adding a diverter - split output to multiple destinations (biofalls + stream)
• If flow is too high, restrict with a ball valve on the OUTPUT

NEVER restrict the INTAKE to reduce flow! Only restrict OUTPUT with a ball valve.

• Electrical Requirements

Access to a 110-volt GFCI (Ground Fault Circuit Interrupter) outlet is required.

• TEST TIP

When choosing a pump: minimum 2x volume/hour, choose greater output than needed, use ball valve to reduce - never restrict intake.

• FILTRATION SYSTEMS

Help with water clarity. Work to remove/reduce algae, collect debris and dirt.

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10. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

• Mechanical Filters

Simply trap unwanted algae and debris as water is pushed through a filtering agent. Effective but require a

GREAT amount of regular maintenance.

• Active and Passive Biological Filters

The modern, preferred system using pond skimmers and biofalls working together:

Step 1 - Pond Skimmer (Active): Pulls water from the feature, collects debris from the surface, houses the pond pump, contains filter media colonized by beneficial bacteria.

Step 2 - Beneficial Bacteria (Passive): These bacteria use nutrients in the water as their food source. Much more efficient than algae at consuming nutrients. Helps keep water clear of unsightly algae blooms.

Step 3 - Biofalls (Active): Water moves through second set of filter media with more beneficial bacteria.

Provides complete active and biological filtration.

• Biofalls Advantages
• Easy to install and maintain
• Normally require cleaning only ONCE PER YEAR
• Can be buried (start of stream) or raised (start of waterfall)
• Easy to disguise/hide - helps pond retain natural look

QUIZ ALERT: "Skimmers and Biofalls are MECHANICAL filters" = FALSE! They are BIOLOGICAL filters (active + passive with beneficial bacteria).

• HEATERS

Some people install a small floating heater to aid in overwintering fish.

Most units have a thermostat that activates at a few degrees above freezing. This keeps a small area ice-free, allowing the exchange of carbon dioxide for oxygen - a necessity if there are fish overwintering in the feature.

• KEY POINT

Floating heater purpose = NOT to warm the water. It keeps an ice-free area so CO2 can escape and O2 can enter.

Without this, fish suffocate.

• TEST TIP

Why install a floating heater? -> To help fish overwinter by allowing carbon dioxide to be released (and oxygen to enter).

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11. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

QUICK RECALL Q&A Most popular construction material? Flexible liners

Preformed ponds made from? Polyethylene or fiberglass

Is concrete ideal for prairies? NO - freeze/thaw cracks, rigid, expensive

Main waterfall/stream challenge? Water loss from evaporation

Are bubbling rocks easy to install? YES - fast and relatively easy

Can some pumps freeze solid safely? YES - some modern submersible pumps

Are skimmers/biofalls mechanical? NO - active + passive biological filters

What is puddling? Compacting clay to force out air = watertight

Which liner can be welded? BUTYL RUBBER (box-welding)

EPDM key prairie advantage? Flexible to -70C even years later

Pump output minimum? At least 2x pond volume per hour

Why never restrict pump intake? Damages pump - restrict OUTPUT only

What outlet do pumps need? 110-volt GFCI outlet

Most susceptible to punctures/UV? POLYETHYLENE (Final Exam Q8). PVC also degrades in 2-3 yrs

Why install floating heater? Ice-free area for CO2/O2 exchange

Where do fountains belong? FORMAL features ONLY How often clean biofalls? Once per year

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12. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

• EPDM warranty? 20 years (limited)

Better preformed for prairie? Polyethylene (fiberglass is brittle)

Puddled earth pond = ? Clay + large-scale + steady water = ALL

Worst durability liner type? Polyethylene (per Table 1)

Is filtration necessary for Koi? YES - filtration is a necessity

Extra problem with concrete? Lime creates additional work

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13. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

• QUIZ PREP - TRUE/FALSE

Flexible liners are the most popular material TRUE Any shape, easiest, most economical

Preformed from polyethylene/fiberglass TRUE Both available; polyethylene better for prairies

Concrete is ideal for prairies FALSE Cracks from freeze/thaw, rigid, needs curing

Waterfall challenge = evaporation TRUE Moving water over rocks = high evaporation

Bubbling rocks are fast and easy TRUE Various sizes, natural or cored stone

Some pumps freeze solid safely TRUE Modern compact submersible pumps

Skimmers/biofalls = mechanical FALSE BIOLOGICAL filters with beneficial bacteria

EPDM can be welded FALSE Only BUTYL can be welded; EPDM uses tape

PVC lasts indefinitely with UV stabilizers FALSE Deteriorates in 2-3 years in direct sun

Fountains suit formal and informal FALSE FORMAL only - not found in nature

Restrict pump intake if too much flow FALSE NEVER restrict intake; use ball valve on output

Floating heater warms the water FALSE Keeps ice-free area for gas exchange only

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14. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

CRITICAL NUMBERS TO REMEMBER Value What It Means

2x volume/hour Minimum pump output rule of thumb

• 70C EPDM stays flexible at this temperature 2-3 years PVC deteriorates in direct sunlight

20 years Typical EPDM limited warranty 20 years Life expectancy of polyethylene preformed pond

15-20 years Life expectancy of fiberglass preformed pond

4 cm Topsoil over puddled clay in earth ponds 1x per year How often biofalls need cleaning

110 volts GFCI outlet required for pump Page 14

15. LHAP 302A Water and Light | Lecture A2: Water Feature Materials

• LECTURE SUMMARY

This module introduced the various options for constructing a water feature, from lining choices to pump considerations and filtration systems.

• The Four Pond Types
• Earth ponds - rural sites with clay subsoil and natural water source
• Flexible liner ponds - most popular, three materials (butyl, PVC, EPDM)
• Preformed ponds - good for small urban settings; polyethylene preferred
• Concrete ponds - declining use; rigid, expensive, freeze/thaw damage
• Moving Water Features
• Waterfalls & streams - add sight, sound, aeration; watch for evaporation
• Pondless waterfalls - sight + sound without pond maintenance/liability
• Bubbling rocks - fast, easy, great visual impact
• Fountains - formal settings ONLY; interchangeable jets available
• Essential Equipment
• Pumps - buy bigger than needed, 2x rule, never restrict intake
• Filtration - mechanical (simple) vs biological (skimmers + biofalls)
• Heaters - floating units for CO2/O2 exchange during overwintering
• Key Takeaways
• Flexible liners = most popular, most economical construction method
• EPDM = best liner for prairies (flexible to -70C, 20-year warranty)
• Butyl = only liner that can be welded (box-welding)
• Polyethylene = most susceptible to punctures/UV (Final Exam); PVC degrades fastest in direct sun
• Concrete is NOT ideal for prairies
• Skimmers + biofalls = biological filtration (NOT mechanical)
• Pumps: buy bigger, 2x volume/hour, never restrict intake
• Floating heaters = gas exchange, not warming water

WHAT'S NEXT: Module A3 - Water Feature Construction

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