GEOLOGICAL SURVEY CIRCULAR 601-K An Introduction to the Processes, Problems, and Management of Urban Lakes An Introduction to the Processes, Problems, and Management of Urban Lakes By L. J. Britton, R. C. Averett, and R. F. Ferreira WATER IN THE URBAN ENVIRONMENT G E 0 l 0 G I C A l S U R V E Y C I R C U l A R 601-K 1975 United States Department of the Interior ROGERS C. B. MORTON, Secretary Geological Survey V. E. McKelvey, Director First printing 1975 Second printing 19 77 Free on application to U.S. Geological Survey, National Center, Reston, Va 22092 CONTENTS Page Page Glossary of selected terms ....................... IV Planning and management of watersheds and lakes Conversion factors ............................. VI for water quality control--Continued Abstract ..................................... 1 Watershed management . 13 Man and his lakes .............................. 1 Lake management . 13 What this report is all about ...................... 2 Water quality control . 13 Physics, chemistry, and biology of lakes ............ 2 Algal blooms . 13 Physical characteristics ..................... 2 Light penetration ...................... 2 Anaerobic conditions . 14 Temperature ......................... 3 Fish kills . 15 Suspended sediment ................... 5 Sediment deposition . 15 Morphology .......................... 5 Summary of management options . 15 Chemical characteristics ..................... 5 Conducting lake studies . 15 Major chemical constituents ............. 5 Measuring the properties of lakes . 16 Minor chemical constituents ............. 5 Physical measurements . 16 Major plant nutrients ................... 6 Mapping.......................... 16 Dissolved gases ........................ 6 Temperature . 16 Biological characteristics .................... 6 Light penetration . 17 Plankton ............................ 6 Chemical measurements . 17 Benthos ............................. 6 Dissolved oxygen . 17 Nekton ............................. 6 Alkalinity and pH . 17 Processes in lakes .............................. 9 Major chemical constituents and Photosynthesis and respiration ............... 9 specific conductance . 17 Eutrophication ........................... 10 Minor chemical constituents . 18 The biogeochemical cycle ................... 10 Major plant nutrients . 18 Sedimentation ........................ 11 Biological measurements . 19 Nutrient cycling ....................... 11 Phytoplankton and periphyton . 19 Planning and management of watersheds and lakes Zooplankton . 20 for water quality control ...................... 12 Benthic invertebrates . 20 Lake basin planning ........................ 12 References cited . 21 ILLUSTRATIONS Page Figure 1. The major life zones of a lake . 3 2. Seasonal thermal profiles of a warm monomictic lake . 4 3. Representative lake organisms . 9 4. Effect of man upon the eutrophication of lakes . 11 5. Sources and cycling of elements in a lake . 12 6. Typical growth pattern of blooming unicellular algae . 14 TABLE Page Table 1. Common forms, minimum requirements, and some sources of elements essential for the growth of algae 7 III GLOSSARY OF SELECTED TERMS [Many of the definitions in this glossary were obtained or modified from Slack and others (1973).] Absorption (n). To take up and incorporate within the Consumer (n). An organism that is unable to manufac­ body. ture its food from nonliving matter and is dependent Adsorption (n). To take up and hold by adhesion to the on the energy and materials stored in other living surface. things. Aerate (v), aerator (n). To charge or treat with air or Decomposition, decomposer (n). The breakdown of other gases, usually with oxygen. dead plant and animal tissue by bacteria to the Aerobic (adj). Having oxygen. elemental state. Alga, algae (n), algal (adj). A group of simple primitive Density (n). The quantity or mass of a substance per plants that live in wet or damp places, and generally unit volume. Computed as grams per cubic centi­ are microscopic in size, containing chlorophyll and metre, in the case of water. lacking roots, stems, and leaves. Detritus (n). Fragmented material of inorganic or Algal bloom (n). A high concentration of a particular organic origin. algal species, amounting to ~ million to I million Diatom (n). A unicellular or colonial alga having a cells per litre of water or more. siliceous shell. Algicide ( n). A chemical that kills algae. Dinoflagellate (n). A typically yellow-brown unicellular Anaerobic {adj). Devoid of oxygen. alga that swims by means of two laterally attached Assimilation (n), assimilate (v). To take up or incor­ appendages called flagella (fig. 3). Dystrophic (adj). Brown-water lakes with a very low porate within the body. Technically, secondary pro­ lime content and a very high humus content, often ductivity plus respiration and other losses. characterized by a severe lack of nutrients (Ruttner, Autumn overturn (n). The mixing of the entire water 1963, p. 254). mass of a lake in the autumn. Ecosystem (n). The community of plants and animals Bacterium, bacteria (n), bacterial {adj). Microscopic interacting together with the physical and chemical unicellular organisms. Some bacteria cause disease environment. while others perform an essential role in the recycling Emersed plant (n). A rooted aquatic plant with leaves or of materials. other structures extending above the water surface Benthos, benthic zone (n). Organisms living in or on the (sometimes called emergent plant). bottom of an aquatic environment. The bottom of a Enrichment (n). Addition or accumulation of plant lake or stream. nutrients within a body of water (Greeson, 1971, Biochemical oxygen demand (BOD) (n). The quantity of P• 139). 1 Environment (n). The sum of all the external physical, dissolved oxygen, in milligrams per litre, used for the chemical, and biological conditions and influences decomposition of organic material by microorga­ that affect the life and development of an organism. nisms, such as bacteria. Epilimnion (n), epilimnetic (adj). The upper, relatively Biomass (n). The amount of living matter present in a warm, circulating zone of water in a thermally unit area or volume, at any given time. stratified lake. Biota (n), biotic (adj). All the plants and animals in a Erosion (n). The general process or group of processes particular area. whereby the materials of the Earth's crust are Blue-green algae (n). A group of algae with a blue loosened, dissolved, or worn away, and removed from pigment, in addition to the green chlorophyll. Blue­ one place to another by weathering, solution, cor­ green algae group usually causes nuisance conditions rasion, and transportation (Gary and others, 1972). in water. Euphotic zone (n). That part of the aquatic environment Carbohydrate (n). Chemical compounds containing car­ where light penetration is sufficient for photosyn­ bon, hydrogen, and oxygen, such as sugars, starches, thesis. Refers to the combined littoral and limnetic or celluloses. Most are formed by green plants and zones of lakes. serve as basic food units for animals. Eutrophication (n), euthrophic (adj). The natural Compensation level or depth (n). The depth of water at process of enrichment and aging of a body of water which oxygen production by photosynthesis balances that may be accelerated by the activities of man. oxygen uptake by respiration of plants and animals. Pertains to water bodies in which primary production The depth is usually where light intensity is reduced is high because of a large supply of available to about 1 percent of the surface light (Odum, 1971, nutrients. (See also Dystrophic, Mesotrophic, and p. 301). Oligotrophic.) IV Fauna (n), faunal (adj). A collective term for all the Monitoring (n). A type of sampling program designed to types of animals in an area. determine time-trend changes. Food chain (n). The transfer of food energy and Monomictic ( adj). Lakes having only one circulation materials from plants through other organisms, with period per year. repeated eating and being eaten. Nekton (n). Actively swimming aquatic organisms, such Fungus, fungi (n). Plants lacking chlorophyll, including as fish. molds, yeasts, mildews, rusts, and mushrooms. Nutrient (n). Any chemical element, ion, or compound Grab (n). An instrument designed to "bite" into the that is required by an organism for the continuation bottom sediment of a lake or stream to sample the of growth, reproduction, and other life processes. bottom materials and the benthos. Nymph (n), nymphal (adj). An immature stage of an Green algae ( n). Algae that have pigments similar in insect in which the body form resembles the adult. color to those of higher green plants. Some forms (See also Larva.) produce algal mats or floating "moss" in lakes. Oligotrophic (adj). Pertaining to waters in which primary Heterotroph (n), heterotrophic (adj). An organism that production is low as a consequence of a small supply requires organic material as a source of nutrition; of available nutrients. includes all animals and most bacteria. Organic (n). Pertaining or relating to a compound Homothermous ( adj). At the same temperature through­ containing carbon. out. Oxidation (n). The process in which oxygen chemically Hypolimnion (n), hypolimnetic (adj). The lower, rela­ combines with a substance, or in which an element tively cold, non-circulating water zone in a thermally loses electrons. stratified lake. Periphyton (n), periphytic (adj). The community of Interpretative (adj). A type of sampling program or microorganisms, such