Abstract. Although it is generally accepted that wetlands have been progressively altered in large sections of the province of Ontario, little is known about the ...
WETLANDS,
THE
Vol, Z, 1982, p p . 262-270
STATUS
OF
WETLANDS
M i c h a l J. B a r d e c k i ,
IN S O U T H E R N
ONTARIO
D e p a r t m e r ~ t of A p p l i e d G e o g r a p h y
Ryerson Polytechnical Institute 50 G o u l d S t r e e t Toronto, Ontario M S E I E 8 Abstract. A l t h o u g h it i s g e n e r a l l y a c c e p t e d t h a t w e t l a n d s h a v e b e e n p r o g r e s s i v e l y a l t e r e d i n l a r g e s e c t i o n s of t h e p r o v i n c e of O n t a r i o , l i t t l e is k n o w n a b o u t t h e s t a t u s o f w e t l a n d s o r of t h e m a g n i t u d e of wetland loss in the province. An analysis of the processes acting to i m p a i r w e t l a n d a r e a s r e v e a l s t h a t a g r i c u l t u r a l l a n d d r a i n a g e e x e r t s t h e m o s t w i d e s p r e a d a n d s i s n i f i c a n t i m p a c t on w e t l a n d s . At the same t i m e , the p r a c t i c e of a g r i c u l t u r a l land d r a i n a g e does not lend i t s e l f to a d e q u a t e c o n t r o l o v e r t h e l o s s of w e t l a n d s . Drainage is most int e n s e i n t h o s e a r e a s w h e r e w e t l a n d s a r e m o s t r a r e a n d i s eontinuir~g to expand into fringe areas where wetlands may be placed in jeopardy. A g e o g r a p h i c a l a n a l y s i s of a g r i c u l t u r a l l a n d d r a i n a g e r e v e a l s a r e a s o f potential concern. INTRODUCTION Regional differences in wetland distribution are readily apparent in Ontario. Physiographic and, to a degree, climatic controls h a v e p r o d u c e d an a b u n d a n c e of w e t l a n d s in t h e c e n t r a l a n d n o r t h e r n sections of the province. Indeed, extensive peatlands cover some 90 percent of the H u d s o n B a y Lowlands in the far north (Ketcheson and 5eglum, 1972). Despite s o m e proposals for large-scale peat mining operations, to date, little pressure has been brought to bear on the wetlands of the north. In t h e s o u t h e r n s e c t i o n s of t h e p r o v i n c e , h o w e v e r , w e t l a n d s a r e a much less common feature. It i s in t h e s o u t h w h e r e m o s t of O n t a r i o rs u r b a n a n d r u r a l p o p u l a t i o n r e s i d e s , a n d i t i s c l e a r t h a t since the province was first settled, wetlands have been progressivel y d r a i n e d , d r e d g e d a n d f i l l e d . T h e m o s t r e c e n t e s t i m a t e ( S n e l l , 1982) s u g g e s t s t h a t 70 p e r c e n t of t h e o r i g i n a l w e t l a n d s in s o u t h e r n O n t a r i o had been lost by the late 1960's.
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DISCUSSION D e s p i t e l o n g - s t a n d i n g p r o p o s a l s to u n d e r t a k e a w e t l a n d i n v e n t o r y i n s o u t h e r n O n t a r i o ( D a w s o n , 1954), m a p p i n g of e x t a n t w e t l a n d s h a s n e c e s s a r i l y b e e n t h r o u g h i n t e r p r e t a t i o n of s e c o n d a r y m a t e r i a l s
(Cox, 1972; Dubsky, 1982; Snell, 1982). Wetland distributions have been estimated by the author f r o m the National Topographic ServiceCs 1:50, 000 topographic m a p series (Bardeeki, 1981). The overall pattern of wetland distribution exhibits s o m e notable features (vide Figure I). P e r h a p s m o s t s i g n i f i c a n t i s t h e g r e a t a b s e n c e of w e t l a n d s i n t h e s o u t h w e s t e r n p o r t i o n of t h e p r o v i n c e . With few exceptions, wetlands are a rare feature throughout this region. Two other sections of the province also exhibit low proportions of wetland area; the highly urbanized Lake Ontario shoreline, and the extreme eastern p o r t i o n of the p r o v i n c e . There is substantial evidence from soils data that, at least in the southwest and in the east, wetland areas were once substantial. T h e m o s t e x t e n s i v e a r e a s of r e m a i n i n g w e t l a n d s l i e i n t h e c e n t r a l s e c t i o n s of s o u t h e r n O n t a r i o , p a r t i c u l a r l y on the non-agricultural Precambrian S h i e l d a n d on the t h i n - s o i l e d limestone plains which fringe the Shield. No c o m p r e h e n s i v e a s s e s s m e n t s have been undertaken in Ontario to e v a l u a t e t h e r e l a t i v e m a g n i t u d e o f t h e v a r i o u s p r e s s u r e s which a c t t o r e d u c e w e t l a n d areas. In order to evaluate the general situation, eight study areas across southern Ontario were identified. E a c h , c o r r e s p o n d i n g to t h e c o v e r a g e o f o n e r a n d o m l y s e l e c t e d N a t i o n a l T o p o g r a p h i ~ S e r v i c e 1:50, 000 m a p , c o v e r s a n a r e a a p p r o x i m a t e l y 1 1 0 0 k s . W e t l a n d s i n d i c a t e d on e d i t i o n s of e a c h map published in the period 1966-70 were identified. Each wetland w a s c h e c k e d o n a v a i l a b l e a e r i a l p h o t o g r a p h y i n o r d e r to a s c e r t a i n t h e p r e s e n c e o r a b s e n c e of a n d r e a s o n s f o r a n y c h a n g e s u p to 1978 {the d a t e of t h e m o s t r e c e n t a e r i a l p h o t o g * a p h y ) . T h e e i g h t a r e a s c o m p r i s e o n l y a s m a l l p o r t i o n of the t o t a l area of Southern Ontario. Nonetheless, three general conclusions are noteworthy. First, agricultural drainage is the most signific a n t p r o c e s s l e a d i n g to the l o s s of w e t l a n d a r e a s . In the areas s t u d i e d , 8 5 . 0 p e r c e n t of t h e a r e a l o s t w a s a t t r i b u t a b l e to a g r i c u l tural drainage. Second, a great regional difference exists in the l o s s of w e t l a n d s . In southwestern Ontario, the actual and proportional losses far exceed those found elsewhere. The long history of a g r i c u l t u r a l d e v e l o p m e n t i n tbAs a r e a h a s e v i d e n t l y b r o u g h t t h e e x p a n s i o n of a g r i c u l t u r a l d e v e l o p m e n t i n t o c o n f l i c t w i t h t h e w e t land areas. T h i r d , the i n d i r e c t e f f e c t s of d r a i n a g e a r e a p p a r e n t l y g r e a t e r t h a n t h e d i r e c t l o s s e s of w e t l a n d s f o r a g r i c u l t u r e . In m o s t
areas, the construction of agricultural drains results in the partial
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d r a i n a g e and s u b s e q u e n t e c o l o g i c a l i m p a i r m e n t of a m u c h g r e a t e r a r e a of w e t l a n d t h a n i s a c t u a l l y c o n v e r t e d for a g r i c u l t u r a l u s e . T h e c o n s t r u c t i o n a n d m a i n t e n a n c e of a g r i c u l t u r a l d r a i n a g e i n O n t a r i o f a l l m a i n l y w i t h i n the j u r i s d i c t i o n of two p r o v i n c i a l statutes: The Drainage Act and the Tile Drainage Act.
works
W i t h i n the D r a i n a g e Act is found r e s p o n s i b i l i t y for the c o n s t r u c t i o n , i m p r o v e m e n t and m a i n t e n a n c e of o u t l e t d r a i n a g e w o r k s . The general procedure for drain construction involves the local Municip a l i t y , u p o n receipt of a petition f r o m the majority of landowners in the area requiring drainage (or fron] the owner(s) of 60 percent of that area), appointing an engineer to prepare an a s s e s s m e n t of the benefits and liabilities expected to accrue to those in the area. U p o n approval of the report, construction m a y be c o m m e n c e d . A g r a n t f r o m t h e P r o v i n c e t o c o v e r a p o r t i o n of t h e sessed against agricultural land is provided. The grant o n e - t h i r d of t h e c o s t o f t h e d r a i n a g e w o r k s . Additional grants have been available for drainage construction in tario.
cost asis generally Federal eastern On-
U n d e r t h e T i l e D r a i n a g e A c t , l o a n s of u p t o 60 p e r c e n t of t h e construction cost of on-farm drainage systems are available at a c u r r e n t i n t e r e s t r a t e o f 10 p e r c e n t . Additional capital grant funds may also be available. S e c t i o n 6 of T h e D r a i n a g e A c t a l l o w s a l o c a l m u n i c i p a l i t y , a C o n s e r v a t i o n A u t h o r i t y , o r t h e M i n i s t r y of N a t u r a l R e s o u r c e s t o g i v e n o t i c e t h a t a n e n v i r o n m e n t a l a p p r a i s a l of t h e e f f e c t s o f t h e drainage construction is required. Section 7 allows a local municip a l i t y to r e q u i r e t h a t a b e n e f i t - c o s t a n a l y s i s be p r e p a r e d . In both c a s e s t h e c o s t s of s u c h a s t u d y a r e to b e b o r n e b y t h e b o d y r e q u e s t ing it. To date, t h e s e p r o v i s i o n s h a v e b e e n u t i l i z e d m o s t i n f r e quently, and the reports requested have been prepared by drainage engineers. I n t h e i r r e v i e w of T h e D r a i n a g e A c t , F o u n d a n d S p e n c e {1977) s t a t e : " I t i s o b v i o u s t h a t e c o n o m i c a n d e n v i r o n m e n t a l c o n s t r a i n t s a r e s e c o n d a r y , and it is l i k e l y to c o n t i n u e to be v e r y diff i c u l t to s t o p e v e n t h e m o s t d a m a g i n g d r a i n a g e p r o j e c t s o n e n v i r o n m e n t a l g r o u n d s . " (p. 59). T h e s y s t e m of s u b s i d i z i n g a g r i c u l t u r a l l a n d d r a i n a g e i n O n t a r i o h a s b e e n s u b j e c t to s o m e c r i t i c i s m . In at l e a s t a l a r g e m i n o r i t y of c a s e s , a g r i c u l t u r a l b e n e f i t s h a v e n o t b e e n a s h i g h a s t h e e x p e n d i t u r e s ( F o u n d et a l , 1974). W i t h t h e c o n s i d e r a b l e admini s t r a t i v e m o m e n t u m i n v o l v e d in the d e v e l o p m e n t of a p r o j e c t and t h e l a c k of a n y e f f e c t i v e m e c h a n i s m f o r a c o m p r e h e n s i v e a s s e s s m e n t of a p r o p o s a l , t h e s i t u a t i o n i s a n i n e f f e c t i v e m e a n s o f e n s u r i n g e f f i c i e n c y of p u b l i c e x p e n d i t u r e .
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D r a i n a g e a c t i v i t y i n t h e p r o v i n c e i s c o n c e n t r a t e d in t w o a r e a s ( F i g u r e 2). I n t h e s o u t h w e s t , t h e m o s t i n t e n s e l y a g r i c u l t u r a l region in Ontario, as one moves north and west, expenditures for drainage diminish. However, it is in these "fringe" areas that a considerable recent expansion of drainage activity has taken place. A similar pattern exists in eastern Ontario. Here too, the "fringe" a r e a s ( l y i n g to t h e w e s t ) h a v e e x h i b i t e d n o t a b l e e x p a n s i o n i n t h e amount of drainage. The substantial expenditures in the generally lower capability agricultural a r e a s of e a s t e r n O n t a r i o are t o a considerable extent a reflection of the increased Federal funding which is available in this area. B y overlaying m a p s of the regional pattern of drainage and of wetland distribution, one m a y generalize on the present and future pressures on wetlands in different regions (Figure 3). Five categories of rural land are noted. Category A is found in virtually all of southwestern and eastern sections of the province. Here, wetlands form a low proportion of the land and the pressures on t h e r e m a i n i n g w e t l a n d s t h r o u g h drainage are likely to remain high. The continuing disappearance of many wetland areas in these regions may be postulated. Although the actual areas of wetlands involved may be low, their local rarity would emphasize their value. AS a r u l e , t h e m a r g i n a l s o c i a l v a l u e of resources increases with decreasing supply ceteris paribus. Private valuation of wetland areas by landholders need not (indeed it is unlikely that it would ) follow the same principle. Thus the discrepancy between public and private valuation may well be inc r e a s e d a n d t h e " t y r a n n y o f s m a l l d e c i s i o n s " ( K a h n , 1966) m a y prevail. In a few municipalities along the fringes of the m a i n areas of drainage, significant areas of wetland m a y still exist despite substantial investment in drainage (Category B). T h e s e are especially evident in eastern Ontario although they are evident in other areas. T h e wetland areas here are likely to be under pressure and the potential exists for losses of sizeable areas of wetlands. Farther on the "fringe" w h e r e drainage m a y be expected to expand in time, potential exists for even m o r e wetland losses. Although s o m e municipalities possess relatively little wetland area (Category C), m a n y contain extensive areas of wetland (Category D). Should the areal expansion of drainage continue, these are likely to progressively c o m e under pressure. Finally, ~nany areas of the province are not likely to suffer m u c h in the w a y of drainage. Wetlands here m a y be considered relatively secure f r o m agricultural drainage operations (Category
E).
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CON C LUS IONS F r o m an a n a l y s i s of P r o v i n c i a l d r a i n a g e e x p e n d i t u r e s , c a r t ographic sources, and aerial photography, a general picture emerges of t h e c u r r e n t s t a t u s of w e t l a n d s in t h e p r o v i n c e . Wetlands have b e e n d r a i n e d s o t h a t in l a r g e s e c t i o n s of t h e p r o v i n c e , e s p e c i a l l y in southwestern Ontario, they are becoming aparticularly rare land type. T h e m a j o r f a c t o r w h i c h h a s l e d to t h i s d e c l i n e in w e t l a n d s is a g r i c u l t u r a l d r a i n a g e ; o t h e r i m p a c t s , a l t h o u g h of p e r h a p s l o c a l s i g n i f i c a n c e , do n o t c o n s t i t u t e a s g r e a t a q u a n t i t a t i v e o r as w i d e spread a threat as does agriculture. The practice of agricultural l a n d d r a i n a g e i n t h e p r o v i n c e d o e s not p r o v i d e f o r a d e q u a t e c o n t r o l o v e r t h e l o s s of w e t l a n d s . What is p e r h a p s m o s t i m p o r t a n t , is the fact that the g r e a t e s t p r e s s u r e on w e t l a n d s a r i s e s in j u s t t h o s e a r e a s w h e r e t h e y a r e most rare. In a d d i t i o n , a g r i c u l t u r a l l a n d d r a i n a g e i s e x p a n d i n g i t s i n f l u e n c e in t h e p r o v i n c e . It m a y b e e x p e c t e d t h a t t h o s e a r e a s on t h e " f r i n g e s " of c u r r e n t d r a i n a g e i n t e n s i t y , w h e r e w e t l a n d s a r e currently under little pressure, ~-[11 in t h e f u t u r e c o m e u n d e r i n c r e a s e d d r a i n a g e a c t i v i t y w i t h c o n s e q u e n t l o s s e s of w e t l a n d s . Cons e r v a t i o n e f f o r t s to p r o t e c t w e t l a n d a r e a s m u s t , t h e r e f o r e , d e a l with both issues: one, the protection of the few remaining wetlands i n a r e a s of h i g h a g r i c u l t u r a l i n t e n s i t y ; and, t w o , t h e r a t i o n a l i z a t i o n of a d r a i n a g e p o l i c y w h i c h e n c o u r a g e s o v e r - i n v e s t m e n t i n d r a i n a g e t o t h e d e t r i m e n t of w e t l a n d s i n t h e " f r i n g e " a r e a s . It i s not clear whether a single policy can achieve both. ACKNOWLEDGEMENTS
This research was funded in part bythe Ontario Career Action P r o g r a m , the Wildlife Branch, Ministry of Natural Resources and the Social Sciences and Humanities Research Council (general research grant). Cartography was prepared by the Cartographic Office, Department of Geography, York University. LITERATURE Bardecki,
CITED
M.J., 1981. W e t l a n d c o n s e r v a t i o n p o l i c i e s i n s o u t h e r n Ontario: A Delphi analysis. Ph. D Dissertation, York University, Toronto, Ontario. 467 pp.
Cox, E.T., 197Z. Estimates of cleared wetlands in southern Ontario. Ontario Ministry of Natural Resources, Toronto, Ontario. 6 pp.
WETLANDS,
Z70 Dawson,
Vol, Z, 1982
J . B . , 1954. C o n s i d e r a t i o n s r e g a r d i n g a w e t l a n d i n v e n t o r y for southern Ontario. Fish and Wildlife Management Report (Ontario} 49:16-19.
Dubsky, H.L., 1982. M a r s h inventory for southv~estern Ontario. Pages Z7-34 i n M . J. Bardecki, ed. Wetlands Research in Ontario. Department of Applied Geography, Ryerson ]:*olyteehnical institute, Toronto, Ontario. Found,
Win. C., A. R. H i l l a n d E . S . S p e n c e , 1974. E c o n o m i c a n d e n v i r o n m e n t a l i m p a c t s of l a n d d r a i n a g e in O n t a r i o . A t k i n s o n C o l l e g e G e o g r a p h i c a l M o n o g r a p h 6, Y o r k U n i v e r sity, Toronto, Ontario. 175 pp.
Found, wrn. C.and E. S. S p e n c e , 1977. T h e D r a i n a g e A c t 1975: I t s evolution and possible impacts. Canadian Water Resources Journal 2:51-61. Kahn, A . E . , 1966. T h e t y r a n n y of s m a l l d e c i s i o n s : M a r k e t f a i l u r e s , imperfections, and the limits of economics. Kyklos 19:23-47. K e t c h e s o n , D . E . a n d f f . K . J e g l u m , 197Z. E s t i m a t e s of h l a c k s p r u c e and p e a t l a n d a r e a s in O n t a r i o . Great Lakes Forest Research Centre Information Report O - X - 172, Sault Ste. Marie, Ontario. 29 pp. Snell,
E . , 1982. An a p p r o a c h to m a p p i n g t h e w e t l a n d s of s o u t h e r n Ontario. P a g e s 1-26 in M . J . B a r d e c k i , ed. W e t l a n d s R e search in Ontario. Department of Applied Geography, Ryerson Polytechnlcal Institute, Toronto, Ontario.
